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NEET MCQs Reproduction in Organisms Sample
- Clone is two or more individuals which are similar:
a) Genetically b) Morphologically c) Sexually d) Both (A) and (B) - Which of the following is wrongly matched pair?
a) Tuber-Potato b) Rhizome-Ginger c) Bulbil-Agave d) Leaf buds-Banana - Bamboo species flower only in
a) 50-100 yrs b) 25-50 yrs c) 75-100 yrs d) 60-80 yrs - Somaclonal variation appears in plants:
a) Growing in polluted soil or water b) Exposed to gamma rays
c) Raised in tissue culture d) Transformed by recombinant DNA technology - During favourable conditions, π΄πππππ reproduces by:
a) Binary fission b) Multiple fission c) Both of these d) None of these - Asexual reproduction in plants is called
a) Vegetative reproduction b) Syngamy
c) Parthenocarpy d) Parthenogenesis - Identify the following diagram
a. Zoospore in πΆβππππ¦πππππππ
b. Conidia of ππππππππππ’π
c. Buds in π»π¦πππ
d. Gemmules in sponge
All the above are
a) Bodies involved in sexual reproduction b) Bodies involved in asexual reproduction
c) Bodies of young ones d) All the above are correct
- The process of release of egg from the ovary is called:
a) Reproduction b) Ovulation c) Menstruation d) Insemination - Juvenile phase in plants, is
a) Vegetative phase b) Reproductive phase c) Growth phase d) Senescence phase - Essential and most critical event in sexual reproduction is
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a) Fertilization b) Fusion of male and female gemetes
c) Division in male and female gametes d) Both (a) and (b)
- The above figure depicts
a) Budding b) Binary fission c) Fission d) Zoospore - Find out correct order of vegetative propagules of plants like potato, ginger, Agave, Bryophyllum and
water hyacinth
a) Offset, bulbil, leaf bud, rhizome and eyes b) Leaf bud, bulbil, offset, rhizome and eyes
c) Eyes, rhizome, bulbil, leaf bud and offset d) Rhizome, bulbil, leaf bud, eyes and offset - Nuclear membrane is absent in:
a) Monera b) Protista c) Fungi d) Plantae - π΅ππ¦ππβπ¦πππ’π can be propagated vegetatively by:
a) Stem b) Root c) Leaf d) Flower - Self-fertilisation occurs in the
a) Bisexual flower b) Unisexual flower c) Both (a) and (b) d) Monoecious flower - Vegetative propagation in πππ π‘ππ occurs by:
a) Stolon b) Offset c) Runner d) Sucker - One of the followings is not the characteristic feature of cyanobacteria:
a) They are multicellular b) They form colonies
c) They form blooms in polluted water bodies d) They can fix atmospheric nitrogen - The condition, in which, both male and female reproductive organs are found on the same plant, is called
a) Unisexual b) Bisexual c) Both (a) and (b) d) Monoecious - Male gametes are also called
a) Antherozoid b) Sperm c) Egg d) Both (a) and (b) - Bamboo plant flowers only once in their life time, generally 50-100 years, produce larger number of fruits
and die. Blue stretches were formed by flowering of plant. ππ‘ππππππππ‘βπ’π ππ’ππ‘βππππ in Kerala, Karnataka
and Tamil Nadu. It flowers once in how many years?
a) 15 years b) 12 years c) 20 years d) 48 years - The βeyesβ of the potato tubers are:
a) Root buds b) Flower buds c) Shoot buds d) Axillary buds - Who worked on embryological aspects and popularized the use of embryological characters in taxonomy?
a) P. Guha b) P. Maheshwari c) Ivanovosky d) D. Graaf - Vegetative propagation by leaf takes place in:
a) Ginger b) π΅ππ¦ππβπ¦πππ’π c) Rose d) π·π’ππππ‘π - Binary fission is the mode of asexual reproduction in
a) Amoeba b) Paramecium c) Both (a) and (b) d) Yeast - The part where fertilization of ovum takes place in rabbit, humans and other placental mammals is:
a) Ovary b) Uterus c) Vagina d) Fallopian tube - Grafting is used to propagate plants because:
a) It is faster than seeds
b) It maintains a desired set of genetic characteristics
c) It combines the genetic characteristics of two desirable plants
d) A plant can produce many more scions than seeds - Seasonal breeders are the organisms which reproduces during
a) Favourable season only b) Unfavourable season only
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c) Maturation period d) Juvenile period
- Flower ππ π»ππππ ππ’π is:
a) Bisexual b) Unisexual c) Neuter d) Very small - Life span of Cow is 20-25 years. What is the life span of horse?
a) 140 years b) 20-30 years c) 100-150 years d) 60 years - βBisexual animals that possess both male and female reproductive organs are called hermaphroditeβ. The
above statement is
a) True b) False
c) Sometimes (a) and sometimes (b) d) Neither (a) and (b) - Regeneration of a plant cell to give rise to new plant is called:
a) Reproduction b) Budding c) Totipotency d) Pleuripotency - Which of the following is hermaphrodite?
a) Ant b) Aphids c) Earthworm d) Cockroach - The separation of single cell from the rest of the callus is:
a) Organ culture b) Tissue culture c) Basal medium d) Nurse tissue - Vivipary is observed in:
a) Banyan b) π΅ππ¦ππβπ¦πππ’π c) πΌπππππ d) π βππ§ππβπππ - Vegetative propagation in πππ π‘ππ occurs by:
a) Stolon b) Offset c) Runner d) Sucker - π
βππ§πππ’π reproduces asexually by:
a) Conidia b) Spores c) Gemma d) Bulbil - Reproduction is a biological process in which an organism give rise to young ones (offspring) similar to
itself. An organismβs method of reproduction depends upon factors:
a) Habitat b) Internal physiology c) Genitalia d) All of above - Use of stem cutting is common method of vegetative propagation. Juvenile wood grows roots more readily
than mature wood. The superior rooting of juvenile cutting may be due to:
a) Lower ABA contents b) Higher endogenous auxin contents
c) Higher endogenous gibberellins contents d) They being still in the vegetative stage - Events in the diagram are (in sequential order) a) Fission of gametes β new individual β zygote
b) Fusion of gametes β zygote β new individual (cell 2π)
c) Fission of gametes β zygote β new individual (cell 2π)
d) Stages in the gametogenesis - Examples of vegetative propagation are
a) Rhizome b) Tuber c) Offset d) All of these - Gametogenesis is the formation of
a) Male gamete b) Female gamete c) Both (a) and (b) d) Spore - Which of the following require water for gamete transfer?
a) Algae, bryophytes and pteridophyte b) Pteriodophyles only
c) Gymnosperms d) Angiosperms - During embryogenesis the zygote undergoes
a) Cell division (mitosis) b) Cell division (meiosis)
c) Cell differentiation d) (a) followed by (c) - Find out the wrong pair with respect to number of chromosomes in meiocytes:
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a) Fruit fly -8 b) Apple -36 c) Rice -24 d) House fly -12
- Which of the following is pollinated by water?
a) Viola b) Yucca c) Oxalis d) Zostera - Large number of offspring produced in the case of
a) Fertilization that occur in external medium
b) Fertilization that occur in internal medium
c) Either (a) or (b)
d) Both (a) and (b) - The period from birth to natural death is called
a) Life span b) Life cycle c) Life style d) Reproductive phase - Reproduction takes place in which stage of life span
a) Juvenile stage b) Maturation stage c) Reproductive stage d) Ageing phase - In case of Marchantia, antheridiophore is produced by:
a) Female thallus b) Male thallus c) Monoecious plant d) None of above - Identify the gametes in fig π΄,π΅ and πΆ a) A-Heterogametes, B-Isogametes, C-Homogametes
b) A-Homogametes, B-Isogametes, C-Heterogametes
c) A-Isogametes, B-Heterogametes, C-Heterogametes
d) A-Heterogametes, B-Heterogametes, C-Isogametes - Isogamous condition with non-flagellated gametes is found in:
a) Spirogyra b) Volvox c) Fucus d) Chlamydomonas - Which of the following statement support the view that elaborate sexual reproductive processes appeared
much later in organic evolution?
I. Lower groups of organisms have complex body design
II. Asexual reproduction is common in lower groups
III. Asexual reproduction is common in higher groups of organisms
IV. High incidences of sexual reproduction are visible in angiosperms and vertebrates
a) I and II b) I and IV c) II and IV d) II and III - Name the plants, the structures of which are given in the previous question and select the correct answer
the given option
A B C D E a) Pot
ato
Gin
ger
Bryop
hyllu
m
Water
hyaci
nth
Agave b) Pot
ato
Gin
ger
Water-
hyaci
nth
Agave Bryop
hyllu
m
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c) Pot
ato
Gin
ger
Bryop
hyllu
m
Agave Water
hyaci
nth
d) Pot
ato
Gin
ger
Agave Bryop
hyllu
m
Water
hyaci
nth
- Parameters of old age are
a) End of reproductive phase b) Concomitant changes in the body
c) Slowing down of vital process d) All of the above - Bud grafting is commonly used in:
a) Litchi b) Pomegranate c) Rose d) Jasmine - Immortal individuals are
a) Single celled organisms b) Double celled organisms
c) Multi-celled organisms d) Green plants - Air layering is performed in case of:
a) Jasmine b) Grapevine c) Goose berry d) Litchi - Product of sexual reproduction generally generates:
a) Prologned dormancy b) New genetic combination leading to variation
c) Large biomass d) Longer viability of seeds - When mature anthers of π·ππ‘π’ππ πππ₯ππππ are cultured in a culture medium supplemented with
phytohormone named kinetin, coconut milk and plum juice, several embryos can be obtained floating
inside the microsporangia. These embryos can develop into plants that are:
a) Haploid b) Diploid c) Tetraploid d) Both (A) and (B) - In papaya, the flowers, are:
a) Unisexual b) Bisexual
c) Neuter d) Flowers are not formed - In oviparous individuals the fertilized egg is covered by
a) Calcareous shell b) Phosphorus cell c) Both (a) and (b) d) Hard shell - Improved method of grafting is:
a) Both scion and stock plants are allowed to remain
intact
b) Stock and scion are given oblique cuts
c) Both (A) and (B) d) None of the above - Banana is multiplied by means of:
a) Seeds b) Leaf margins c) Rhizome d) Offsets - Breeding of crops with high levels of minerals, vitamins and proteins is called:
a) Somatic hybridization b) Bioforfication
c) Micropropagation d) Biomagnification - Life begin in all sexually reproducing organism from
a) Single celled zygote b) Double celled zygote c) Haploid zygote d) From gametes - Konar and Nataraja demonstrated callus π.π., embryoids in buttercup also develops from:
a) Pith cells b) Mesodermal cells
c) Epidermal cells of hypocotyl region d) Cortex cells - Clones are
a) Morphologically similar individuals b) Genetically similar individuals
c) Both (a) and (b) d) None of the above - Micropropagation is based on:
a) Tissue culture b) Hybridization c) Microtomy d) Genetic control - Grafting is attempted in those plants which show:
a) Adventitious roots b) Buds
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c) Folliage leaves and herbaceous stems d) Secondary growth
- Chances of survival of young ones is greater in:
a) Fishes b) Eutherian mammals
c) Birds d) Amphibians - In potato, vegetative propagation takes place by:
a) Root b) Leaf c) Grafting d) Stem tuber - Offsprings formed by sexual reproduction exhibit more variation than those formed by asexual
reproduction because
a) Sexual reproduction is a lengthy process
b) Gametes of parents have quantitatively different genetic composition
c) Genetic material comes from two parents of same species
d) Greater amount of DNA is involved in sexual reproduction - Syngamy means:
a) Fusion of similar spores b) Fusion of dissimilar spores
c) Fusion of cytoplasm d) Fusion of gametes - βGemmule formation is a common mode of reproduction in πππππππππ’πβ
a) True b) False
c) Sometimes (a) and sometimes (b) d) Neither (a) nor (b) - ππ‘ππππππππ‘βπ’π ππ’ππ‘βππππ is also called
a) Neela Kuranji b) Peela Kuranji c) Hara Kuranji d) Violet Kuranji - π»π¦πππ reproduces by binary fission. This sentence is
a) True b) False
c) Sometimes (a) and Sometimes (b) d) Neither (a) nor (b) - Vegetative type of reproduction means:
a) Plant portion is used as a means of propagation
b) Seed is used as a means of propagation
c) Flower is used as a means of propagation
d) None of the above - Transverse binary fission occurs in
a) Euglena b) Amoeba c) Hydra d) Paramecium - In vegetative propagation, characters of parent plants are:
a) Changed b) Not preserved c) Preserved d) Exchanged - Asexual reproduction is a method of reproduction in which participation of β¦β¦β¦ takes place
a) One individual b) Two individuals c) Multi-individuals d) Meiosis - Common mode of reproduction in ππππππππππ’π is
a) Conidia b) Buds c) Gemmules d) Zoospore - An example of corm is
a) Ginger b) Colocasia c) Onion d) Potato - Corm is modification of:
a) Root b) Leaf c) Stem d) Bud - Female gametes are also called
a) Egg b) Ovum c) Both (a) and (b) d) Antherozoid - Which of the following have haploid plant body in most of organisms?
a) Monera b) Fungi
c) Algae and Bryophytes d) All of above - The most significant value of vegetative propagation is that:
a) It enables rapid production of genetic variation
b) It is a means of producing a large population of individuals genetically identical to the parent
c) It ensures that the progeny are safe from attack of diseases and practice
d) It is an ancient practice
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- Embryogenesis is process of development of embryo from the zygote. During this process zygote
undergoes:
a) Meiosis b) Cell division (mitosis)
c) Cell differentiation d) Both (B) and (C) - Embryo sac is found in:
a) Endosperm b) Embryo c) Ovule d) Seed - π»π¦πππ reproduces asexually through:
a) Fragmentation b) Budding c) Binary fission d) Sporulation - Eyes on the potato, sugar cane, ginger are
a) Condensed nodes b) Condensed internode
c) Interspread rhizome d) Interspread corm - Which one of the following is correctly matched?
a) Ginger-Sucker b) πΆβππππ¦πππππππ -Conidia
c) Yeast-Zoospores d) Onion-Bulb - Period of pregnancy is called:
a) Gestation period b) Incubation period c) Pre-patent period d) Blastulation - Menstrual cycle is completed in:
a) 30 Days b) 31 Days c) 28 Days d) 27 Days - Reproduction is
a) Biological process of producing young ones
b) Non-biological process of producing young ones
c) Biological process of producing mature ones
d) None of the above - Why water hyacinth is called Terror of Bengal?
a) It is being used as food for fish
b) It consumes oxygen from cultivated plant and destroy them
c) It consumes oxygen from water and decreases O2 concentration in water
d) It is a weed - Development of fruit without fertilization is called:
a) Cell division b) Cell culture c) Parthenocarpy d) Parthenogenesis - Give the name of the following diagram a) A-Male cockroach, B-Funaria, C-Unisexual flower
b) A-Male cockroach, B-Marchantia, C-Bisexual flower
c) A-Female cockroach, B-Cycas, C-Unisexual flower
d) A-Female cockroach, B-Marchantia, C-Bisexual flower - In diploid organism the gamete producing cells are called
a) Gamete mother cell b) Meiocytes c) Both (a) and (b) d) None of these - Clone is a group of individuals got through:
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a) Self pollination b) Cross pollination
c) Vegetative propagation d) Hybridization
- Zoospores are
a) Motile gametes b) Female motile gametes
c) Sessile gametes d) Female sessile gametes - In oviparous individuals development of zygote takes place
a) Outside the body b) Inside the body
c) Inside the freshwater d) Inside the marine water - Which is correct about anthers. They are:
a) Haploid b) Diploid
c) Diploid as well as triploid d) Haploid, diploid and triploid - In grafting scion forms:
a) Shoot system b) Root system c) New plant d) Hybrid plant - Vegetative propagation in mint occurs by:
a) Runner b) Offset c) Rhizome d) Sucker - Division in a bacterial cell is carried out through
a) Multiple fission b) Binary fission c) Budding d) Plasmotomy - During oogenesis, each diploid oocyte produces:
a) Four functional ova b) Two functional eggs and two polar bodies
c) Four functional polar bodies d) One functional egg and three polar bodies - Choose the option with correct identification of π΄,π΅,πΆ,π· and πΈ given below:
A B C D E
a) Tuber Rhizome Eyes Leaf
bud
offset
b) Offse
t
Eyes Leaf
bud
Stolon Suck
er
c) Offse
t
Leaf
buds
Eyes Stolon Suck
er
d) Tuber Rhizome Bulbil Leaf
buds
offset
- Which one of the following pairs is wrongly matched, while the remaining three are correct?
a) π΅ππ¦ππβπ¦πππ’πβ Leaf buds b) π΄gππ£πβBulbils
c) ππππππππππ’πβConidia d) Water hyacinth βrunner - βUnisexual male flower is called pistillateβ. The above statement is
a) True b) False
c) Sometimes (a) and sometimes (b) d) Neither (a) nor (b) - In which of the following organisms self fertilisation is seen?
a) Fishes b) Leech c) Earthworm d) Liverfluke - One of the following is not a method of asexual reproduction:
a) Cutting b) Grafting c) Budding d) Conjugation - Parthenogenesis is the process in which new organism is formed
a) With fertilization b) Without fertilization c) Through mitosis d) Through meiosis
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- Internal fertilization is the one in which syngamy
a) Occur outside the body b) Occur inside the body
c) Followed by meiosis d) None of these - Terror of Bengal is
a) Freshwater plant called water lily b) Marine plant called water propagules
c) Aquatic plant called water hyacinth d) None of the above - A scion is grafted to stock. The quality of fruits produced will be determined by the genotype of:
a) Stock b) Scion
c) Both stock and scion d) Neither stock nor scion - Oestrus cycle is cyclic changes in the activities of ovaries and accessory duct during
a) Reproductive (seasonal) period b) Maturation period
c) Ageing period d) Juvenile period - βUnisexual female flower is called staminateβ. The above statement is
a) True b) False
c) Sometimes (a) and sometimes (b) d) Neither (a) nor (b) - Animals giving birth to young ones are:
a) Oviparous b) Ovoviviparous c) Viviparous d) Both (B) and (C) - Pollination is
a) Transfer of gametes on stigma b) Transfer of male gametes on stigma
c) Transfer of female gametes on stigma d) Fusion of male and female gametes - What is common between vegetative reproduction and apomixis?
a) Both occur round the year b) Both produce progeny identical to the parent
c) Both are applicable to only dicot plants d) Both bypass the flowering plant - In which pair both the plants can be vegetatively propagated by leaf pieces?
a) π΅ππ¦ππβπ¦πππ’π and πΎπππππβππ b) πΆβππ¦π πππ‘βπππ’π and π΄gππ£π
c) π΄gππ£π and πΎπππππβππ d) π΄π ππππgπ’π and π΅ππ¦ππβπ¦πππ’π - Which is not a method of vegetative propagation?
a) Micropropagation b) Sowing c) Budding d) Layering - Micropropagation is a technique for the production of
a) New plant b) Haploid pants c) Hybrid variety d) Somaclonal plants - Largest bird is:
a) Emu b) Penguin c) Kiwi d) Ostrich - Diploid zygote is universal in
a) All sexually reproducing organisms
b) All asexually reproducing organisms
c) All sexually and asexually reproducing organisms
d) All plants and animals - The condition in which male and female parts present on the different plant, is called
a) Heterothallic b) Dioecious c) Unisexual d) All of these - Cell division is the mode of reproduction in
a) Monera b) Protista c) Both (a) and (b) d) Plants - Man is:
a) Unisexual b) Bisexual c) Hermaphroditic d) Protogynous - Events in the sexual reproduction
I. Pre-fertilisation
II. Fertilisation
III. Post-fertilisation
The sequential order of their occurrence is
a) IβIIIβII b) IIβIβIII c) IIIβIIβI d) IβIIβIII - Asexual reproduction is carried out by:
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a) Single parent b) Without fusion of gametes
c) With or without formation of gametes d) All of above
- The living organisms can be unexceptionally distinguished from the non-living things on the basis of their
ability for:
a) Interaction with environment and progressive evolution
b) Reproduction
c) Growth and movement
d) Responsive to touch - Fusion of male and female gametes is called
a) Syngamy b) Fertilization c) Both (a) and (b) d) Heterogamy - Meiosis takes place in:
a) Conidia b) Gemmule c) Megaspore d) Meiocyte - Which one is female gametophyte?
a) Embryo b) Embryo sac c) Endosperm d) Synergid - Callus is a
a) Organized mass of the cell b) Differentiated mass of the cell
c) Dedifferentiated mass of the cell d) Undifferentiated mass of the cell - The technique of obtaining large number of plantlets by tissue culture method is called
a) Plantlet culture b) Organ culture c) Micropropagation d) Macropropagation - Stem cuttings are employed in the propagation of:
a) Banana b) Mango c) Sugar cane d) Cotton - Embryogenesis is the process of development of
a) Embryo b) Endosperm c) Individual d) Internal organs - Which of the following is correct about Neela Kuranji?
a) Last time it was flowered in Sept-Oct.2006
b) Next time it will have flower in Sept-Oct.2018
c) It is found in Kerala, Tamil Nadu and Karnataka
d) All of the above - Vegetatively propagated plants:
a) Clone of their parent b) Show adaptive variations
c) Better fitted for struggle for existence d) Stouter than parents - Menstrual cycle is
a) Seasonal hormonal ovarian change b) Conditional hormonal ovarian change
c) Periodic hormonal ovarian change d) Habitual hormonal ovarian change - If the parent body is haploid then the gametes are
a) Haploid b) Diploid c) Triploid d) None of these - Which of the following is not immortal?
a) Banyan tree b) Amoeba c) πΈπ’gππππ d) πππππππππ’π - Even in absence of pollinating agents seed-setting is assured in:
a) πππ π‘πππ b) ππππ£ππ c) Fig d) πΆπππππππππ - Many scientists consider viruses as living entities because these:
a) Respire b) Can cause diseases
c) Reproduce (inside host) d) Respond to tough environment - Where does syngamy occur in β¦β¦..
a) External medium b) Internal medium c) Both (a) and (b) d) None of these - Micropropagation is a technique:
a) For production of true to type plants b) For production of haploid plant
c) For production of somatic hybrids d) For production of somaclonal plants - Scion is the term used in relation to:
a) Embryology b) Grafting c) Agamospermy d) Emasculation
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- The DNA in the cell β¦β¦.. is the information source for making proteins:
a) Nucleus b) Ribosome c) Cell wall d) Plasma membrane - Female gamete undergoes development to form new organisms without fertilization. The process called
parthenogenesis. It occurs in:
a) Rotifers b) Turkey birds c) Some reptiles d) All of above - Zygote develops into:
a) Embryo b) Ovule c) Seed d) Fruit - Asexual reproduction is common in
a) Single celled organisms
b) Plants with relatively simple organization
c) Animals with relatively simple organization
d) All of the above - The mode of asexual reproduction in bacteria are:
a) Formation of gametes b) Endospore formation
c) Conjugation d) Zoospore formation
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NEET BIOLOGY
REPRODUCTION IN ORGANISMS
: ANSWER KEY :
1) d 2) d 3) a 4) c
5) a 6) a 7) c 8) b
9) a 10) d 11) a 12) d
13) b 14) c 15) a 16) b
17) a 18) c 19) d 20) b
21) d 22) b 23) b 24) c
25) d 26) d 27) a 28) a
29) d 30) a 31) c 32) c
33) d 34) d 35) b 36) d
37) d 38) c 39) b 40) d
41) c 42) a 43) d 44) b
45) d 46) a 47) a 48) b
49) b 50) c 51) a 52) c
53) d 54) d 55) c 56) a
57) a 58) b 59) b 60) a
61) d 62) c 63) c 64) b
65) a 66) d 67) c 68) a
69) d 70) b 71) d 72) c
73) d 74) b 75) a 76) b
77) c 78) d 79) c 80) a
81) a 82) b 83) b 84) c
85) d 86) d 87) d 88) c
89) b 90) a 91) d 92) a
93) c 94) a 95) c 96) c
97) d 98) c 99) a 100) a
101) a 102) a 103) a 104) a
105) b 106) b 107) d 108) d
109) b 110) c 111) a 112) b
113) b 114) c 115) b 116) a
117) b 118) c 119) b 120) b
121) a 122) b 123) d 124) d
125) a 126) d 127) c 128) a
129) d 130) d 131) b 132) c
133) d 134) b 135) d 136) c
137) c 138) a 139) d 140) a
141) c 142) a 143) a 144) c
145) c 146) c 147) c 148) b
149) b 150) d 151) a 152) d
153) c
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NEET BIOLOGY
REPRODUCTION IN ORGANISMS
: HINTS AND SOLUTIONS :
3 (a)
Bamboo is the monocarpic plant (which
reproduce once in their life time). They reproduce
once in 50-100 yrs after their birth and after
flowering they die
6 (a)
Asexual reproduction in plants called vegetative
reproduction. Rhizome, runner, sucker all are the
examples of asexual reproduction
7 (c)
Bodies involved in asexual reproduction
Conidia are non-motile gametes found singly or in
chain on the parent body, π.π., Penicillium
False Gemmule formation is the type of
reproduction in which the buds are formed with
in the parent body, π.π., Sponge
9 (a)
Juvenile phase is the phase of life span in which
growth of body and full development of
reproductive organ takes place. It is called
vegetative phase in plants
10 (d)
Very essential event in sexual reproduction is
fertilization and in fertilization the fusion of male
and female gametes takes place
11 (a)
Budding In this type of asexual reproduction the
daughter individual is formed on the small
outgrowth of parent body, π.π, Yeast, Hydra, etc
15 (a)
Self-fertilisation is very common phenomenon in
plants. This phenomenon takes place only when
there is the presence of bisexual flower
18 (c)
Hermaphrodite/bisexual/monoecious/homothalli
c term used when both the sexes are present in
same organism. Term βhermaphroditeβ is used in
case of animals. Bisexual and monoecious used in
both (animal/plant)
19 (d)
Male gametes are called antherozoids in case of
lower organism like fungi and algae and in higher
organism it is called sperm like mammals,
reptiles, etc.
24 (c)
Binary fission It is the mode of reproduction in
which the single organism divides into two parts,
i.e., Amoeba, Paramecium
27 (a)
Seasonal breeders which reproduced in the
favourable season only. Their reproductive
organs starts functioning due to seasonal changes
thus they have the specific time period in which
the reproduction takes place
οΏ½
οΏ½.π., Mammals (dog, cow, etc.)
Page| 14
30 (a)
True. When both the sexes are present on the
same organism called hermaphrodite, π.π.,
Earthworm, leech, etc
32 (c)
Ant, aphids, cockroaches are unisexual only
earthworm have both the sexes (hermaphrodite)
39 (b)
In the given diagram three figures are there first
figure indicate the fusion of male and female
gametes
Second figure indicate the zygote because there
are two nuclei visible in completely fused
condition
Third figure indicates the complete one cell after
fusion is over, all is there can be called new
individual
40 (d)
All examples shown below are, the examples of
vegetative reproduction
41 (c)
Gametogenesis Process of formation of gametes
(male and female) is called gametogenesis.
Gametes are the haploid reproducing cells
43 (d)
After forming the zygote it under goes successive
cleavage and becomes mass of cells. Cleavage is
considered as mitosis without resting phase.
As in nature in the process of mitosis the genetic
constitution remains the same hence, resulting all
cells have similar genetic constitution. Cleavage is
followed by cell differentiation processes like
gastrulation, etc., which finally gives rise to
different body parts
46 (a)
Large number of offsprings produced in case of
externally fertilized animals because there is no
direct protection, from the environment
47 (a)
The time period from birth till death is called life
span.
The life span is generally divided into four parts
(i) Juvenility Period of life span from birth till the
organism develops the capacity to reproduce
(ii) Maturity Reproduction begins and flourished
in this stage
(iii) Senescence or ageing Progressive detoriation
of the body is called ageing. Ageing ends in
senescence
(iv) Death It stopping of all vital activity of an
organism at senescence leads to death
48 (b)
Maturation stage
The time period from birth till death is called life
span.
The life span is generally divided into four parts
(i) Juvenility Period of life span from birth till the
organism develops the capacity to reproduce
(ii) Maturity Reproduction begins and flourished
in this stage
(iii) Senescence or ageing Progressive detoriation
of the body is called ageing. Ageing ends in
senescence
(iv) Death It stopping of all vital activity of an
organism at senescence leads to death
50 (c)
A-clearly indicate the homogametes or
isogametes because both gametes are identical
B-Clearly indicates that, it is not homogametes
because there is much size difference
C-Indicate the two well defined gametes which
are not similar, i.e., ovum (female) and sperm
(male)
52 (c)
Statement I It is incorrect. The correct sentence is
βlower groups of organisms have simple body
formsβ.
Statement II It says the organisms, which evolve
earlier reproduced by asexual mode of
reproduction because of their simpler body plans
Statement III It is wrong sexual reproduction is
common in higher organism
Statement IV It says that in complex organism or
organism, which evolve later have the complex
body plan and they reproduce by means of sexual
reproduction which is complex than the asexual
one
Page| 15
53 (d)
A-Potato, B-Ginger, C-Bryophylllum, D-Water
hyacinth, E-Agave
Name of
plants
Types of Reproduction
/Characteristics
Potato
Ginger
Agave
Bryophyllu
m
Water
hyacinth
Tuber
Rhizome
Bulbil
Leaf buds
Offset
54 (d)
Old age is the phase in life span which occur
before death and after maturity period.
In old age almost all of the vital processes starts
slowing down. Gamete formation also stops in old
age
56 (a)
Prokaryotes (bacteria) and Protista are single
celled organisms. Their mode of reproduction is
cell division. In them the parent body as a whole
constitute the reproductive unit and divided into
two by various mode. So, they are immortal
61 (d)
As we know oviparous individuals lay eggs with
white hard shell around it and this white hard
shell is made up of calcium
65 (a)
Zygote considered as the single cell with two
nuclei. Because zygote is the union of male and
female gametes, which are haploid
Two haploid cell fuse form diploid cell. Thatβs way
it considered as single cell and from zygote every
organism begin their life
67 (c)
Morphologically and genetically similar
organisms are called clones
These are produced through asexual reproduction
which is the type of reproduction where there is
the participation of only single organism
72 (c)
Sexual reproduction is characterized by genetic
recombination. Due to genetic recombination the
progeny is different from the parents.
In sexual reproduction the genetic material comes
from the two parents of same species. But in
asexual reproduction only one individual
participate to produce offspring
74 (b)
False Gemmule formation is the type of
reproduction in which the buds are formed with
in the parent body, π.π., Sponge
75 (a)
Strobilanthus kunthiana also called Neela Kuranji
in local language. It is found in Kerala,
Maharashtra, Tamil Nadu. It reproduce once in 12
yr
Last time it was reproduced in Sept-Oct, 2006 and
produced blue flower in massive quantity. It
attracted tourist because all of the area appeared
blue
76 (b)
False. Because in Hydra the common mode of
reproduction is bud formation which is the small
outgrowth attach to parent body externally
78 (d)
Irregular binary fission β Amoeba
Longitudinal binary fission β Euglena
Transverse binary fission β Paramecium
80 (a)
Participation of one individual
Morphologically and genetically similar
organisms are called clones
These are produced through asexual reproduction
which is the type of reproduction where there is
the participation of only single organism
81 (a)
Conidia are non-motile gametes found singly or in
chain on the parent body, π.π., Penicillium
Page| 16
82 (b)
Corms are the unbranched rounded underground
stems. They buds for daughter plants. Axillary
buds occur at places. Their base contains a
number of adventitious roots
84 (c)
Female gametes are called ovum in case of higher
organism. The term egg is also used.
Interchangeably Archegonia also used for female
gametes containing organs but in case of lower
organism, i.e., Bryophytes and pteridophytes
94 (a)
Reproduction is one of the fundamental processes
in which individual produces a young one
95 (c)
Water hyacinth consumes oxygen from water and
decreases its O2 content.
βTerror of Bengalβ is the aquatic plant (water
hyacinth) introduced in Bengal for its beautiful
leaves and flower. But it grows very faste and
consumes O2 from water.
Due to which lot of fish died. Thatβs why it was
called Terror of Bengal
97 (d)
A-indicate female cockroach because leaf like
structure of ovary is distinguished character of
female cockroach. B-plant body is thalloid and
sexes are separate indicates Marchantia
C-Male and female gametes on same plant so
monoecious or bisexual flower
98 (c)
Gamete mother cells are called gamete producing
cells. In these the meiotic cell division takes place.
Hence, they are also called meiocytes
100 (a)
Zoospore zoo-motile, sporeβminature gamete.
Generally, male gametes are motile. They are
commonly found in the fungi and animal kingdom
Sessile spore are generally female gametes. Here,
one must understand that zoospores are not
differentiated to male and female
101 (a)
As we know that oviparous individuals lay eggs
outside the body hence, further development
takes place outside.
But, the process of fertilization takes place inside
their body
105 (b)
Binary fission is the common mode of
reproduction in bacteria and Protista.
It may be of many types
Irregular binary fission β Amoeba
Longitudinal binary fission β Euglena
Transverse binary fission β Paramecium
107 (d)
Name of
plants
Types of Reproduction
/Characteristics
Potato
Ginger
Agave
Bryophyllu
m
Water
hyacinth
Tuber
Rhizome
Bulbil
Leaf buds
Offset
109 (b)
False. Staminate are the unisexual male flower/or
plant which produces the male gametes only
called staminate plant
110 (c)
Fishes are dioecious so no self – fertilisation.
Earthworm, liverfluke, leech all are
hermaphrodite but hermaphrodism is not
necessary to give rise to self – fertilisation. In
given options only liverfluke does self –
fertilisation
112 (b)
Page| 17
New organism without fertilization is called
parthenogenesis, π.π., Ant, bees, termites
113 (b)
In internal fertilization syngamy takes place
inside the body of female reproductive tract. It is
direct protection from the environment to the
developing progeny
114 (c)
βTerror of Bengalβ is the aquatic plant (water
hyacinth) introduced in Bengal for its beautiful
leaves and flower. But it grows very faste and
consumes O2 from water.
Due to which lot of fish died. Thatβs why it was
called Terror of Bengal
116 (a)
Generally, the oestrus cycle takes place in the
seasonal breeders. It is the cyclic change in the
activity of ovaries and accessory duct during
reproductive (seasonal) period
117 (b)
False. Pistillate are unisexual female plant. These
plant produce only female flower
119 (b)
Transfer of male gametes (pollen) to the
receptacle (stigma) of the female is called
pollination
Generally, the pollination takes place by various
means like air/ water / animals / insects, etc.
123 (d)
Production of plant by culturing the cells in
laboratory is called micropropagation
It is also called tissue culture. In this technique the
plants are genetically similar to parent one. Thatβs
why called somaclonal plants
125 (a)
Presence of diploid zygote is universal in all
sexually reproducing organism. Irrespective of
the fact that, the parents are haploid or diploid.
In haploid parent condition, the diploid zygote
undergoes meiosis and become haploid body
again, while in diploid organisms, the diploid
zygote changes to diploid individual after
undergoing mitosis
126 (d)
Heterothallic/dioecious/unisexual term used
when the sexes present on different organisms
called male and female
The archegonia and antheridia term used in case
of lower organism
127 (c)
In cell division the cell divides into two parts
having same genetic constituent. Only Monera and
Protista are the organisms, which are single celled
in five kingdom of classification.
Thatβs why cell division is the common mode of
reproduction in Monera and Protista
129 (d)
Sequential events in the sexual reproduction are
132 (c)
Syngamy and fertilization both the terms are used
interchangeably, for the fusion of male and female
gametes
135 (d)
Propagation by plant Tissue Culture
(micropropagation) includes propagation of
plants by culturing the cells, tissue, etc.
Initially the culturing of cells or tissue results in
the formation of an undifferentiated mass of cell
called callus, which differentiate to produce large
number of plantlets
136 (c)
In micropropagation (tissue culture) there is the
origin of an individual plant from few cells, so in
laboratory many plants could be propagated in
little time.
This technique basically used for the plants, which
are endangered
138 (a)
Embryogenesis refers to the development of
embryo from the zygote. During embryogenesis,
zygote undergoes cell division (mitosis) and cell
differentiation. Cell division of zygote is called
cleavage
139 (d)
All are correct
Strobilanthus kunthiana also called Neela Kuranji
in local language. It is found in Kerala,
Maharashtra, Tamil Nadu. It reproduce once in 12
yr
Last time it was reproduced in Sept-Oct, 2006 and
produced blue flower in massive quantity. It
Page| 18
attracted tourist because all of the area appeared
blue
141 (c)
Menstrual cycle is the periodic hormonal ovarian
change. It takes place in every month in the
primates Stopping of menstrual cycle is called
menopause
142 (a)
Irrespective of the fact whether plant is haploid or
diploid, it has haploid gametes
In mitotic cell division the chromosome number
remains the same. In meiotic cell division the
chromosomes number becomes half
146 (c)
Syngamy (fertilisation) fusion of male and female
gametes is called syngamy or fertilization. It is of
two types
(i) External Fertilisation When the syngamy takes
place in the external medium. Generally, the
external medium is water, π.π., Amphibians,
fishes
(ii) Internal Fertilisation When the syngamy takes
place inside the female body, π.π., Reptiles, bird,
mammals
152 (d)
Asexual reproduction is common in single celled
organisms, because in asexual reproduction
mitotic cell division takes place which is quick and
simple as compared to meiosis, so asexual
reproduction is the most common mode of
reproduction in the given options
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NEET MCQs Inheritance and Variation [Free PDF Download]
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NEET MCQs Inheritance and Variation – Sample
- A haemophilic woman marries a normal man, then
a) All the children will be normal b) All the sons will be haemophilic
c) All the girls will be haemophilic d) Half girls will be haemophilic - Disorder inherited as Mendelβs law of inheritance called
a) Mendelian disorder b) Chromosomal disorder
c) Maternal inheritance d) Polygenic inheritance - The term βgeneβ was coined by
a) Avery b) Bateson c) Johanssen d) Mendel - The phenotypic ratio in the πΉ2 gereration of dihybrid cross, is
a) 9 : 3 : 3 : 1 b) 1 : 2 : 2 : 4 : 1 : 2 : 1 : 2 : 1
c) 7 : 1 : 1 : 7 d) 12 : 8 : 4 - Chromosome is made up of
a) DNA +pectin b) RNA +DNA c) DNA +histone d) Only histone - Select the incorrect statemant from the following.
a) Linkage is an exception to the principle of
independent assortment in heredity
b) Galactosemia is an inborn error of metabolism
c) Small population size result in random genetic
drift in a population
d) Baldness is a sex-limited trait - A pure tall and a pure dwarf plant were crossed to produced offsprings. Offsprings were self crossed, then
find out the ratio between true breeding tall to true breeding dwarf?
a) 1 : 1 b) 3 : 1 c) 2 : 1 d) 1 : 2 : 1 - Exposure of X-rays enhances the frequency of
a) Linkage b) Crossing over
c) Pairing of chromosome d) Segregation - A self-fertilizing trihybrid plant forms
a) 8 different gametes and 64 different zygotes b) 4 different gametes and 16 different zygotes
c) 8 different gametes and 16 different zygotes d) 8 different gametes and 32 different zygotes - Genotype is the
a) Genetic constitution b) Genetic constitution of the phenotype
c) Trait expressed d) Expressed genes - Failure of cytokinesis after β¦Aβ¦ stage of cell division results in an increase in a whole set of chromosomes
in an organism called β¦Bβ¦
a) A-prophase, B-polyploidy b) A-metaphase, B-polyploidy
c) A-anaphase, B-polyploidy d) A-telophase, B-polyploidy - In previous question find out total seeds (plants) having round seed texture
a) 12 b) 10 c) 9 d) 11 - The ratio 1 : 1 : 1 : 1 is obtained from a cross between the parents
a) RRYYΓrryy b) RRYYΓrryy c) RRYYΓRryy d) RrYyΓrryy - Which of the following terms represent a pair of contrasting characters?
a) Homozygous b) Heterozygous c) Allelomorphs d) Codominant genes
NEET MCQs Inheritance and Variation – Page| 2
- Harmful mutation does not get eliminated from the gene pool because they are mainly
a) Dominant, which have beneficial effect on population and carried by heterozygous individuals
b) Dominant, which have beneficial effect on population and carried by homozygous individuals
c) Carried from one generation to another generation through autosomal chromosomes
d) They show genetic drift - Incomplete linkage is β¦Aβ¦ . Complete linkage is β¦Bβ¦ . Choose correct option for A and B
a) A-common, B-rare b) A-rare, B-common
c) A-impracticle, B-practicle d) A-practicle, B-impracticle - Mendelism was rediscovered by
I. Morgan
II. De Vries
III. Correns
IV. Tschermark
Choose the correct option
a) I, III and IV b) I, II, III and IV c) II, III and IV d) I, II and III - In gynandromorphs,
a) Some cells of body contain XX and some cells with genotype XY
b) All cells have XX genotype
c) All cells have XY genotype
d) All cells with genotype XXY - Example of interagenic gene interaction is/are
a) Incomplete dominance b) Codominant
c) Multiple alleles d) All of the above - If a cross between two individuals produces offspringe with 50% dominant character (A) and 50%
recessive character (a),then the genotypes of parents are
a) Sex linked genes b) Pseudoallelic genes
c) Intermediate inheritance d) Dominant and recessive genes - Which is correct about traits choosen by Mendel for his experiment on pea plant?
a) Terminal pod was dominant b) Constricted pod was dominant
c) Green coloured pod was dominant d) Tall plants were recessive - Codominance is found in
a) Plants b) Animal c) Both (a) and (b) d) Prokaryote - During Mendelβs investigation, it was first time that β¦Aβ¦ and β¦Bβ¦ were applied in biology. Here A and B
refers to
a) A-statistical analysis; B-mathematical logic
b) A-statistical analysis; B-physical logic
c) A-statistical analysis; B-chemistry logic
d) A-statistical analysis; B-simple logic - The chromosomal denotation for heterogametic female and homogametic male are
a) ZW and ZZ b) ZO-ZZ c) XX-XO d) Both (a) and (b) - Pure tall plants are crossed with pure dwarf plants. In the F1-generation, all plants were tall. These tall
plants of F1-generation were selfed and the ratio of tall to dwarf plants obtained was 3: 1. This is called
a) Dominance b) Inheritance c) Codominance d) heredity - The best method to determine the homozygosity and heterozygosity of an individual is
a) Self-fertilisation b) Back cross c) Test cross d) Inbreeding - A medical technician, while observing a human blood smear under the microscope notes the presence of a
Barr body close to the nuclear membrane in the WBC. This indicates that the person under investigation is
a
a) Colourblind b) Haemophilic c) Normal female d) Normal male - Find out π΄,π΅ and πΆ in the diagram given below in
NEET MCQs: Inheritance & Variation – Page| 3
a) A-Male, B-Female, C-Gametes b) A-Male, B-Female, C-Sperm
c) A-Female, B-Male, C-Gametes d) A-Gametes, B-Male, C-Female
- In Turnerβs syndrome
a) Female is fertile b) Male is fertile c) Female is sterile d) Male is sterile - The most likely reason for the development of resistance against pesticides in insect damaging a crop is
a) Random mutations b) Genetic recombination
c) Directed mutations d) Acquired heritable changes - Lampbrush chromosomes sre seen in
a) Interphase b) Zygotene c) Diplotene d) metaphase - In case of incomplete dominance, what will be the phenotypic ratio of πΉ2generation?
a) Histones b) Hydrocarbons c) Polynucleotides d) Lipoproteins - Examples of dissimilar sex chromosomes are given below
I. XX β XY β I
II. XX β XO β II
I and II in the above statement can be
I II a) Man and most
insect
Cockroach and
roundworms
b) Cockroach and
roundworms
Man and most
insect
c) Butterfly Fishes
d) Bird Reptiles
- Mutations, which alter nucleotide sequence within a gene are
a) Frameshift mutation b) Base pair substitutions
c) Both (a) and (b) d) None of these - The πΉ1generation has all tall, and πΉ2ratio is 3 : 1, it proves
a) Law of dominance b) Independent assortment
c) Law of segregation d) linkage - Mendelβs law were true for situation in which
a) Alleles are affected by their environment b) Alleles shows complete dominance
c) Alleles of a gene alter the affect of a different gene d) A given character is determined by more than one
gene - Blood group-O has
a) No antibodies b) No antigens c) a or b antibodies d) A and B antigens - Wilson detected the colour blindness disease in
a) 1921 b) 1911 c) 1912 d) 1910 - In a dihybrid cross between RRYY and rryy parents, the number of RrYy genotypes in πΉ2generation will be
a) 4 b) 3 c) 2 d) 1 - If a cross between two individuals produces offspringe with 50% dominant character (A) and 50%
recessive character (a),then the genotypes of parents are
a) Genic interactions controlling a character b) Multiple genes controlling a character
c) Expression of many characters by a single gene d) Alternative forms of a gene at a given locus - A women with albinic father marries an albinic man.the proportion of her progeny is
a) 2 normal : 1 albinic b) All normal
c) All albinic d) 1 normal : 1 albinic
NEET MCQs: Inheritance & Variation – Page| 4
- When one sex chromosome is lacking in female and males are homogametic, in that condition, the sex
chromosomal representation is
a) ZO-ZZ b) XY-XX c) XX-XO d) ZW-ZZ - Some individuals with blood group βA may inherit the genes for blonde hair, while other individuals with
blood group β A may the gene for brown hair. This can be best explained by the principle of
a) Dominance b) Multiple alleles
c) Independent assortment d) Incomplete dominance - In bugs and cockroaches, the sex determination takes place by
a) XX and XO chromosomes b) XX and XY chromosomes
c) ZZ-ZW chromosomes d) ZO-ZZ chromosomes - The two β¦Aβ¦ separate and pass into two daughter nuclei and cells during mitosis. Similarly, each β¦Bβ¦
replicates, with one pair passing into each daughter cell during mitosis. This maintains the similar β¦Cβ¦ of
all the cells.
Find out correct option for A, B and C
a) A-chromatid, B-allele pair, C-morphology b) A-chromatid, B-allele pair, C-genetic composition
c) A-organ, B-organ pair, C-individuality d) A-unlinked gene, B-linked gene, C-morphology - The shape of chromosome is determined by
a) Centrosome b) Centromere c) Chromomere d) telomere - Mendel was a
a) Austrian biology teacher b) Austrian monk
c) Austrian scientist d) Austrian mathematician - Who clearly proved and define linkage?
a) Morgan b) Castle c) Bateson d) Punnett - Improvement of human race through hereditary qualities is called
a) Euthenics b) Human heredity c) Human demography d) Eugenics - Test cross involves
a) Crossing between two genotypes with recessive trait
b) Crossing between two F1-hybrids
c) Crossing the F1-hybrid with a double recessive genotype
d) Crossing between two genotypes with dominant trait - When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the
resulting seed is
a) Tetraploidy b) Pentaploidy c) Diploidy d) Triploidy - Colour blindness is
a) Sex-linked recessive disease
b) Sex-linked dominant disease
c) Autosomal dominant disease
d) Autosomal recessive disease - A condition, where a certain gene is present in only a single copy in a diploid cell, is called
a) Four different types of gametes produed by the πΉ1
dihybrid b) Homozygous condition of the πΉ1-dihybrid
c) Four different types of πΉ1-dihybrids d) Four different types of gametes produed by the
οΏ½
οΏ½1-parent - If the blood group of a child is A and of mother is B, then the genotype of mother and father may be
a) BBΓAA b) ABΓAB c) BOΓOO d) BOΓAO - symbol in pedigree analysis represents
a) Still birth b) Still death c) Still carrier d) Still mating - Which amino acids are present in histones?
a) Lysine and histidine b) Valine and histidine
NEET MCQs: Inheritance & Variation – Page| 5
c) Arginine and lysine d) Arginine and histidine
- Monosomic trisomy are represented as
a) 2πβ1+1 b) 2πβ1β1 c) 2πβ1 d) 2π+1+1 - Which is a sex-influenced disease?
a) Baldness in male b) Haemophilia
c) Xeroderma pigmentosa d) Downβs syndrome - Thalassaemia is
a) Autosomal recessive disease b) Autosomal dominant disease
c) Sex-linked dominant disease d) Sex-linked recessive disease - Mutation is phenomena which results in alternation of
a) Sequence b) Carbohydrates c) Proteins d) Fat - A man with normal vision whose father was colourblind marries with women whose father was also
colourblind. Suppose their first child is daughter then what are the chances of this child to be colourblind?
a) 100% b) 25% c) 50% d) 0% - Gamete mother cells of the chromosome 44 + XY suffers from non-disjunction at first meiotic division.
Which of the following set of gametes would result?
a) 22 + XX, 22 + XY, and 22, 22 b) 22 + XY, 22 + XY, and 22, 22
c) 22 + X, 22 + Y, and 22 + Y, 22 d) 22 + X, 22 + XY, and 22 + Y, 22 + Y - Law of Mendel, which is not completely applicable is?
a) Codominance b) Law of segregation
c) Law of independent assortment d) Law of dominance - Low pitched voice, beared and moustaches, belong to the
a) Sex limited traits b) Sex linked trait c) Nullisomic traits d) Sex influenced traits - Multiple allele can be manifested only when there is the study of
a) Individual organism b) Genus c) Population d) Phylum - πππππ‘ππππ π π¦ππ£ππ π‘πππ flowers only during long days and π.π‘πππππ’π flowers only during short days, if
raised in the laboratory under different photoperiods, they can be induced to flower at the same time and
can be cross fertilized to produce self-fertile offspring. What is the best reason for considering N. sylvestris
and N. tobaccum to be separate species?
a) They are physiologically distinct b) They are morphologically distinct
c) They cannot interbreed in nature d) They are reproductively distinct - The following diagram shows two types of chromosomal mutations
Give the name or type of mutation in respect to A and B
a) A-Duplication, B-Substitution b) A-Duplication, B-Deletion
c) A-Inversion, B-Deletion d) A-Inversion, B-Substitution
- How many different kinds of gametes will be produced by a plant having the genotype AABbCC?
a) Three b) Four c) Nine d) Two - Downβs syndrome and Turnerβs syndrome occur in human beings due to
a) Monosomic and nullisomic conditions respectively b) Monosomic and trisomic conditions respectively
c) Trisomic and monosomic conditions respectively d) Trisomic and tetrasomic conditions respectively - What are all the chances of colourblind daughters of a normal man marrying normal women whose father
was colourblind?
a) All sons are normal and all daughters are
colourblind
b) Both the sons and daughters are phenotypically
normal
NEET MCQs: Inheritance & Variation – Page| 6
c) All the sons are colourblind and all daughters are
normal
d) 50% sons are colourblind and all daughters are
phenotypically normal
- In males, pattern baldness is related to both autosomal genes as well as excessive secretion of
a) Oestrogen b) Growth hormone c) Testosterone d) Inhibits - Which of these is not a Mendelian disorder?
a) Cystic fibrosis b) Sickle-cell anaemia c) Colourblindness d) Turnerβs syndrome - Which of the following is not true of haemophilia?
a) Royal disease b) Bleederβs disease
c) X-linked disorder d) Y-linked disorder - If heterozygous dominant (tT) crossed with homozygous dwarf plant, then the percentage of progeny
having dwarf character is
a) 60% b) 40% c) 50% d) 70% - Mutations are generally induced by means of
a) πΌβπππ¦π b) Ξ²βπππ¦π c) πΎβπππ¦π d) UV radiations - Two crosses between the same pair of genotypes or phenotypes, in which the sources of the gametes are
reversed in one cross, is known as
a) Dihybrid cross b) Reverse cross c) Test cross d) Reciprocal cross - A hereditary, disease, which is never passed on from father to son is
a) X-chromosomal linked disease b) Autosomal linked disease
c) Y-chromosomal linked disease d) None of the above - Bateson used the term coupling and repulsion for linkage and crossing over. Choice the correct coupling
and repulsion combination
Coupling Repulsion a) AABB, aabb AAbb, aaBB
b) AABB, aabb AABB, AAbb
c) AAbb, aaBB AaBb, aabb
d) aaBB, aabb AABB, aabb
- In blood group typing in human, if an allele contributed by one parent is IAand an allele contributed by the
other parent is i, the resulting blood group of the offspring will be
a) A b) B c) AB d) O - A person having 45 chromosomes and Y-chromosome absent. Is suffering from
a) Downβs syndrome b) Klinefelterβs syndrome
c) Turnerβs syndrome d) gynandromorph - Linkage and crossing over are
a) Same phenomena b) Different phenomena
c) Opposite phenomena d) Identical phenomena - The modern concept of gene is
a) A segment of DNA, capable of crossing over b) Functional unit of DNA
c) A segment of RNA d) A segment of chromosome - Females in haplodiploidy sex determination are
a) N b) 2n c) 1
2
n d) 3n - Using imprints from a plate with complete medium and carrying bacterial colonies, you can select
streptomycin resistant mutants and prove that such mutations do not originate as adaptation. These
imprints need to be used
a) Only on plates with streptomycin b) On plates with minimal medium
c) Only on plates without streptomycin d) On plates with and without streptomycin - Phenylketonuria, Huntingtonβs disease and sickle cell anaemia are caused respectively due to disorders
associated with
a) Chromosome-7, chromosome-11 and chromosome-12
b) Chromosome-11, Chromosome-4 chromosome-12
c) Chromosome-7, chromosome-12 and chromosome-11
d) Chromosome-12, chromosome-4 and chromosome-11
Page| 7
- The arrangement of genes on chromosome is
a) Linear b) Oviod c) Diffused d) Spiral - When two genetic loci produce identical phenotypes in πππ and π‘ππππ position, they are considered to be
a) Pseudoalleles b) Multiple alleles
c) The part of same gene d) Different genes - Which of the following matches correctly?
a) Factor βII – Thromboplastin b) Factor βIII – Prothrombin
c) Factor βVIII – Antihaemophilic globulin d) Factor βXII – Haemophilic - The longest chromosomes is seen in
a) Allium b) Lilium c) Trillium d) Zea mays - Mendel observed that β¦.. generation shows always phenotype of dominant parent
a) F4 b) F2 c) F1 d) F0 - β¦Aβ¦ genes are those which occurs on the same chromosome and β¦Bβ¦ genes are those, which are present
on different chromosome.
Choose correct choice for A and B
a) A-linked; B-unlinked gene b) A-unlinked; B-linked
c) A-identical; B-non-identical d) A-non-identical; B-identical - Allelic sequence variations where more than one variant (allele) at a locus in a human population with a
frequency greater than 0.01 is refered to as
a) Incomplete dominance b) Multiple allelism
c) SNP d) DNA polymorphism - The possibility of a female becoming a haemophilia is β¦Aβ¦ rare because mother of such a female has to be
at least β¦Bβ¦ and the father should be β¦Cβ¦
Choose the correct option for A, B and C
a) A-extremely, B-carrier, C-haemophilic
b) A-extremely, B-carrier, C-carrier
c) A-extremely, B-haemophilic, C-carrier
d) A-extremely, B-haemophilic, C-haemophilic - If the foetus is Rh+ and mother is Rhβ, then
a) Foetus will transmit antigen to mother blood
b) Foetus will transmit antibody to mother blood
c) Foetus is attacked by antibodies to mother blood
d) Foetus is attacked by antigen to mother blood - The most popularly known blood grouping is the ABO grouping. It is named ABO and not ABC, because βOβ
in it refers to having
a) Other antigens besides A and B on RBCs b) Over dominance of this type on the genes for A
and B types
c) One antibody onlyβeither anti-a or antiβb on the
RBCs
d) No antigens A and B on RBCs - Alleles are
a) Alternate forms of a gene b) Homologous chromosome
c) Pair of sex chromosome d) None of the above - Telomere repetitive DNA sequences control the function of eukaryotic chromosomes because they
a) Act as replicons b) Are RNA transcription initiator
c) Help chromosome pairing d) Prevent chromosome loss - Genotypic and phenotypic ratios remains the same in
a) Sex-linked genes b) Pseudoallelic genes
c) Intermediate inheritance d) Dominance and recessive genes - Mendelian disorder may be of
a) Recessive b) Dominant c) Both (a) and (b) d) Canβt be determined
NEET MCQs: Inheritance & Variation Page| 8
- Sickle βcell anaemia has not been eliminated from the African population because it
a) Is controlled by recessive genes b) Is not a fatal disease
c) Provides immunity against malaria d) Is controlled by dominant genes - A condition characterized by not having an exact number of chromosomes in a multiple of haploid set is
called
a) Polyploidy b) Synploidy c) aneuploidy d) None of these - Choose correct option for π΄,π΅,πΆ and π· a) A-tt, B-TT, C-TT, D-TT b) A-Tt, B-Tt, C-Tt, D-Tt
c) A-TT, B-TT, C-Tt, D-TT d) A-Tt, B-Tt, C-Tt, D-TT - When a cross is conducted between black feathered hen and a white feathered cock, blue feathered fowls
are formed. When these fowls are allowed for interbreeding, in F2- generation, there are 20 blue fowls.
What would be the number of black and white fowls?
a) Black 20, white 10 b) Black 20, white 20 c) Black 10, white 10 d) Black 10, white 20 - Chromosomes are made up of
a) DNA are protein b) RNA and DNA c) DNA and histone d) Only histones - In pedigree analysis, the square, blackened and horizontal lines represents
a) Female, healthy individual, parents b) Female, affected individual, parents
c) Male, affected individual, parents d) Male, affected individual, progeny - Following pedigree chart shows a) Character is carried by Y-chromosome b) Character is sex-linked recessive
c) Character is sex-linked dominant d) Character is recessive autosomal - Mr. Sidd is suffering from hypertrichosis and phenylketonuria. His father is heterozygous for
phenylketonuria. The probability of Siddβs sperm having one recessive autosomal allele and holandric
gene is
a) 1
2 b) 1
8 c) 1
10 d) 1
4 - F3-generation is obtained by
a) Selfing of F1 b) Selfing of F2 c) Crossing of F1 and F2 d) None of these - In which one of the following, complementary gene interaction rato of 9 : 7 is observed?
a) Fruit shape in Shepherdβs purse b) Coat colour in mouse
c) Feather colour in fowl d) Flower colour in pea - Starch synthesis gene in pea plant is the example of
a) Single gene produce more than one effects
b) Multiple genes produce more than one effects
c) Two genes produce more than one effects
d) Multiple genes produce less than one effects - In π·πππ ππβπππ , the sex is determined by
a) The ratio of pairs of X-chromosomes to the pairs of autosomes
b) Whether the egg is fertilized or develops parthenogenetically
NEET MCQs: Inheritance & Variation Page| 9
c) The ratio of number of X-chromosomes to the set of autosomes
d) X and Y-chromosomes
- The 1 : 2 : 1 ratio with the pink flower in the F2-generation indicate the phenomenon of
a) Dominance b) Codominance
c) Incomplete dominance d) Segregation - Sexual reproducation leads to
a) Genetic recombination b) Polyploidy
c) Aneuploidy d) Euploidy - Husband has blood group-A and wife has blood group-B. What is the blood group of children?
a) A b) B c) AB d) A, B, AB and O - Study the following figure and find out the most probable position at which the crossing over takes place a) w and W b) X and y c) y and Z d) w and z
- Given diagram shows certain type of traits in human. Which one of the following option could be an
example of this pattern? a) Haemophilia b) Anaemia c) Phenylketonuria d) Thalassaemia - In case of incomplete dominance, what will be the phenotypic ratio of πΉ2generation?
a) 3 : 1 b) 1 : 2 : 1 c) 1 : 1 : 1 : 1 d) 2 : 2 - Haemophilia, a X-linked recessive disease is caused due to deficiency of
a) Blood plasma and vitaminβK b) Blood platelets and haemoglobin
c) Lack of clotting material and vitamin-K d) All of the above - All of this obeys Mendelβs laws except
a) Codominance b) Independent assortment
c) Dominance d) Purity of gametes - in Ξ²-thalassaemia, the affected chromosome is
a) 16th b) 14th c) 13th d) 19th - In pea plants, yellow seeds are dominant to green. If a heterozygous yellow seeded plant is crossed with a
green seeded plant, what ratio of yellow and green seeded plants would you expect in πΉ1generation?
a) 50 : 50 b) 9 : 1 c) 1 : 3 d) 3 : 1 - Who was fly men of genetics?
a) Sutton b) Pasteur c) Robert Hooke d) TH Morgan - Mendelβs contribution for genetic inheritance was
a) The idea that genes are found on chromosomes
b) Providing a mechanism that explains patterns of inheritance
c) Describing how genes are influenced by the environment
d) Determining that the information contained in DNA codes for proteins - The genotypic ratio of a monohybrid cross in F2-generation is
NEET MCQs: Inheritance & Variation Page| 10
a) 3 : 1 b) 1 : 2 : 1 c) 2 : 1 : 1 d) 9 : 3 : 3 : 1
- Baldness is more common in men than in woman. It could be explained on the basis that
a) Genes of baldness are located on X-chromosomes only
b) Baldness genes are located on Y-chromosomes
c) Genes of baldness are autosomal but influenced by androgens
d) None of the above - How many pairs of contrasting characters in pea pod were chosen by Mendel?
a) 3 b) 5 c) 7 d) 9 - A mutagen pollutant is
a) Organophosphates b) Resins
c) Chlorinated hydrocarbons d) Nitrogen oxides - Both chromosome and gene (Mendelian factors) whether dominant or recessive are transmitted from
generation to generation in which form
a) Changed b) Unaltered form c) Altered form d) Disintegrated - Pedigree analysis is very important in human beings because
a) It helps genetic counselers to avoid disorders
b) It shows origin of traits
c) It shows the flow of traits in family
d) All of the above - Genes when present in homozygous condition results in non β viable progeny, the factor responsible for
such conditions are
a) Polygenes b) Linked genes c) Lethal genes d) Epistatic genes - Turnerβs syndrome caused due to the absence of
a) One X-chromosome (44 with XO) b) One Y-chromosome
c) One X-and Y-chromosome d) Two X-chromosome - The recessive genes located on X-chromosome in humans are always
a) Lethal b) Sub-lethal c) Expressed in males d) Expressed in females - Strength of the linkage between the two genes is
a) Proportionate to the distance between them
b) Inversely proportionate to the distance between them
c) Depend on the chromosomes
d) Depend upon the size of chromosomes - Fruitfly is excellent model for genetics because of
I. Small life cycle (two week)
II. Can be feed on simple synthesis medium
III. Single mating produce large number of progeny
IV. Clear differentiation of sexes
V. Many heredity variation can be seen with low power microscopes
Choose the correct option
a) I, II and III b) III, IV and V c) I, IV and V d) All of these - In Guinea pigs, black short hair (BBSS) is dominant over white long hair (bbss). During a dihybrid cross,
the πΉ2-generation individuals with genotypes BBSS, BbSS, BBSs and BbSs are in the ratio of
a) 9 : 3 : 3 : 1 b) 4 : 2 : 1 : 2 c) 1 : 2 : 1 : 2 d) 1 : 2 : 2 : 4 - When both parents are of blood type AB, they can have children with
a) A, B, AB and O blood types b) A, B, and AB blood types
c) A and B blood types d) A, B and O blood types - Test cross is
a) Recessive F1-plant crosses with dominant F2-plant
b) Recessive F2-plant crosses with dominant F3-plant
c) Dominant F2-plant crosses with recessive parent plants
d) Dominant F2-plant crosses with heterozygous parent plants
Page| 11
- The phenomenon of a single gene regulating several phenotypes is called
a) Multiple allelism b) epistasis
c) Incomplete dominance d) Pleiotropism - If two pea plants having red (dominant) coloured flowers with unknown genotypes are crossed, 75% of
the flowers with unknown genotypes are crossed, 75% of the flowers are red and 25% are white. The
genotypic constitution of the parents having red coloured flowers will be
a) Both homozygous b) One homozygous and other heterozygous
c) Both heterozygous d) Both hemizygous - A woman has a haemophilic son and three normal children. Her genotype and that of her husband with
respect to this gene would be
a) XX and XhY b) XhXh and XhY c) XhXh and XY d) XhX and XY - The proportion of plants that were dwarf and tall in F2- generation ofo Mendel experiment
a) 1
4th and 3
4th b) 3
4th and 1
4th c) 2
3rd and 1
3rd d) 1
3rd and 4
3rd - Night blindness is
a) Genetic disease b) Nutritional deficiency disease
c) Generally found in male d) Generally found in female - Two genes R and Y are located very close on the chromosomal linkage map of maize plant. When RRYY
and rryy genotypes are hybridized, then πΉ2-segregation wii show
a) 1 : 2 : 1 b) 3 : 1 c) 9 : 3 : 3 : 1 d) 1 : 1 : 1 - Who argued that pairing and separation of chromosomes would lead to the segregation of a pair of factor
they carried?
a) Sutton b) Boveri c) Both (a) and (b) d) Morgan - Sex chromosomes of male are
a) Homozygous b) Heterozygous c) Hemizygous d) autosomes - Trisomy of which chromosome is involved in Downβs syndrome?
a) 15th b) 21st c) 20th d) 19th - Which of the following symbols are used for representing chromosome of birds?
a) ZZ-ZW b) XX-XY c) XO-XX d) ZZ-WW - Sudden and heritable change in a character of an organism is called
a) Mutation b) Heterosis c) Inbreeding d) selection - Heterozygous purple flower is crossed with recessive white flower. The progeny has the ratio
a) All purple b) All white
c) 50% purple, 50% white d) 75% purple, 25% white - The Mendel crossed true breeding tall and dwarf plant varieties in his experiment. The tall character was
dominant and recessive character was dwarf. The recessive character was appeared in
a) F1 b) F2 c) F3 d) F2 and F3 - Night blindness can be corrected by giving vitamin- β¦Aβ¦ but colour blindness canβt be cured because it is
β¦Bβ¦ disease.
Choose the correct option for A and B
a) A-A; B-genetic b) A-B; B-autosomal c) A-C; B-non-genetic d) A-D; B-genetic - Heredity is
a) Transmission of characters b) Mixing of characters
c) Blending of inheritance d) Deleting of characters - Which of these statements about Huntingtonβs disease is true?
a) Genetic tests to detect the presence of the allele responsible for Huntingtonβs disease do not exist at this
time
b) The onset of Huntingtonβs disease is typically between birth and three years of age
c) There is currently no effective treatment of Huntingtonβs disease
d) Huntingtonβs disease is caused by the expression of a recessive allele
Page| 12
- Centromere is required for
a) Transcription b) Crossing over
c) Cytoplasmic cleavage d) Movement of chromosomes towards poles - Which of the following condition in humans is correctly matched with its chromosomal
abnormality/linkage?
a) Klinefelterβs syndrome β44 autosomes + XXY b) Colour blindness βY- linked
c) Erythroblastosis foetalis βX- linked d) Downβ s syndrome β 44 autosomes+ XO - Rrrr progeny : Red (dominant) flowered heterozygous crossed with white flower
a) 350βredβΆ350βwhite b) 450βredβΆ250βwhite
c) 380βredβΆ250βwhite d) None of these - A hereditary disease which is never passed on form father to son is
a) X- chromosomal linked disease b) Autosomal linked disease
c) Y- chromosomal linked disease d) None of the above - A man with blood group-B marries a woman with blood-A and their first child is having blood group-B.
What is the genotype of child?
a) IaIb b) IaIo c) IbIo d) IbIb - Linked gene are present on
a) Same chromosome b) Different chromosome
c) Heterologous chromosome d) Paired chromosome - The structure that become double in synthesis phase of cell division is/are
a) RNA b) Centriole c) DNA d) None of these - Genetics is the branch of biology which deals with
a) Variation b) Inheritance c) Both (a) and (b) d) Study of characters - Giant chromosomes are found inside
a) nucleus of man b) oocytes of frog
c) salivary glands of silk moth d) salivary glands of Drosophila - Who is known as father of physiological genetics or father of biochemical genetics?
a) Slatyer b) Charles Elton c) Taylor d) Archibald Garrod - The graphical representation to calculate the probability of all possible genotypes of offspring in a genetic
cross, is called
a) Pedigree analysis b) Karyotype c) Punnett square d) Chromosome map - Rh factor can produce disease
a) AIDS b) Turnerβs syndrome
c) Erythroblastosis foetalis d) Sickle-cell anaemia - To determine heterozygousity of a cross, one has to perform
a) Back cross b) Reciproacal cross c) Test cross d) Any of these - Which of the following type of mutation involves the reverse order of genes in a chromosome?
a) Deletion b) Duplication
c) Inversion d) Reciprocal translocation - The chromosomal number in the meiocytes of housefly is
a) 8 b) 12 c) 21 d) 23 - The alternate forms of a gene is called
a) Recessive character b) Dominant character
c) Alleles d) Alternative gene - Haemophilia is related to
a) Albinism b) Sickle-cell anaemia c) Colour blindness d) thalassemia - Identify a Mendelian disorder from the following.
a) Downβs syndrome b) Turnerβs syndrome
Page| 13
c) Phenylketonuria d) Klinefelterβs syndrome
- When a tall plant with round seeds (TTRR) crossed with a dwarf plant with wrinkled seeds (ttrr), the πΉ1
generation consists of tall plants with round seeds. What would be the proportion of dwarf plant with
wrinkled seeds in πΉ1-generation?
a) 1
4 b) 1
16 c) 0 d) 1
2 - The term βGeneticsβ was proposed by
a) Mendel b) Bateson c) Motgan d) Johanssen - Sex chromosomes are also known as
a) Autosomes b) Allosomes c) Genome d) karyotype - Mendel obtained recessive character in F2 by β¦Aβ¦ the β¦Bβ¦ plants. Here π΄ and π΅ refers to
a) A-self-pollinating; BβF1 b) A-self-pollinating; BβF2
c) A-cross-pollinating; BβF1 d) A-cross-pollinating; BβF2 - In a family father had a trait but mother did not. All their sons and daughter had this trait. The same trait
was found in some grand daughters, through daughter were married to the normal persons.
Choose the correct pedigree chart for the condition
a)
b)
c)
d)
- If genes of an allelic pair are not-same. This condition is called
a) Homozygous b) Heterozygous c) Diallelic d) Polyallelic - Which type of pollination method was adopted by Mendel in his experiment?
a) Artificial b) Cross pollination c) Natural d) Both (a) and (b) - Select the correct statement from the ones given below with respect to dihybrid cross.
a) Tightly linked genes on the same chromosome
show higher recombinations
b) Genes far apart on the same chromosome show
very few recombinations
c) Genes loosely linked on the same chromosome
show similar recombinations as the tightly linked
ones
d) Tightly linked genes on the same chromosome
show very few recombinations - Grain colour in wheat is determined by three pairs of polygene. Following the cross
AABBCC(dark colour)Γaabbcc(light colour) , in πΉ2 generation. What proportion of the progeny is likely to
resemble either parent?
a) Half b) Less than 5 per cent c) One βthird d) None of these - Chromosomal abbreviation commonly found in the
a) Cancer cells b) Normal cells c) Healthy cells d) Autosomal cells - In short horned cattle, genes for red( R) and white( r) coat colour occur. Cross between red (RR) and
white (rr) produced (Rr) roan. This is an example of
a) Incomplete dominance b) Codominance
c) Complementary genes d) Epistasis - Female is haemophilic definitely if
a) Mother is carrier b) Father is carrier
c) Father is affected d) Both mother and father affected
Page| 14
- Polyploidy leads to rapid formation of new species because of
a) Isolation b) Development of multiple sets of chromosomes
c) Mutation d) Genetic recombination - Law of segregation is also called law of
a) Probability b) Purity of gametes
c) Independence of gametes d) Punnett hypothesis - Test cross is a cross between
a) HybridΓDominant parent b) HybridΓRecessive parent
c) HybridΓHybrid parent d) Two distantly related species - XX and XY chromosomal sex determination, females are
a) Homogametic b) Heterogametic
c) Can not determine d) All of the above - Heterogametic male condition does not occur in
a) Birds b) Humans c) Drosophila d) Honey bee - In a typical Mendelian cross which is a dihybrid cross, one parent is homozygous for both dominant traits
and another parent is homozygous for both recessive traits. In the πΉ2 generation, both parental
combinations and recombinations appear. The phenotypic ratio of parental combinations to
recombinations, is
a) 10:6 b) 12:4 c) 9:7 d) 15:1 - The genotype of a plant showing the dominant phenotype can by
a) Test cross b) Dihybrid cross c) Pedigree analysis d) Back cross - If a man who is colourblind marries a women, who is pure normal for colour vision, the chances of their
sons have colour blindness is
a) 100% b) 50:50 c) 0% d) 75 : 25 - When a tall pea plant (TT) is crossed with dwarf plant (tt) what will be the F2-generation?
a) All tall plants b) All dwarf plants
c) Both tall and dwarf plants in 1 : 1 ratio d) Both tall and dwarf plants in 3 : 1 ratio - Broadly the genetic disorders may be classified in β¦Aβ¦ group Mendelian disorder and β¦Bβ¦ disorders.
Mendelian disorder are mainly determined by β¦Cβ¦ in single gene.
Choose the correct option for A, B and C
a) A-two, B-chromosomal, C-genetic b) A-two, B-chromosomal, C-inversion
c) A-two, B-chromosomal, C-alteration d) A-three, B-chromosomal, C-deficiency - β¦Aβ¦ individual show β¦Bβ¦ phenotype but they are the β¦Cβ¦ of the disease as there is 50% probability of
transmission of mutant gene to its progeny
Choose the correct option for A, B and C
a) A-homozygous, B-affected, C-carrier b) A-homozygous, B-unaffected, C-carrier
c) A-heterozygous, B-unaffected, C-carrier d) A-heterozygous, B-affected, C-carrier - If male is TT and female is tt than they contribute pollen and egg respectively with
a) T and T gametes b) tt and TT gametes c) TT and tt gametes d) T and t gametes - Number of linkage group in Pisum sativum is
a) 2 b) 5 c) 7 d) 9 - In Mendelβs experiments with garden pea, round seed shape (RR) was dominant over wrinkled seeds (rr),
yellow cotyledon (YY) was dominant over green cotyledon (yy). What are the expected phenotypes in the
F2- generation of the cross RRYYΓrryy?
a) Only round seeds with green cotyledons b) Only wrinkled seeds with yellow cotyledons
c) Only wrinkled seeds with green cotyledons d) Round seeds with yellow cotyledons and wrinkled
seeds with yellow cotyledons - BB = for black colour alleles
bb = for brown colour alleles
Offspring of a cross between a black mouse and brown mouse allowed to interbreed than find out the
percentage of black coat in them
a) 75%
b) 50%
c) Cross is not possible because black and brown mouse are different species
d) 100%
NEET MCQs: Inheritance & Variation – : ANSWER KEY :
ο»Ώ
1) b 2) a 3) c 4) a
5) c 6) d 7) a 8) b
9) a 10) b 11) d 12) a
13) d 14) c 15) a 16) a
17) c 18) a 19) d 20) c
21) c 22) a 23) a 24) d
25) a 26) b 27) c 28) a
29) c 30) c 31) c 32) c
33) a 34) c 35) c 36) b
37) b 38) d 39) a 40) d
41) d 42) a 43) c 44) a
45) b 46) b 47) b 48) a
49) d 50) c 51) a 52) a
53) a 54) d 55) b 56) c
57) a 58) a 59) a 60) a
61) d 62) b 63) c 64) d
65) c 66) c 67) b 68) d
69) c 70) d 71) c 72) d
73) d 74) c 75) c 76) d
77) a 78) a 79) a 80) c
81) c 82) b 83) b 84) a
85) d 86) a 87) a 88) c
89) c 90) c 91) a 92) d
93) a 94) a 95) d 96) a
97) d 98) c 99) c 100) c
101) c 102) b 103) c 104) c
105) c 106) a 107) a 108) b
109) d 110) a 111) c 112) c
113) a 114) d 115) d 116) a
117) b 118) c 119) a 120) d
121) a 122) a 123) b 124) b
125) c 126) a 127) c 128) b
129) d 130) c 131) a 132) c
133) b 134) d 135) d 136) b
137) c 138) d 139) c 140) d
141) a 142) b 143) a 144) c
145) b 146) b 147) a 148) a
149) c 150) d 151) a 152) a
153) c 154) d 155) a 156) a
157) a 158) c 159) a 160) c
161) c 162) c 163) d 164) c
165) c 166) c 167) c 168) b
169) c 170) c 171) c 172) c
173) b 174) b 175) a 176) a
177) b 178) c 179) d 180) b
181) a 182) b 183) d 184) b
185) b 186) b 187) a 188) a
189) a 190) a 191) c 192) d
193) c 194) c 195) d 196) c
197) d 198) a 199) b 200) a
NEET MCQs: Inheritance & Variation Page| 57 – ANSWER KEY – HINTS AND SOLUTIONS :
1 (b)
Haemophilia is a recessive X-linked disease. A
female with defected single X-chromosome is
normal but, carrier of disease, and male with
defected single X-chromosome is haemophilic.
2 (a)
Genetic disorder may be grouped into two
categories
(i) Mendelian Disorders These genetic disorder
are mainly caused by alternation and mutation in
the single gene. They are transmitted to offsprings
following the principle of inheritance. Mendelian
disorder can be dominant or recessive. π.π.,
haemophilia, colour blindness, sickle-cell
anaemia, cystic fibrosis, phenylketonuria,
thalassaemia.
(ii) Chromosomal Disorders Chromosomal
disorder are caused due to excess, absence, or
abnormal arrangement of one or more
chromosome, π.π., Turnerβs syndrome, Downβs
syndrome, etc
3 (c)
The term gene was coined by Johanssen.
4 (a)
A dihybrid cross involves two pairs of contrasting
characters, e.g., yellow round seeded plant and
wrinkled. Green seedes plant(both pure lines)
homozygous. When a dihybrid cross is made
between two pure line of homolzygous parents,
then the πΉ1 generation shows hybrids with
dominant phenotypic effect. When πΉ1
heterozygous plants are self-ferilized to
produceπΉ2 generation, four types of combinations
are obtained of which two are similar to parental
combination and other two are new
combinations. The phenotypic dihybrid ratio of
these four combinations in πΉ2 generation comes
out to be 9 : 3 : 3 : 1, while the genotypic dihybrid
ratio is 1 : 2 : 2 : 4 : 1 : 2: 1 : 2 : 1.
5 (c)
Chromosome is made up of DNA and histone
proteins.
6 (d)
Baldness is not a sex-limited trait. Balaness is a
sex influenced trait.
Linkage is an exception to the principle of
independent assortment in heredity.
Galactosemia is a hereditary disease that is
caused by the lack of a liver enzyme required to
digest galactose.
Small population size results in random genetic
drift in population.
7 (a)
The πΉ1 offsprings of pure tall and pure dwarf are
heterozygoous tall, which on selfing produces 1 :
1 ratio of breeding tall to breeding dwarf.
8 (b)
Exposure of βXβ rays enhance the frequency of
crossing over
9 (a)
The genotype of trihybrid would be AaBbCc. Eight
different types of gametes ABC, ABc, AbC, Abc,
aBC, aBc, abC, abc would be formed. The number
of zygotes would be 82=64.
10 (b)
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The genetic composition of an organism, i.e., the
combination of all alleles possessed by an
organism is called genotype
11 (d)
In polyploidy there are more than one set of
chromosomes is presenβt in an organisms. It only
happens when cytokinesis doesnβt take place in
proper way
12 (a)
12
A dihybrid cross in pea
plant between yellow round (smooth) seeded and green wrinkled seeded plant. The cross proves the
principle of independent assortment
13 (d)
When the F1-hybrid (Rr Yy) of a dihybrid cross is
test crossed (crossed with double recessive
parent rryy), the F2-offspring appear in the
phenotypic and genotypic ratio of 1 : 1 : 1 : 1
confirming that F1-offspring was heterozygous in
both the traits. It is a cross between RrYyΓrryy.
14 (c)
Allelomorphs or simply called allele represents a
pair of contrasting characters
15 (a)
Harmful mutation does not get elimated from the
gene pool because most of the harmful mutations
are recessive and they carried by heterozygous
condition in the individual. If they (mutation) are
dominant then they easily get eliminated by the
death of an organism
16 (a)
A-Common, B-Rare
17 (c)
Mendel died in 1884 long before his work came to
recognized. It was in 1900 when three worker
independently rediscovered the principles of
heredity already worked out by Mendel.
They were Hugo de Vries of Holland, Carl Correns
of Germany and Eric Tiron and Tschermark of
Austria
18 (a)
In gynandromorphs, some cells of body contain
XX and some cells XY genotype.
19 (d)
Post Mendelian Discoveries
Gene interaction is the influence of alleles and
nonalleles ion the normal phenotypic expression
of genes. It is two types, intragenic (allelic) and
intergenic (nonallelic). In the intragenic
interaction the two allels (present on the same
gene locus on the two homologous chromosome)
of a gene interact in such a way as to produce a
phenotypic expression different from typical
dominant-recessive phenotype, π.π., incomplete
dominance, codominance, multiple alleles.
In intergenic or non-allelic interaction, two or
more independent gene present on the same or
different chromosomes interact to produce
different expression, π.π., epistasis, duplicate
genes, complementary genes, supplementary
genes, lethal genes, inhibitory genes, etc.
20 (c)
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Intermediate inheritance is incomplete
dominance in which dominant factor of a
heterozygote does not completely mask the
expression of recessive allele. In incomplete
dominance, genotypic and phenotypic ratio
remain the same and is 1 : 2 : 1.
21 (c)
Green pod colour is dominant.
7 dominant traits, 7 recessive traits total 14 traits
or 7 oppossing pairs of traits
Characters Dominant
Traits
Recessive
Traits
Seed shape
Seed colour
Flower
colour
Pod shape
Pod colour
Flower
position
Stem
height
Round
Yellow
Violet
Full
Green
Axial
Tail
Wrinkled
Green
White
Constricted
Yellow
Terminal
Dwarf
22 (a)
IA IB are the dominant form of I gene, I is
recessive form
23 (a)
A-statistical analysis; B-mathematical logic
24 (d)
ZW and ZZ and ZOZZ.
ZW and ZZ Type of Sex Determination This
mechanism operates in certain insects (butterflies
and moths) and in vertebrates (fishes, reptiles
and birds). The male has two homomorphic sex
chromosomes (ZZ) and is homogametic and the
female has two heteromorphic sex chromosomes
(ZW) and is heterogametic. There are thus two
types of eggs with Z and with W and only one type
of sperms. i.e., each with Z
WZ-ZZ types of sex determination
25 (a)
If a character is expressed equally in the
homozygous and heterozygous conditions, it is
called dominant and the other character is said to
be recessive. In given question, βTallβ character is
dominant over βdwarfβ, hence, the cross shows
dominance and segregation of traits.
26 (b)
The best method to determine homozygosity and heterozygosity of an individual is back cross.
Crossing of F1 (dominant phenotype) to any one of the parent called back cross and when phenotype of
crossing parent is recessive than this is called test cross. The progeny of such cross can easily be analysed
to predict the genotype of test organism
27 (c)
Presence of one Barr body indicates the person
under investigation is a normal female.
28 (a)
A-Male, B-Female, C-Gametes.
XY and XY type sex determination seen in many
insect and mammals including humans. Males
have X and Y chromosome along with autosome
and females have pair of βXβ chromosome along
with autosome
Parents Phenotypes Male
Female
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Genotypes 44A + XY
44A + XX
Gametes 22A + X 22A+Y
22A + A22A + X
22A+ X 22A+X
Children 22A + X 44A + XX 44 A + XY
Female
22A + Y 44 A + XY 44 A + XY
Male
Sex ratio Female : Male = 1 : 1
In plants The flowering plants are mostly bisexual
and lack sex chromosomes. The unisexual
flowering plants tent to have XX-XY type of sex
chromosomal mechanism for sex determination.
The female plants are XX and male plants are XY.
XX and XO Type of Sex Determination
Found in insect like grasshopper, cockroaches and
bugs. Males have only X sex-chromosome and
autosomes, female have pair of X-chromosome
and autosome
Parents Phenotypes Male Female
Genotypes π΄π΄+ππ π΄π΄+ππ
Gametes π΄+π,π΄+π π΄+π,π΄+π
οΏ½
οΏ½π-generation
XX-XO type of sex determination
29 (c)
Female is sterile.
Disorders Autosomal/Sex
Linked
Symptoms Effects
Downβs
syndrome
Autosomal
aneuploidy
(trisomy, +21)
Mongolian eyefold
(epicanthus), open
mouth, protruded
tongue, projected
lower lip, many
loops on finger tip,
palm crease
Retarded
mental
development
IQ (below 40)
Turnerβs
syndrome
Sex
chromosomal
monosomy 44
- XO
Short stature
females (<5β),
webbed neck, body
hair absent
menstrual cycle
absent. Sparse
pubic hair,
underdeveloped
breasts narrow lips
puffy fingers
Sterile
hearing
problem
Klinefelterβs
syndrome
Sex
chromosomal
aneuploidy
(tri/tetrasomy
of X
chromosome)
44+XXY
44+XXXY
The males are tall
with long legs,
testes small, sparse
body hair, Barr
body present,
breast enlargement
Gynaecomast
ia azospermia
sterile
Some Examples of Aneuploidy
(i) Downβs syndrome-21 trisomy
Symptoms
(a) Short statured with small round head
(b) Partially open mouth with protruding furrowed tongue
(c) Palm is broad with characteristic palm crease
(d) Slow mental development
(ii) Turnerβs syndrome
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Cause Absence of one of the X-chromosomes, resulting in the karyotype 44+XO
Symptoms
(a) Sterile female with rudimentary ovaries
(b) Shield-shaped thorax
(c) Webbed neck
(d) Poor development of breasts
(e) Short stature, small uterus, puffy fingers
(iii) Klinefelterβs syndrome
Cause Presence of an additional copy of X-chromosome resulting in the karyotype 44+XXY
Symptoms
(a) Sex of the individual is masculine but possess feminine characters
(b) Gynaecomastia, i.e., development of breasts
(c) Poor beard growth and often sterile
(d) Feminine pitched voice
30 (c)
The environmental stress (as pesticides) does not
cause the direct changes in genome, instead, it
simply selects rather persisting mutations, which
result in phenotypes that are better adapted to
the new environment (e.g., certain pesticides).
31 (c)
A Lampbrush chromosomes is made up of two
homologous chromosomes held at several places
by chiasmata. The chromosomes are found in
oocytes of many invertebrates and all vertebrates
except some mammals. Lampbrush chromosomes
are found during the extended diplotene phase of
first meiotic division.
32 (c)
A gene consists of a polynucleotide sequence that
encodes a functional polypeptide or RNA
sequence.
33 (a)
XY and XY type sex determination seen in many
insect and mammals including humans. Males
have X and Y chromosome along with autosome
and females have pair of βXβ chromosome along
with autosome
Parents Phenotypes Male
Female
Genotypes 44A + XY
44A + XX
Gametes 22A + X 22A+Y
22A + A22A + X
22A+ X 22A+X
Children 22A + X 44A + XX 44 A + XY
Female
22A + Y 44 A + XY 44 A + XY
Male
Sex ratio Female : Male = 1 : 1
In plants The flowering plants are mostly bisexual
and lack sex chromosomes. The unisexual
flowering plants tent to have XX-XY type of sex
chromosomal mechanism for sex determination.
The female plants are XX and male plants are XY.
XX and XO Type of Sex Determination
Found in insect like grasshopper, cockroaches and
bugs. Males have only X sex-chromosome and
autosomes, female have pair of X-chromosome
and autosome
Parents Phenotypes Male Female
Genotypes π΄π΄+ππ π΄π΄+ππ
Gametes π΄+π,π΄+π π΄+π,π΄+π
οΏ½
οΏ½π-generation
XX-XO type of sex determination
34 (c)
Frameshift mutations are the mutations caused by
insertion (i.e., addition) or deletion of one or
more nitrogen bases in the DNA or RNA. This type
of mutation alters the nucleotide sequences in all
the genes and hence, the genetic code is changed
totally, fro the point of mutation which results in
the change in biochemical behaviour of the genes.
Base pair substitution mutations involve
substitution of a aitrogen base by another base or
by some derivative of nitrogen base.
35 (c)
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According to law of segregation, the heredity
character in the form of alleles segregate from
each other during gamete formation, i.e, each
gamete carry only one allele of each gene. This is
also called law of purity of gametes. When tall and
dwarf plants are crossed only tall plants are
produced in πΉ1 generation. By selfing of these πΉ1
plants tall and dwarf plants produced in 3 : 1
ratio.
36 (b)
Mendelβs law are able to predict accurately the
pattern of inheritance for a situation in which
alleles shows the complete dominance. Effect of
environment, other alleles did not explained by
the Mendel. Mendel did not know about the
polygenic traits also
37 (b)
Blood group-O has no antigens but A and B
antibodies.
38 (d)
Colour blindness disease was detected by Wilson
in 1910.
39 (a)
In the dihybrid cross between RRYY and rryy
parents, the number of RrYy genotypes in πΉ2
generation will be four.
40 (d)
Allelism refers to presence of alternative forms of
a gene at a given locus. Alleles or allelomorphs are
the two contrasting aspects of the same character
present at a locus of homologous pair of
chromosomes. Now βa-days, the same aspect in
duplicate (TT or tt) of a character is also
considered an allele.
41 (d)
The women with albinic father has gene for
albinism. When this women marries with albinic
men, they produce normal and albinic in 1 : 1
ratio.
42 (a)
ZO and ZZ type of sex determination. This
mechanism occurs in certain buttterfiles and
moths. The female is heterogametic and produces
two types of eggs half with Z and half without Z
chromosome. The males have homomorphic sex
chromosomes and is homogametic. It forms only
one kind of sperms, each with Z-chromosome
Parents Phenotypes Male Female
Genotypes AA + ZZ AA +ZO
Gametes A+Z, A+Z A +Z, A+O
οΏ½
οΏ½π-generation
ZO-ZZ type of sex determination
43 (c)
Mendelβs law of independent assortment states
that,βthe alleles of different genes segregate
independently of each other during meiosisβ.
44 (a)
XX and XO chromosome.
XY and XY type sex determination seen in many
insect and mammals including humans. Males
have X and Y chromosome along with autosome
and females have pair of βXβ chromosome along
with autosome
Parents Phenotypes Male
Female
Genotypes 44A + XY
44A + XX
Gametes 22A + X 22A+Y
22A + A22A + X
22A+ X 22A+X
Children 22A + X 44A + XX 44 A + XY
Female
22A + Y 44 A + XY 44 A + XY
Male
Sex ratio Female : Male = 1 : 1
In plants The flowering plants are mostly bisexual
and lack sex chromosomes. The unisexual
flowering plants tent to have XX-XY type of sex
chromosomal mechanism for sex determination.
The female plants are XX and male plants are XY.
XX and XO Type of Sex Determination
Found in insect like grasshopper, cockroaches and
bugs. Males have only X sex-chromosome and
autosomes, female have pair of X-chromosome
and autosome
Parents Phenotypes Male Female
Genotypes π΄π΄+ππ π΄π΄+ππ
Gametes π΄+π,π΄+π π΄+π,π΄+π
οΏ½
οΏ½π-generation
Page| 65
XX-XO type of sex determination
45 (b)
A-Chromatid, B-Allele pair, C-Genetic composition
46 (b)
The position of centromere determines the shape
of chromosome.
47 (b)
After schooling Mendel joined Augustinian
monastery of St. Thomas at Brunn (then in
Austria now Brunn in Czechoslovakia) in 1843 at
the age of 21. At the age of 25 (1847), he was
made a prist in that monastery
48 (a)
It was TH Morgan who clearly proved and define
linkage on the basis of the breeding experiments
in fruitfly. In 1911, Morgan and Castle proposed
βchromosomalβ theory of linkageβ
49 (d)
Francis Galton(1885) gave the term eugenics.
Eugenics is the improvement of human race by
the application of principles of genetics. The other
meaning of eugenics is βscience of being well
bornβ.
50 (c)
The test cross involves the crossing of F1hybrid
with a double recessive genotypic parent. By test
cross, the heterozygocity and homozygocity of the
organism can be tested.
51 (a)
Tetraploid endosperm is obtained, when a diploid
female and tetraploid male plants are crossed.
52 (a)
Colour Blindness
(i) It is a sex-linked recessive disorder
(ii) It results in defect in either red or and green
cone cells of eye resulting in failure to
discriminate between red and green colour
(iii) The gene for colour blindness is present on X
chromosome
(iv) It is observed more in males (XcY) because of
presence of only one X-chromosome as compared
to two chromosomes in famales
53 (a)
When the πΉ1-hybrid is crossed with recessive
parent, both phenotypes appear in progeny and
this is called test cross. It gives 1 : 1 ratio in
monohybrid cross and 1 : 1 : 1 : 1 ratio in dihybrid
cross.
54 (d)
Thus, the genotype of parents will be BOΓAO.
55 (b)
Symbol in pedigree chart represents still death
56 (c)
Histones are basic proteins found in the
eukaryotic chromosomes. These are rich in basic
amino acids lysine and arginine. There are
basically five types of histones, i.e.,
H1,H2A,H2B,H3 and H4 which have been studied
in almost all eukaryotic cells.
57 (a)
In monosomic condition, one chromosome is
missing from the somatic chromosome
complement. It is denoted by 2n-1. When somatic
cells of an organism contain three copies of one
chromosome, the condition is known as trisomy.
It is denoted by 2n+1. Therefore, monosomic
trisomy is represented as 2n-1+1.
58 (a)
Baldness is common in humans. Hereditary
baldness is carried by a dominant autosomal
gene. It develops only in men and never in
women.
59 (a)
Thalassaemia
(i) It is an autosome-linked recessive disesase
(ii) It occurs due to either mutation or deletion
resulting in reduced rate of synthesis of one of
globin chains of haemoglobin
(iii) Anaemia is the characteristic of this disease
(iv) Thalassaemia is classified into two types
- π-thalassaemia Production of Ξ±-globin
chain is affected. It is controlled by the
closely linked genes HBA1 and HBA2 on
Page| 66
chromosome 16. It occurs due to mutation
or deletion of one or more of the four
genes.
- π-thalassaemia Production of Ξ²-globin
chain is affected. It occurs due to mutation
of one or both HBB genes on chromosome
11
60 (a)
The term βmutationβ was introduced by Hugo de
Vries in 1901 and his mutation theory of
evolution called mutation theory of evolution.
Mutation is new sudden inheritable change in
organism due to permanent change in their
genotype
61 (d)
Because in sex linked inheritance the chance of
girl or female to be affected is almost nill.
Generally, the females are carriers and in
heterozygous condition
62 (b)
Non-disjunction is the condition in which the
separation of chromosome doesnβt take place
during cell division. In 44+XY non-disjunction
there is non-separation of XY gene is there, which
leads to the formation of sperm having genotypes,
22+XY and 22
63 (c)
Linkage prevents independent assortment.
64 (d)
Sex influenced trait.
Finalization of sex at the time of fertilization is
known as sex determination. All sex linked
character show criss-cross inheritance and firstly
it was studied and discovered by TH Morgan
(1910). Sex related trait may be divided into three
types
(i) Sex Linked Traits They are those traits the
determining genes of which are found on the sex
chromosomes. All the sex-linked traits present on
a sex chromosome are inherited together
(ii) Sex Limited Traits They are autosomal traits
which are expressed in a particular sex in
response to sex hormones although their genes
also occur in the other sex, e.g., milk secretion in
mammalian females, pattern baldness in males.
The gene for baldness behaves as an autosomal
dominant in males and autosomal recessive in
females
(iii) Sex Influenced Traits The traits are not due to
particular genes but are by products of sex
hormones, e.g., low pitched voice, beard
moustaches. In males, pattern baldness is related
to both autosomal genes as well as excessive
secretion of testosterone
65 (c)
Since in an individual only two alleles can be
present, multiple alleles can be found only when
population studies are made
66 (c)
Biological concept of species says that only the
members of a species can breed freely in nature to
produce fertile offsprings. The plant tobacco
(πππππ‘ππππ) has two different species,
οΏ½
οΏ½ππππ‘ππππ π‘ππππππ’π and πππππ‘ππππ π π¦ππ£ππ π‘πππ .
These two species cannot reproduce freely.
67 (b)
In duplication there is increase in size of genes by
duplication of it segment of a chromosome.
Mainly seen in case of plants. But in deletion there
is loss of genes or segment of chromosome
68 (d)
The types of gametes produced by a plant depend
upon the number of hetrozygous pair.
Number of types of gametes=2π
N=Number of heterozygous pair
21=2
The gametes are-ABC and AbC.
69 (c)
In trisomic condition, diploid organism have extra
chromosome represented by the chromosomal
formula2π+1 . One of the pairs of chromosomes
has an extra member, so that a trivalent may be
formed during meiotic prophase, e.g., Downβs
syndrome (45+XX or 45+XY), Klinefelterβs
syndrome (44 + XXY).
In monosomic, diploid organism has one
chromosome of a single pair missing with
genomic formula 2πβ1. Monosomics can from
two kind of gametes, (n) and (n-1),
e.g., Turnerβs syndrome (44 + X).
70 (d)
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When a normal man marries a normal woman,
whose father was colourblind then their 50%
sons are colourblind (50% sons normal) and all
the daughters are phenotypically normal(carrier
woman also are phenotypically normal).
The female parent is carrier as it receives a
defective X-chromosome from her father.
71 (c)
Testosterone in male secreted by Leydig cells. In
the male testosterone is essential for
development of secondary sexual character and
related to baldness also
72 (d)
The disorder cystic fibrosis, sickle cell anaemia,
colour blindness and haemophilia are caused due
to the abnormality in gene (Mendelian factor).
Turnerβs syndrome is due to chromosomal
abnormality. It is characterized by 44 autosomes
and only one X-chromosome.
73 (d)
Haemophilia is a X-linked disorder not Y-linked.
74 (c)
(Homozygous tall) Γ (Homozygous dwarf)
Phenotypic ratio 1 : 1 (50% tall, 50% dwarf)
Genotypic ratio 1 : 1
75 (c)
Ξ³βrays generally induce mutations.
76 (d)
Since genotypes/phenotypes of both parents are
same but only sources of gametes are reversed,
these crosses are called reciprocal crosses.
77 (a)
Man has only one X-chromosome that is inherited
to his daughter. Therefore, a hereditary disease,
which is X-chromosomal linked, is never passed
on from father to son.
78 (a)
Bateson gave the coupling and repulsion
hypothesis for linkage and crossing over.
Similar genes remain together they donβt go for
crossing over. Bateson called them coupling
gones.
While on the other hand dissimilar gene segregate
crossing over takes place. Bateson called them
repulsion parents gene
79 (a)
The blood group type in human provides an
example of multiple allelism (i.e., presence of
more than two allele for one gene). There are
three A, B and O blood groups allele usually given
the symbolIA,IB and Ii.IA and IB are codominant
to each other but both are dominant to Ii. The
offspring of parents having IA and I1 allele with be
IAIi having blood group-A.
A-IAIi
B-IBIi
AB-IAIB
O-IiIi
80 (c)
A person having 45 chromosomes instead of 46
due to lack of Y-chromosome is suffering from
Turnerβs syndrome.
81 (c)
Opposite phenomena.
Strength of linkage between two genes inversely
proposed to the distance of two gene means if two
genes are closely placed then they have high
percentage of linkage and if they placed for then
there is low percentage of linkage.
Linkage and recombination are two opposite
phenomena. In linkage two genes remains united
and in recombination the two get apart due to
crossing over during gametogenesis (meiosis)
82 (b)
Johanssen (1909) proposed the term gene. Genes
are made up of DNA, i.e., a DNA segment
associated with proteins, which can be copied in
the form of RNA and is responsible for hereditary
characters. Genes have full control over protein
synthesis.
83 (b)
2n (diploid).
Haploid diploid mechanism of sex determination
(haplodiploidy).
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Hymenopterous insect such as bees, wasps ants
show unique phenomena in which an unfertilized
egg develops into male and female develops from
fertilized egg.
In honeybee, the quality of food determines
whether a diploid larva will become a fertile
queen or a sterile worker female. A larva fed on
royal jelly a secretion from the mouth of mussing
workers grows into a queen, whereas a larva fed
on pollen and nectar grows into a worker bee
84 (a)
For the given case, the imprints need to be used
only on plates with streptomycin.
85 (d)
Phenylketonuria (PKU) is homozygous recessive
autosomal disorder associated with metabolism
and the gene for it is present on chromosome-12.
Huntingtonβs disease (Huntingtonβs chorea) is a
dominant autosomal disorder due to an allele on
short arm of chromosome-4. Sickle cell anaemia is
due to codominant autosomal allele HbS present
on chromosome-11.
86 (a)
The genes are arranged in a linear fashion on the
chromosome.
87 (a)
According to πππ βπ‘ππππ effect of Lewis, when
two genetic loci produce identical phenotypes in
οΏ½
οΏ½ππ and π‘ππππ position, they are considered to be
pseudoalleles and phenomenon as pseudoallelism.
88 (c)
Factor-II β Prothrombin
Factor βIII β Thromboplastin
Factor βVIII β Antihaemophilic globulin
Factor βXII β Hageman factor
89 (c)
The longest chromosome is seen in Trillium
(30π).
90 (c)
F1.
Mendel cross-pollinated a pure tall pea plant
(100-120 cm hight) and a pure dwarf pea plant.
(only 22 to 44 cm hight). He called them parental
generation, expressed now-a-days by symbol P.
This hybridization popularly called as
monohybrid cross
This three generations of pea plants after crossing
a pure tall plant with a dwarf one. The plants of
F1-generation are all tall, of F2-generation three
tall and one dwarf. One third of the tall plants are
pure, while the remaining behave as hybrids
οΏ½
οΏ½π-generation Seeds collected from the parental
generation called first filial generation or F1
generation
οΏ½
οΏ½π-generation F1-plants pollinated among them
self (self breeding or inbreeding) and seed
produced by F1-plants called F2-generation. They
were in ratio 3:1 (three tall and one dwarf).
οΏ½
οΏ½π-generation Mendel allowed F2-plant to form
seed by self-pollination called F3-generation.
Mendel observed that tall and dwarf plant behave
differently
(i) Dwarf plant produced dwarf plant on self
pollinated
(ii) In tall plants one third plants breed true so
they were pure
(iii) Other two third plant behave like parents and
give tall to dwarf plants 3 : 1 indicate that their
parents have dwarf genes also
91 (a)
A-Linked; B-Unlinked gene
92 (d)
Allelic sequence variation has traditionally been
described as a DNA polymorphism if more than
one variant (allele) at a locus occurs in human
Page| 69
population with a frequency greater than 0.01. In
simple terms, if an inheritable mutation is
observed in a population at high frequency, it is
referred to as DNA polymorphism.
93 (a)
A-Extremely, B-Carrier, C-Haemophilia
94 (a)
The Rh factor causes erythroblastosis foetalis,
when a woman who is Rhβ marries a man, who is
Rh+ , their first child will be safe (which is Rh+)
but during pregnancy some blood of foetus and
mother mixes due to which the mother develops
antibodies against her foetus antigen which is
Rh+.
95 (d)
Landsteiner divided human population into four
groups based on the presence of antigens found in
their RBCs. Each group represented a blood
group. Thus, there are four types of blood groups
A, B, AB and O. Blood group-O does not contain
any antigen on RBCs, hence can be given to any
person, thatβs why, this blood group is called
universal donor.
96 (a)
Alleles or allelomorphs are alternative forms of
the same gene, e.g., for height of plant βTβ and βtβ.
Homologous chromosomes are a pair of
chromosomes having similar genes, which control
the same characters.
97 (d)
Telomeres are ends of chromosome, that have
repetitive DNA sequences and are stable and
resistant to exonuclease digestion hence, essential
for chromosome stability.
98 (c)
Intermediate inheritance also called the
incomplete dominance. In that inheritance the
phenotypic and genotypic ratio are same. The
classical examples are = four Oβ clock plant and
snapdragon.
Mirabilis jalapa shows incomplete dominance
The ratio of pink and white flower will be 1 : 1
99 (c)
Mendelian disorder may be dominant or recessive
100 (c)
In African population, sickle cell anaemia provides
immunity against malaria.
101 (c)
Aneuploidy is the variations in individual
chromosomal number. Actually, loss or gain of
individual chromosomes upsets the balance and,
hence normal development is not possible.
103 (c)
Black feathered hen = BB
White feathered cock = bb
Blue feathered fowl = Bb
104 (c)
Histones are special type of basic protein
associated with DNA and form chromosome. RNA,
protein, carbohydrate, fat, doesnβt find in
chromosomes
105 (c)
In pedigree
Square represents male blackened square or
circle represents affected individual.
Horizontal line represents-parents
The study of inheritance of genetic traits in
several generations of a human family in the form
of a family tree diagram is called pedigree
analysis.
Advantages
(i) It helps in genetic counselling to avoid
disorders
Page| 70
(ii) It shows the origin of a trait and flow of a trait
in a family
(iii) It is important to know the possibility of a
recessive allele that can cause genetic disorders
like colour blindness, haemophilia, etc.
Signosed in the pedigree are
106 (a)
In the given pedigree chart only males are
affected. So, it can be easily inferred that the given
trait is connected to Y-chromosome. The genes,
which are present on the Y-chromosome are
called holoandric genes
107 (a)
In the gametogenesis meiosis occur. The diploid
chromosome become haploid, so the probability
of side is sperm lacking one recessive autosomal
allele and holandric gene is half
108 (b)
F3-generation obtained by selfing of F2
generation.
Mendel cross-pollinated a pure tall pea plant
(100-120 cm hight) and a pure dwarf pea plant.
(only 22 to 44 cm hight). He called them parental
generation, expressed now-a-days by symbol P.
This hybridization popularly called as
monohybrid cross
This three generations of pea plants after crossing
a pure tall plant with a dwarf one. The plants of
F1-generation are all tall, of F2-generation three
tall and one dwarf. One third of the tall plants are
pure, while the remaining behave as hybrids
οΏ½
οΏ½π-generation Seeds collected from the parental
generation called first filial generation or F1
generation
οΏ½
οΏ½π-generation F1-plants pollinated among them
self (self breeding or inbreeding) and seed
produced by F1-plants called F2-generation. They
were in ratio 3:1 (three tall and one dwarf).
οΏ½
οΏ½π-generation Mendel allowed F2-plant to form
seed by self-pollination called F3-generation.
Mendel observed that tall and dwarf plant behave
differently
(i) Dwarf plant produced dwarf plant on self
pollinated
(ii) In tall plants one third plants breed true so
they were pure
(iii) Other two third plant behave like parents and
give tall to dwarf plants 3 : 1 indicate that their
parents have dwarf genes also
109 (d)
W Bateson and R C Punnett observed
complementary gene interaction for flower colour
in sweet pea (πΏππ‘βπ¦ππ’π ππππππ‘π’π ). In
complementary interaction, two separate pairs of
genes interact to produce the phenotype in such a
way that neither of the dominant genes is
expressive unless the other one is present. In πΉ2
generation, complementary genes produce a ratio
of 9 : 7.
110 (a)
Occasionally a single gene product may produce
more than one effect. For example starch
synthesis in pea seeds is controlled by one gene. It
has two allele (B and b). Starch is synthesized
effectively by BB and have bigger grains. In
contrast bb homozygous have lesser efficiency in
starch synthesis and produce smaller grains
111 (c)
In π·πππ ππβπππ, sex is determined by the ratio
number of X-chromosomes to the set of
autosomes.
112 (c)
The genotypic and phenotypic ratio of 1 : 2 : 1
with red, pink and white flowers are produced in
οΏ½
οΏ½ππππππππ ππππππ, when red flowered plants (RR)
Page| 71
are crossed with white flowered (rr). It occurs
due to allelic gene interactions, called, incomplete
dominance. In which, both of the allelomorphic
genes will have partial or incomplete dominance
and F1-hybrid will show mixture of characters of
two parents.
113 (a)
Meiosis is an important stage in sexual
reproduction. During meiosis, genetic
recombination occurs as a result of crossing over.
114 (d)
Blood group of children may be A, B, AB and O.
115 (d)
The genes, which are present very far from each
other tend to get unlinked and they arethe most
chances for crossing over
116 (a)
Given diagram depicits the sex linked inheritance
in given options haemophilia is the sex-linked
character
117 (b)
Incomplete dominance or blending inheritance is
the phenomenon, in which the two genes of
allelomorphic pair are not related as dominant or
recessive but each of them expresses itself
partially, thus the πΉ1 hybrids exhibit a mixture or
blending of characters of both the parents. In πΉ2
generation, the phenotypic ratio obtained is 1 : 2 :
- 118 (c)
Haemophilia is a disease, which is caused due to
lack of blood clotting factor. It appears only in
human male which can be transferred to their
grandson through his carrier daughter.
119 (a)
In the given option only codominance does not
obey Mendelβs laws.
The phenomenon of expression of both the alleles
in heterozygote is called codominance. As the
result the phenotype is different from both
homozygous genotype.
Examples - Blood group is the good example
codominance - ABO blood groups are controlled by gene
I. The gene (l) has three allele
IA,IB,i,IA,IB produce slilghtly different
form of sugar while i does not produce
any kind of sugar. - IA,IB are dominant alleles where as i is
recessive alleles - Since, there are three different allele,
there are six different combination of
these three alleles are possible and four
phenotypes (A, B, AB and O)
Genetic Basis of Blood Groups in Human
Population
Allele
from
Parent
1
Allele
from
Parent
2
Genotype
of
Offspring
Blood
Types of
Offspring
IA IA IAIA A
IA IB IAIB AB
IA i IAi A
IB IA IAIB AB
IB IB IBIB B
IB i IBi B
i i ii O
When IA and IB are present together they both
express their own types of sugars this is because
of co-dominance. ABO blood grouping also
provides a good example of multiple alleles.
Here, you can see that there are more than two,
i.e., three alleles governing the same character.
Since, in an individual only two alleles can be
present multiple alleles can be found only when
population studies care made. Dominance is not
an autonomous features of a gene. It depends on
much on the gene product
120 (d)
11th.
Thalassaemia
(i) It is an autosome-linked recessive disesase
(ii) It occurs due to either mutation or deletion
resulting in reduced rate of synthesis of one of
globin chains of haemoglobin
(iii) Anaemia is the characteristic of this disease
(iv) Thalassaemia is classified into two types - π-thalassaemia Production of Ξ±-globin
chain is affected. It is controlled by the
closely linked genes HBA1 and HBA2 on
chromosome 16. It occurs due to mutation
or deletion of one or more of the four
genes. - π-thalassaemia Production of Ξ²-globin
chain is affected. It occurs due to mutation
Page| 72
of one or both HBB genes on chromosome
11
122 (a)
TH Morgan.
Father of experimental genetics is TH Morgan. He
is also called the fly man of genetics because of
selecting fruit fly (Drosophila melanogaster) as
research material in experimental genetics
123 (b)
Mendel gave the laws of inheritance, which
provides the mechanism that explains the pattern
of inheritance
124 (b)
The genotypic ratio can be find out of a dominant phenotype by test cross or by simply Punnett square.
Phenotypic ratio Tall : Dwarf
Genotypic ratio TT : Tt : tt
1 : 2 : 1
A Punnett square used to understand to typical monhybrid cross conducted by Mendal between true
breeding tall plants and true-breeding dwarf plants
Crossing of F1 (dominant phenotype) to any one of the parent called back cross and when phenotype of
crossing parent is recessive than this is called test cross. The progeny of such cross can easily be analysed
to predict the genotype of test organism
125 (c)
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Genes for baldness are located on autosomes and
influenced by androgens, thus, this is more
common in men than in women.
126 (a)
The number of characters studied by Mendel was
seven which were present on four chromosomes.
Three contrasting characters with respect to pea
pod are (i) pod shape,(ii) pod colour, (iii)pod
position.
127 (c)
Chlorinated hydrocarbons are mutagen pollutants
which can cause mutation in gene.
128 (b)
Both genes and chromosomes (Mendelian
factors) whether dominant or recessive are
transmitted from generation to generation in the
pure or unaltered form. It is also called law of
purity of gametes
129 (d)
The study of inheritance of genetic traits in
several generations of a human family in the form
of a family tree diagram is called pedigree
analysis.
Advantages
(i) It helps in genetic counselling to avoid
disorders
(ii) It shows the origin of a trait and flow of a trait
in a family
(iii) It is important to know the possibility of a
recessive allele that can cause genetic disorders
like colour blindness, haemophilia, etc.
Signosed in the pedigree are
130 (c)
Some genes control phenotypic traits and at the
same time they also influence the viability of the
individuals. The influence of these genes on
viability is such that it may cause death of
individual carrying them. Such genes are called
lethal genes.
131 (a)
Absence of one X-chromosome (44 with XO).
Disorders Autosomal/Sex
Linked
Symptoms Effects
Downβs
syndrome
Autosomal
aneuploidy
(trisomy, +21)
Mongolian eyefold
(epicanthus), open
mouth, protruded
tongue, projected
lower lip, many
loops on finger tip,
palm crease
Retarded
mental
development
IQ (below 40)
Turnerβs
syndrome
Sex
chromosomal
monosomy 44
- XO
Short stature
females (<5β),
webbed neck, body
hair absent
menstrual cycle
absent. Sparse
pubic hair,
underdeveloped
breasts narrow lips
puffy fingers
Sterile
hearing
problem
Page| 74
Klinefelterβs
syndrome
Sex
chromosomal
aneuploidy
(tri/tetrasomy
of X
chromosome)
44+XXY
44+XXXY
The males are tall
with long legs,
testes small, sparse
body hair, Barr
body present,
breast enlargement
Gynaecomast
ia azospermia
sterile
Some Examples of Aneuploidy
(i) Downβs syndrome-21 trisomy
Symptoms
(a) Short statured with small round head
(b) Partially open mouth with protruding furrowed tongue
(c) Palm is broad with characteristic palm crease
(d) Slow mental development
(ii) Turnerβs syndrome
Cause Absence of one of the X-chromosomes, resulting in the karyotype 44+XO
Symptoms
(a) Sterile female with rudimentary ovaries
(b) Shield-shaped thorax
(c) Webbed neck
(d) Poor development of breasts
(e) Short stature, small uterus, puffy fingers
(iii) Klinefelterβs syndrome
Cause Presence of an additional copy of X-chromosome resulting in the karyotype 44+XXY
Symptoms
(a) Sex of the individual is masculine but possess feminine characters
(b) Gynaecomastia, i.e., development of breasts
(c) Poor beard growth and often sterile
(d) Feminine pitched voice
132 (c)
The recessive genes located on X-chromosome in
humans are always expressed in males because a
female may be homozygous or heterozygous,
while male is always hemizygous (i.e., only one
allele is present).
133 (b)
Strength of linkage between two genes inversely
proposed to the distance of two gene means if two
genes are closely placed then they have high
percentage of linkage and if they placed for then
there is low percentage of linkage.
Linkage and recombination are two opposite
phenomena. In linkage two genes remains united
and in recombination the two get apart due to
crossing over during gametogenesis (meiosis)
134 (d)
Fruitfly is excellent model for genetics because
(i) Life cycle is very short (14 days)
(ii) Can be feed on simple synthesis medium
(iii) Single mating produces large number of
progeny
(iv) Clear differentiation of sexes
(v) Variation can be seen simply by hand lens or
simple microscope
(vi) They (fruitfly) are easy to handle
136 (b)
If both parents have blood group-AB then the
possible blood groups of children are A, B and AB.
137 (c)
Test cross is a cross in which the dominant F1-plant crosses with the homozygous recessive parents plant.
Page| 75
Crossing of F1 (dominant phenotype) to any one of the parent called back cross and when phenotype of
crossing parent is recessive than this is called test cross. The progeny of such cross can easily be analysed
to predict the genotype of test organism
138 (d)
The ability of a gene to have multiple effects is
known as pleiotropy and this phenomenon
pleiotropism. The basis of pleiotropy is the
interrelationship between the metabolic
pathways that may contribute towards different
phenotypes.
139 (c)
When two pea plants having red (dominant)
coloured flowers with unknown genotype are
crossed, the 75% red and 25% white flowered
plants will be produced by following the law of
Mendel. This is possible only if the parents are
heterozygous.
141 (a)
1
4
th and 3
4
th.
Mendel cross-pollinated a pure tall pea plant
(100-120 cm hight) and a pure dwarf pea plant.
(only 22 to 44 cm hight). He called them parental
generation, expressed now-a-days by symbol P.
This hybridization popularly called as
monohybrid cross
This three generations of pea plants after crossing
a pure tall plant with a dwarf one. The plants of
F1-generation are all tall, of F2-generation three
tall and one dwarf. One third of the tall plants are
pure, while the remaining behave as hybrids
οΏ½
οΏ½π-generation Seeds collected from the parental
generation called first filial generation or F1
generation
οΏ½
οΏ½π-generation F1-plants pollinated among them
self (self breeding or inbreeding) and seed
produced by F1-plants called F2-generation. They
were in ratio 3:1 (three tall and one dwarf).
οΏ½
οΏ½π-generation Mendel allowed F2-plant to form
seed by self-pollination called F3-generation.
Mendel observed that tall and dwarf plant behave
differently
(i) Dwarf plant produced dwarf plant on self
pollinated
(ii) In tall plants one third plants breed true so
they were pure
(iii) Other two third plant behave like parents and
give tall to dwarf plants 3 : 1 indicate that their
parents have dwarf genes also
142 (b)
Page| 76
Night blindness is nutritional deficiency disease
generally happens due to deficiency of vitamin-A
143 (a)
The genotypic ratio of monohybrid cross is 1 : 2 :
1, whereas the phenotypic ratio is 3 : 1.
9 : 3 : 3 : 1 is the phenotypic ratio of dihybrid
cross (the cross made to study the inheritance of
two pairs of factors or alleles of two genes).
144 (c)
Chromosomal Theory of Inheritance
Walter Sutton and Theodore Boveri noted that the
behavior of chromosomes was parallel to the
behaviour of genes and used chromosome
movement to explain Mendelβs laws.
Law of segregation interpreted on the basis of
genes or factors (solid and hollow) situated on
two homologous chromosomes.
Comparison between the Behaviour of
Chromosomes and Genes
Chromosomes Genes
Segregate at the
time of gamete
formation such
that only one of
each pair is
transmitted to a
gamete
Independent
pairs segregate
independently
of each other
Segregate of
gamete
formation and
only one of
each pair is
transmitted to
a gamete
One pair
segregates
independently
of another pair
Sutton and Boveri argued that the pairing and
separation of a pair of chromosomes would lead
to the segregation of a pair of factors they carried.
Sutton united the knowledge of chromosomal
segregation with Mendelian principles and called
it the chromosomal theory of inheritance.
Experimental verification of chromosomal theory
of inheritance was given by Thomas Hunt Morgan.
Morgan worked with tiny fruitfly (Drosphila
melanogaster)
145 (b)
The females have homozygous XX sex
chromosomes, while males have heterozygous XY
chromosome. Y-chromosome is shorter than X
chromosome.
146 (b)
The Downβs syndrome (Mongolian idiocy) arises
due to trisomy of 21st chromosome, i.e., total 47
chromosomes will present in such person. The
main features are mental deficiency, short stature,
round face, flaccid muscles, protruding tongue,
etc.
147 (a)
ZW-ZZ system of sex determination occurs in
certain insects (gypsy moth) and vertebrates such
as fishes, reptiles and birds and plants such as
Fragaris elatior.
148 (a)
The Sudden and heritable change in the genetic
make up of an individual is called mutation. The
term mutation was introduced by Hugo de Vries.
149 (c)
According to law of purity of gametes, when the
gametes are formed, they carry only one allele of
the gene considered.
150 (d)
The recessive trait shown by F2 and F3-generation
both but firstly it was observed in F2-generation.
Mendel cross-pollinated a pure tall pea plant
(100-120 cm hight) and a pure dwarf pea plant.
Page| 77
(only 22 to 44 cm hight). He called them parental
generation, expressed now-a-days by symbol P.
This hybridization popularly called as
monohybrid cross
This three generations of pea plants after crossing
a pure tall plant with a dwarf one. The plants of
F1-generation are all tall, of F2-generation three
tall and one dwarf. One third of the tall plants are
pure, while the remaining behave as hybrids
οΏ½
οΏ½π-generation Seeds collected from the parental
generation called first filial generation or F1
generation
οΏ½
οΏ½π-generation F1-plants pollinated among them
self (self breeding or inbreeding) and seed
produced by F1-plants called F2-generation. They
were in ratio 3:1 (three tall and one dwarf).
οΏ½
οΏ½π-generation Mendel allowed F2-plant to form
seed by self-pollination called F3-generation.
Mendel observed that tall and dwarf plant behave
differently
(i) Dwarf plant produced dwarf plant on self
pollinated
(ii) In tall plants one third plants breed true so
they were pure
(iii) Other two third plant behave like parents and
give tall to dwarf plants 3 : 1 indicate that their
parents have dwarf genes also
151 (a)
A-A; B-Genetic disorders
152 (a)
Heredity (L. Hereditas β Heirship or inheritance)
is the transmission of genetically based characters
from parents to their offspring.
The process by which characters are transferred
from one generation to the next generation is
called inheritance
153 (c)
Huntingtonβs chorea is a fatal disease of man. It is
characterized by uncontrolled jerking of body and
progressive degeneration of central nervous
system. The mean age for the onset of these
symptoms is between 35 to 40. This disease is
caused by an autosomal dominant gene.
154 (d)
Movement of chromosomes towards poles
requires centromere.
155 (a)
Klinefelterβs syndrome is represented by 44
autosomes + XXY.
157 (a)
Man has only one X-chromosomes that is inherted
to has daughter. Therefore, a heredftary disease,
which is X-chromosomal linked, is never passed
on from father to son.
159 (a)
Chromosomal theory of linkage states that
(i) Linked gene present on same chromosome
(ii) They lie in linear sequence in chromosome
(iii) There is tendency to maintain the parental
combination
(iv) Strength of linkage between two gene is
inversely proposal to the distance of two gene and
vice-versa
160 (c)
In the diploid organism (plants and animals) the
chromosome or DNA number becomes double
just before the cell division
161 (c)
Genetics is the branch of biology which deals with
the inheritance and variations
162 (c)
Balbiani first observed these chromosomes in the
salivary glands of midge Chironomus in 1881.
These polytene chromosomes are considered as
somatic giant tubules and also reported from fat
bodies some other dipterans also, e.g., Drosophila,
Chironomus, Sciaca, Rhyncosciara, etc.
163 (d)
Sir Archibald Edward Garrod was an English
physician, who pioneered the field of inborn
errors of metabolism. He was born on November
25, 1857, in London and died on March 28, 1936,
in Cambridge.
164 (c)
Page| 78
Punnett square is a table, in which all possible
combinations of gametes and progeny are
displayed in a grid structure.
165 (c)
Erythroblastosis foetalis is a haemolytic disease of
newborn children. Erythroblastosis foetalis can
occur when father is Rh positive and mother is Rh
negative. An Rh negative woman can be sensitized
when she bears an Rh+ child and Rh+ children
may have erythroblastosis.
166 (c)
When πΉ1 hybrid is crossed with its recessive
parents, it is called as test cross.By test cross, the
herterozygosity and homozygosity of the
organism can be tested. The test cross ratio in
monohybrid cross is 1 : 1 and in dihybrid cross,
ratio wii be 1 : 1 : 1 : 1.
167 (c)
Inversion involves a reverse order of genes in a
part of chromosome.
168 (b)
The gamete mother cells (2π) are called
meiocytes, which undergo meiosis to form
gametes (π) . The chromosome number in the
melocytes(2π) of housefly is 12.
169 (c)
Genes which codes for a pair a contrasting traits is
called alleles. They are slightly different forms of
the same gene, π.π., TT, tt, tT
170 (c)
Haemophilia and colour blindness are both X
linked recessive diseases. The gene for both is
found on X-chromosome only.
Albinism, Sickle-cell anaemia and thalassemia are
autosomal diseases.
171 (c)
Mendel described the inheritance of recessive and
dominant genes. Phenylketonuria (PKU) is an
autosomal recessive mutation of gene on
chromosome-12.
172 (c)
Thus, there is no dwarf plant with wrinkled seeds
in F1-generation.
173 (b)
The term genetics (Gk. Genesis=descent) was
coined by Bateson in 1906. Genetics is the study
of principles and mechanism of heredity and
variations.
174 (b)
In human beings, 46 chromosomes are found, in
which only one pair XY takes part in sex
determination. These are known as sex
chromosomes or allosomes, rest 22 pairs are
known as autosomes.
175 (a)
Mendel obtained the recessive character in F2 by
self pollinating the F1-plants.
Mendel cross-pollinated a pure tall pea plant
(100-120 cm hight) and a pure dwarf pea plant.
(only 22 to 44 cm hight). He called them parental
generation, expressed now-a-days by symbol P.
This hybridization popularly called as
monohybrid cross
This three generations of pea plants after crossing
a pure tall plant with a dwarf one. The plants of
F1-generation are all tall, of F2-generation three
tall and one dwarf. One third of the tall plants are
pure, while the remaining behave as hybrids
οΏ½
οΏ½π-generation Seeds collected from the parental
generation called first filial generation or F1
generation
οΏ½
οΏ½π-generation F1-plants pollinated among them
self (self breeding or inbreeding) and seed
Page| 79
produced by F1-plants called F2-generation. They
were in ratio 3:1 (three tall and one dwarf).
οΏ½
οΏ½π-generation Mendel allowed F2-plant to form
seed by self-pollination called F3-generation.
Mendel observed that tall and dwarf plant behave
differently
(i) Dwarf plant produced dwarf plant on self
pollinated
(ii) In tall plants one third plants breed true so
they were pure
(iii) Other two third plant behave like parents and
give tall to dwarf plants 3 : 1 indicate that their
parents have dwarf genes also
176 (a)
Criss-cross Inheritance It is a type of sex-linked
inheritance, where a parent passes the traits to
the grand child of the same sex through offspring
of the opposite sex, that is, father passes the traits
to grandson through his daughter (diagynic),
while the mother transfers traits to her grand
daughter through her son (dia-andric).
It was first studied by Morgan (1910) in case of
eye colour in Drosophila. Criss-cross inheritance
is applicable to most sex-linked disorders in
humans, π.π., red green colour blindness,
haemophilia
177 (b)
Heterozygous.
The diploid condition in which the alleles at a
given locus are identical is called homozygous or
pulls. In homozygous condition, organism have
two similar genes or alleles for a particular
character in homologous pair of chromosomes,
οΏ½
οΏ½.π., TT or tt.
Organisms containing two different alleles or
individual containing both dominant and
recessive genes of an allele pair, π.π., Tt is known
as heterozygous or hybrid
178 (c)
Mendel conducted artificial pollination/cross
pollination using true breeding pea lines A true
breeding line is one that having undergone
continuous self pollination, shows stable trait
inheritance and expression for several generation
179 (d)
Morgan and his group found that when genes
were grouped on the same chromosome, some
genes were very tightly linked (showed very low
recombination), while others were loosely linked
(showed higher recombination).
180 (b)
Polygene results in quantitative inheritance,
which is characterized by occurrence of
intermediate forms between the parental type. In
case of crossing between AABBCC (dark colour)
and aabbcc (light colour), in πΉ2-generation seven
phenotypes will obtain with ratio 1 : 6 : 15 : 20 :
15 : 6 : 1. The total number of progeny is 64, out of
which only two will be likely resemble with either
parents. Hence, their proportion in πΉ2-generation
would be 3.12, i.e., less than 5%
181 (a)
In cancer cells there is uncontrolled cell division.
In them chromosomal abbreviation is commonly
found
182 (b)
The given case is the example of codominance.
183 (d)
Males and female are haemophilic definately. If
their father and mother both are haemophilic
184 (b)
Polyploidy is the phenomenon, which leads to
increase in the number of chromosomes thus,
increasing in the number of genes. Due to
cumulative effect of genes, new characters appear,
which results into formation of new species.
185 (b)
Mendel is called father of genetics. There are three
laws of Mendel in respect of inheritance:
- Law of dominance
- Law of segregation or Law of purity of
gametes or Law of splitting of hybrids. - Law of independent assortment
186 (b)
Page| 80
Test cross is a cross between πΉ1 hybrid with its
recessive parent.
187 (a)
Homogametic.
XY and XY type sex determination seen in many
insect and mammals including humans. Males
have X and Y chromosome along with autosome
and females have pair of βXβ chromosome along
with autosome
Parents Phenotypes Male
Female
Genotypes 44A + XY
44A + XX
Gametes 22A + X 22A+Y
22A + A22A + X
22A+ X 22A+X
Children 22A + X 44A + XX 44 A + XY
Female
22A + Y 44 A + XY 44 A + XY
Male
Sex ratio Female : Male = 1 : 1
In plants The flowering plants are mostly bisexual
and lack sex chromosomes. The unisexual
flowering plants tent to have XX-XY type of sex
chromosomal mechanism for sex determination.
The female plants are XX and male plants are XY.
XX and XO Type of Sex Determination
Found in insect like grasshopper, cockroaches and
bugs. Males have only X sex-chromosome and
autosomes, female have pair of X-chromosome
and autosome
Parents Phenotypes Male Female
Genotypes π΄π΄+ππ π΄π΄+ππ
Gametes π΄+π,π΄+π π΄+π,π΄+π
οΏ½
οΏ½π-generation
XX-XO type of sex determination
In most of cases the female produce similar sex
chromosome called homomorphic. In most of
cases the male produce dissimilar sex
chromosome called hetermorphic
188 (a)
In birds, usually female is designated as ZW, being
heterogametic and male is designated as ZZ being
homogametic.
189 (a)
A cross of round yellow seeds (both dominant)
and green wrinkled seed (both recessive) plants
produced 9 : 3 : 3 : 1 ratio of plants
(phenotypic)in πΉ2 generation. The ratio of
parental to recombinant is 10 : 6 here because the
9 and 1 are of parental type and 3 & 3 are
recombinant.
190 (a)
In genetics, a test cross, first introduced by Gregor
Johann Mendel, is used to determine weather an
individual exhibiting a dominant trait is
homozygous or heterozygous for that traits. More
simply, test cross determines the genotype of an
individual with a dominant phenotype. The test
cross is defind as being a type of back cross
between the recessive homozygote parents and πΉ1
generation.
191 (c)
So, all sons in the progeny will be normal.
192 (d)
When a tall pea plant (TT) is crossed with dwarf
plant (tt), the F1progeny shows all plants hybrid
tall and on selfing of F1progeny, the F2generation
shows both tall and dwarf plant in the ratio 3 : 1.
Out of three tall plants, one is pure tall (TT) and
two are hybrid tall (Tt).
193 (c)
A-Two, B-Chromosomal, C-Mutation
194 (c)
A-Heterozygous, B-Unaffected, C-Carrier
196 (c)
Linkage group will be equal to haploid number of
chromosomes. πππ π’π π ππ‘ππ£π’π has seven pairs of
chromosomes, therefore linkage group is also
seven.
197 (d)
Page| 81
When a cross (dihybrid) is made between plants
bearing round yellow (RRYY) and wrinkled green
(rryy) seeds, all the plants in F1-generation are
with yellow round seeds (showing the genotype
RrYy).
198 (a)
Black colour is dominant over the recessive so by
cross it is easily infered that 75% of the offspring
are black and 25% are brown
199 (b)
There are only very few characters, which are
present on the Y-chromosome of male. Like
hypertrichosis. Given pedigree analysis is the
example of Y-linked inheritance because all male
progeny is affected
200 (a)
Haemophilia.
Genetic or chromosomal symbol used for person
who is having sickle-cell anaemia PsβHbs Hbs.
Sickle-cell Anaemia
(i) It is an autosome-linked recessive trait
(ii) The disease is controlled by a single pair of
allele Hbs and Hbs
(iii) Only the homozygous individuals for Hbs, i.e.,
HbsHbs show the diseased phenotype
(iv) The heterozygous individuals are carriers
(HbAHbS)
(v) Due to point mutation, glutamic acid (Glu) is
replaced by valine (Val) at the sixth position of Ξ²
globin chain of haemoglobin molecule
(vi) A single base substitution at sixth codon of
the beta globulin gene from GAG to GUG. GAG
code for glutamic acid and GUG code for valine.
(vii) HbS behaves as normal haemoglobin except
under the oxygen stress where erythrocytes lose
their circular shape and become sickle-shaped. As
a result, the cells cannot pass through narrow
capillaries. Blood capillaries are clogged and thus,
affect blood supply to different organs
omal
dominant in males and autosomal recessive in
females
(iii) Sex Influenced Traits The traits are not due to
particular genes but are by products of sex
hormones, e.g., low pitched voice, beard
moustaches. In males, pattern baldness is related
to both autosomal genes as well as excessive
secretion of testosterone
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