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NEET MCQs Reproduction in Organisms [Free PDF Download]

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, 𝐴𝑚𝑜𝑒𝑏𝑎 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 𝐶ℎ𝑙𝑎𝑚𝑦𝑑𝑜𝑚𝑜𝑛𝑎𝑠
b. Conidia of 𝑃𝑒𝑛𝑖𝑐𝑖𝑙𝑙𝑖𝑢𝑚
c. Buds in 𝐻𝑦𝑑𝑟𝑎
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
𝐵𝑟𝑦𝑜𝑝ℎ𝑦𝑙𝑙𝑢𝑚 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 𝑃𝑖𝑠𝑡𝑖𝑎 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. 𝑆𝑡𝑟𝑜𝑏𝑖𝑙𝑎𝑛𝑡ℎ𝑢𝑠 𝑘𝑢𝑛𝑡ℎ𝑖𝑎𝑛𝑎 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 “eyes” 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) 𝐵𝑟𝑦𝑜𝑝ℎ𝑦𝑙𝑙𝑢𝑚 c) Rose d) 𝐷𝑢𝑟𝑎𝑛𝑡𝑎
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 𝑜𝑓 𝐻𝑖𝑏𝑖𝑠𝑐𝑢𝑠 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
‘Bisexual animals that possess both male and female reproductive organs are called hermaphrodite’. 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) 𝐵𝑟𝑦𝑜𝑝ℎ𝑦𝑙𝑙𝑢𝑚 c) 𝐼𝑝𝑜𝑚𝑒𝑎 d) 𝑅ℎ𝑖𝑧𝑜𝑝ℎ𝑜𝑟𝑎
Vegetative propagation in 𝑃𝑖𝑠𝑡𝑖𝑎 occurs by:
a) Stolon b) Offset c) Runner d) Sucker
𝑅ℎ𝑖𝑧𝑜𝑝𝑢𝑠 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 organism’s 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 → new individual → zygote
b) Fusion of gametes → zygote → new individual (cell 2𝑛)
c) Fission of gametes → zygote → new individual (cell 2𝑛)
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

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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 Mendel’s law of inheritance called
a) Mendelian disorder b) Chromosomal disorder
c) Maternal inheritance d) Polygenic inheritance
The term ‘gene’ was coined by
a) Avery b) Bateson c) Johanssen d) Mendel
The phenotypic ratio in the 𝐹2 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 …A… stage of cell division results in an increase in a whole set of chromosomes
in an organism called …B…
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) RRYY×rryy b) RRYY×rryy c) RRYY×Rryy d) RrYy×rryy
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 …A… . Complete linkage is …B… . 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 Mendel’s investigation, it was first time that …A… and …B… 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 𝐴,𝐵 and 𝐶 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 Turner’s 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 𝐹2generation?
a) Histones b) Hydrocarbons c) Polynucleotides d) Lipoproteins
Examples of dissimilar sex chromosomes are given below
I. XX – XY ⇒ I
II. XX – XO ⇒ 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 𝐹1generation has all tall, and 𝐹2ratio is 3 : 1, it proves
a) Law of dominance b) Independent assortment
c) Law of segregation d) linkage
Mendel’s 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 𝐹2generation 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 –A may inherit the genes for blonde hair, while other individuals with
blood group – 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 …A… separate and pass into two daughter nuclei and cells during mitosis. Similarly, each …B…
replicates, with one pair passing into each daughter cell during mitosis. This maintains the similar …C… 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 𝐹1
dihybrid b) Homozygous condition of the 𝐹1-dihybrid
c) Four different types of 𝐹1-dihybrids d) Four different types of gametes produed by the
�
�1-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) BB×AA b) AB×AB c) BO×OO d) BO×AO
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) 2𝑛−1+1 b) 2𝑛−1−1 c) 2𝑛−1 d) 2𝑛+1+1
Which is a sex-influenced disease?
a) Baldness in male b) Haemophilia
c) Xeroderma pigmentosa d) Down’s 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
𝑁𝑖𝑐𝑜𝑡𝑖𝑎𝑛𝑎 𝑠𝑦𝑙𝑣𝑒𝑠𝑡𝑟𝑖𝑠 flowers only during long days and 𝑁.𝑡𝑎𝑏𝑎𝑐𝑢𝑚 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
Down’s syndrome and Turner’s 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) Turner’s syndrome
Which of the following is not true of haemophilia?
a) Royal disease b) Bleeder’s 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) 𝛼−𝑟𝑎𝑦𝑠 b) β−𝑟𝑎𝑦𝑠 c) 𝛾−𝑟𝑎𝑦𝑠 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) Down’s syndrome b) Klinefelter’s syndrome
c) Turner’s 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, Huntington’s 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

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The arrangement of genes on chromosome is
a) Linear b) Oviod c) Diffused d) Spiral
When two genetic loci produce identical phenotypes in 𝑐𝑖𝑠 and 𝑡𝑟𝑎𝑛𝑠 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 –II – Thromboplastin b) Factor –III – Prothrombin
c) Factor –VIII – Antihaemophilic globulin d) Factor –XII – Haemophilic
The longest chromosomes is seen in
a) Allium b) Lilium c) Trillium d) Zea mays
Mendel observed that ….. generation shows always phenotype of dominant parent
a) F4 b) F2 c) F1 d) F0
…A… genes are those which occurs on the same chromosome and …B… 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 …A… rare because mother of such a female has to be
at least …B… and the father should be …C…
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 Rh−, 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 ‘O’
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 only−either anti-a or anti–b 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) Can’t be determined

NEET MCQs: Inheritance & Variation Page| 8

Sickle –cell 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 𝐴,𝐵,𝐶 and 𝐷 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 Sidd’s 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 Shepherd’s 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 𝐷𝑟𝑜𝑠𝑜𝑝ℎ𝑖𝑙𝑎 , 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 𝐹2generation?
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 vitamin–K b) Blood platelets and haemoglobin
c) Lack of clotting material and vitamin-K d) All of the above
All of this obeys Mendel’s laws except
a) Codominance b) Independent assortment
c) Dominance d) Purity of gametes
in β-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 𝐹1generation?
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
Mendel’s 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 – viable progeny, the factor responsible for
such conditions are
a) Polygenes b) Linked genes c) Lethal genes d) Epistatic genes
Turner’s 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 𝐹2-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 𝐹2-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 Down’s 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- …A… but colour blindness can’t be cured because it is
…B… 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 Huntington’s disease is true?
a) Genetic tests to detect the presence of the allele responsible for Huntington’s disease do not exist at this
time
b) The onset of Huntington’s disease is typically between birth and three years of age
c) There is currently no effective treatment of Huntington’s disease
d) Huntington’s 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) Klinefelter’s syndrome –44 autosomes + XXY b) Colour blindness –Y- linked
c) Erythroblastosis foetalis –X- linked d) Down’ s syndrome – 44 autosomes+ XO
Rrrr progeny : Red (dominant) flowered heterozygous crossed with white flower
a) 350→red∶350→white b) 450→red∶250→white
c) 380→red∶250→white 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) Turner’s 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) Down’s syndrome b) Turner’s syndrome

Page| 13

c) Phenylketonuria d) Klinefelter’s syndrome

When a tall plant with round seeds (TTRR) crossed with a dwarf plant with wrinkled seeds (ttrr), the 𝐹1
generation consists of tall plants with round seeds. What would be the proportion of dwarf plant with
wrinkled seeds in 𝐹1-generation?
a) 1
4 b) 1
16 c) 0 d) 1
2
The term ‘Genetics’ 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 …A… the …B… plants. Here 𝐴 and 𝐵 refers to
a) A-self-pollinating; B−F1 b) A-self-pollinating; B−F2
c) A-cross-pollinating; B−F1 d) A-cross-pollinating; B−F2
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

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)×aabbcc(light colour) , in 𝐹2 generation. What proportion of the progeny is likely to
resemble either parent?
a) Half b) Less than 5 per cent c) One –third 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) Hybrid×Dominant parent b) Hybrid×Recessive parent
c) Hybrid×Hybrid 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 𝐹2 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 …A… group Mendelian disorder and …B… disorders.
Mendelian disorder are mainly determined by …C… 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
…A… individual show …B… phenotype but they are the …C… 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 Mendel’s 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 RRYY×rryy?
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 :

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. 𝑒.𝑔.,
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, 𝑒.𝑔., Turner’s syndrome, Down’s
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 𝐹1 generation shows hybrids with
dominant phenotypic effect. When 𝐹1
heterozygous plants are self-ferilized to
produce𝐹2 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 𝐹2 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 𝐹1 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 ‘X’ 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)

Page| 60

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 presen’t in an organisms. It only
happens when cytokinesis doesn’t 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 RrYy×rryy.
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, 𝑒.𝑔., 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, 𝑒.𝑔., epistasis, duplicate
genes, complementary genes, supplementary
genes, lethal genes, inhibitory genes, etc.
20 (c)

Page| 61

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, ‘Tall’ character is
dominant over ‘dwarf’, 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 ‘X’ 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 𝐴𝐴+𝑋𝑂 𝐴𝐴+𝑋𝑋
Gametes 𝐴+𝑋,𝐴+𝑂 𝐴+𝑋,𝐴+𝑌
�
�𝟏-generation

XX-XO type of sex determination
29 (c)
Female is sterile.
Disorders Autosomal/Sex
Linked
Symptoms Effects
Down’s
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)
Turner’s
syndrome
Sex
chromosomal
monosomy 44

XO
Short stature
females (<5’),
webbed neck, body
hair absent
menstrual cycle
absent. Sparse
pubic hair,
underdeveloped
breasts narrow lips
puffy fingers
Sterile
hearing
problem
Klinefelter’s
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) Down’s 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) Turner’s syndrome

Page| 63

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) Klinefelter’s 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 ‘X’ 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 𝐴𝐴+𝑋𝑂 𝐴𝐴+𝑋𝑋
Gametes 𝐴+𝑋,𝐴+𝑂 𝐴+𝑋,𝐴+𝑌
�
�𝟏-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 𝐹1 generation. By selfing of these 𝐹1
plants tall and dwarf plants produced in 3 : 1
ratio.
36 (b)
Mendel’s 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 𝐹2
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 –a-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
�
�𝟏-generation

ZO-ZZ type of sex determination
43 (c)
Mendel’s law of independent assortment states
that,”the alleles of different genes segregate
independently of each other during meiosis”.
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 ‘X’ 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 𝐴𝐴+𝑋𝑂 𝐴𝐴+𝑋𝑋
Gametes 𝐴+𝑋,𝐴+𝑂 𝐴+𝑋,𝐴+𝑌
�
�𝟏-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
‘chromosomal’ theory of linkage’
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 ‘science of being well
born’.
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 𝐹1-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 BO×AO.
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

𝛂-thalassaemia Production of α-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.

𝛃-thalassaemia Production of β-globin
chain is affected. It occurs due to mutation
of one or both HBB genes on chromosome
11
60 (a)
The term ‘mutation’ 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 doesn’t 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
(𝑁𝑖𝑐𝑜𝑡𝑖𝑎𝑛𝑎) has two different species,
�
�𝑖𝑐𝑜𝑡𝑖𝑎𝑛𝑎 𝑡𝑜𝑏𝑎𝑐𝑐𝑢𝑚 and 𝑁𝑖𝑐𝑜𝑡𝑖𝑎𝑛𝑎 𝑠𝑦𝑙𝑣𝑒𝑠𝑡𝑟𝑖𝑠.
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=2𝑛
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
formula2𝑛+1 . One of the pairs of chromosomes
has an extra member, so that a trivalent may be
formed during meiotic prophase, e.g., Down’s
syndrome (45+XX or 45+XY), Klinefelter’s
syndrome (44 + XXY).
In monosomic, diploid organism has one
chromosome of a single pair missing with
genomic formula 2𝑛−1. Monosomics can from
two kind of gametes, (n) and (n-1),
e.g., Turner’s syndrome (44 + X).
70 (d)

Page| 67

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).
Turner’s 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) × (Homozygous dwarf)

Phenotypic ratio 1 : 1 (50% tall, 50% dwarf)
Genotypic ratio 1 : 1
75 (c)
γ−rays 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 don’t 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

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