Class 8 Science Chapter 8 Adolescence Oxford Book

Class 8 Science Chapter 8 Adolescence Oxford

II. Very short answer type questions

A. Give one word for the following:

  1. The chemical substances secreted by the glands
    Hormones
  2. Specialized organs that secrete particular chemical substances
    Glands
  3. The master gland
    Pituitary gland
  4. The period of transition from childhood to adulthood
    Adolescence
  5. The process of release of a mature ovum by an ovary
    Ovulation
  6. Chemical substances that produce physical, mental, and emotional changes in a user
    Drugs
  7. The cycle of producing and releasing a mature ova
    Menstrual cycle
  8. An adolescent girl’s first menstruation
    Menarche

III. Short Answer Type Questions

  1. What are hormones?
    Hormones are chemical messengers produced by glands in the body. They travel through the blood and regulate various functions like growth, metabolism, and reproduction.
  2. Name any five glands of the human endocrine system.
    Pituitary gland, thyroid gland, adrenal gland, pancreas, ovaries (in females) / testes (in males).
  3. Why is the adrenal gland known as the emergency gland?
    Because it produces hormones like adrenaline that prepare the body to face emergencies by increasing heart rate, blood flow, and energy.
  4. Define adolescence.
    Adolescence is the period of life when a child develops into an adult, marked by physical, emotional, and psychological changes.
  5. What is menarche? How is it different from menopause?
    Menarche is a girl’s first menstrual period, marking the start of reproductive capability. Menopause is the time when menstruation stops permanently, usually in middle age.
  6. Name the hormones that bring about changes during adolescence in girls.
    Estrogen and progesterone.
  7. What are drugs? Give two common examples of drugs.
    Drugs are chemical substances that affect the body or mind. Examples: Alcohol and tobacco.
  8. Define drug abuse.
    Drug abuse is the harmful or excessive use of drugs that negatively affects health and life.

IV. Long Answer Type Questions

  1. Explain the main glands of the endocrine system with the hormones and the role each of them plays in the human body.
    1. Pituitary gland: Called the master gland, it controls other glands and regulates growth hormone and reproductive hormones.
    1. Thyroid gland: Produces thyroxine, which regulates metabolism and growth.
    1. Adrenal gland: Produces adrenaline, helping the body respond to stress or emergencies.
    1. Pancreas: Produces insulin, which controls blood sugar levels.
    1. Ovaries (in females): Produce estrogen and progesterone, regulating menstrual cycle and reproductive functions.
    1. Testes (in males): Produce testosterone, responsible for male sexual development.
  2. Define puberty. Discuss some physical changes that boys and girls undergo during puberty.

Puberty and Physical Changes in Boys and Girls

Definition of Puberty:
Puberty is the stage in life when a child’s body develops into an adult body capable of reproduction. It happens due to the production of special hormones in the body.

Physical Changes During Puberty:

In Boys:

  • Voice becomes deeper.
  • Growth of facial, pubic, and body hair.
  • Increase in height and muscle strength.
  • Enlargement of testes and penis.
  • Production of sperm begins.

In Girls:

  • Breasts start to develop.
  • Hips widen and body shape changes.
  • Growth of pubic and underarm hair.
  • Onset of menstruation (periods) begins.
  • Increase in height and body fat in certain areas.

These changes help boys and girls become physically mature and ready for adult life.

  • With the help of a labelled diagram, explain the menstrual cycle in adolescent girls.

The Menstrual Cycle in Adolescent Girls

The menstrual cycle is a monthly process that prepares the girl’s body for pregnancy. It usually lasts about 28 days and involves changes in the ovaries and the uterus.

Explanation:

  • Day 1 to 5 – Menstruation:
    The old lining of the uterus (called the endometrium) breaks down and comes out as menstrual blood through the vagina. This is called the period or menstruation.
  • Day 6 to 13 – Follicular Phase:
    A hormone causes an egg (ovum) to start maturing inside a small sac called a follicle in the ovary. At the same time, the uterus starts to build a new lining to prepare for a fertilized egg.
  • Day 14 – Ovulation:
    The mature egg is released from the ovary into the fallopian tube. This is called ovulation and is the time when a girl is most fertile.
  • Day 15 to 28 – Luteal Phase:
    The uterus lining becomes thick and spongy to support a possible pregnancy. If the egg is not fertilized, hormone levels drop, causing the lining to break down, and the cycle starts again with menstruation.
  • Discuss some of the emotional changes that boys and girls go through during adolescence.

Ans: Emotional Changes During Adolescence

During adolescence, both boys and girls experience many emotional changes because of hormonal shifts and physical development. Some common emotional changes include:

  • Mood swings: Teens may feel happy one moment and upset the next without a clear reason.
  • Increased sensitivity: They become more sensitive to comments and situations, sometimes feeling hurt easily.
  • Confusion and frustration: Adolescents often struggle to understand their feelings and may feel confused about their identity or future.
  • Desire for independence: They want to make their own decisions and may challenge parental authority.
  • Self-consciousness: Teens become more aware of their appearance and what others think of them, leading to feelings of shyness or embarrassment.
  • Stronger emotions: They may experience intense feelings of love, anger, or sadness for the first time.

These emotional changes are a normal part of growing up and help adolescents develop their own personality and social skills.

  • Write a note on the nutritional requirements and personal hygiene needed by girls during adolescence.

Ans: Nutritional Requirements and Personal Hygiene for Girls During Adolescence

During adolescence, girls undergo many physical changes and need a balanced diet rich in proteins, calcium, iron, vitamins, and water to support growth and maintain health. Proteins help build muscles, calcium strengthens bones, and iron prevents anemia caused by menstruation.

Personal hygiene is very important to prevent infections. Girls should bathe regularly, use clean sanitary products during menstruation, change them frequently, and wear clean clothes. Good hygiene also includes brushing teeth, washing hands, and taking care of hair.

Proper nutrition and hygiene help girls stay healthy, feel confident, and cope well with the changes during adolescence.

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Class 8: Class 8 Science Chapter 8 Adolescence Oxford and NCERT Solutions Explore below

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The topic of adolescence is crucial for young learners, and the Class 8 Science Chapter 8 Adolescence Oxford Book provides a comprehensive introduction to the physical and emotional changes that occur during this stage.

Our explanations are designed to support the content of the Class 8 Science Chapter 8 Adolescence Oxford Book, making it easier for students to grasp complex ideas such as hormonal changes, growth patterns, and mental health awareness. By studying the Class 8 Science Chapter 8 Adolescence Oxford Book, students can better understand how their bodies change and why these changes happen. The solutions and guidance offered are aligned closely with the Class 8 Science Chapter 8 Adolescence Oxford Book, helping learners feel more confident in both academics and self-awareness. Overall, revisiting the Class 8 Science Chapter 8 Adolescence Oxford Book regularly will reinforce important life skills and scientific knowledge for every student.