Class 8 Science Chapter 7 Practice Question Answers - Reaching the Age of Adolescence

Q1: What is Adam’s apple?
Ans: The protruding part of the throat in males is called Adam’s apple.

Q2: Name the hormone in female that is produced by ovaries and helps in development of mammary glands.
Ans: Estrogen

Q3: Whose height grow faster initially—boys or girls?
Ans: Girls

Q4: Name a gland which transports secretions through ducts.
Ans: Sweat glands/salivary glands/ oil gland (any one).

Q5: What is puberty?
Ans: The age at which boys and girls become capable of reproduction.

Q6: What are hormones?
Ans: The chemical substances produced by endocrine glands are called hormones.

Q7: How long is a woman’s reproductive life lasts?
Ans: Menarche to menopause.

Q8: Name the female hormone.
Ans: Estrogen

Q9: ___________ means to grow into maturity.
Ans: Adolescence

Q10: Children gain height during ___________.
Ans: puberty

Q11: The boys and girls passing through the adolescence period are called ___________ or ___________.
Ans: adolescents, teenagers

Q12: During puberty, a change in voice takes place due to the increase in the size of ___________ or ___________.
Ans: voice box, larynx

Q13: The stage when the menstrual cycle stops is called ___________.
Ans: menopause

Q14: The ___________ gland helps in controlling the production of both testosterone and estrogen hormones.
Ans: pituitary

Q15: The number of chromosomes present in human cell are
(a) 25 pairs
(b) 22 pairs
(c) 23 pairs
(d) none of these
Ans: (c)
Explanation: Humans have a total of 46 chromosomes in their cells, organized into 23 pairs. These pairs consist of 22 pairs of autosomes (non-sex chromosomes) and 1 pair of sex chromosomes.

Q16: The number of sex chromosomes are
(a) three
(b) two
(c) four
(d) none of these
Ans: (b)
Explanation: Humans have two sex chromosomes that determine an individual's sex. Males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).

Q17: The age of menopause stage is
(a) 45 to 50 years
(b) 40 to 45 years
(c) 50 to 55 years
(d) none of these
Ans: (c)
Explanation: Menopause is the stage in a woman's life when she stops having menstrual periods and is no longer able to conceive children. The average age range for menopause is typically between 50 to 55 years.

Q18: The unfertilised egg always has __________ chromosome
(a) X
(b) Y
(c) XY
(d) XX
Ans: (a)
Explanation: Unfertilized eggs (ova) always contain one X chromosome. The sperm contributes either an X or a Y chromosome during fertilization, determining the sex of the offspring.

Q19: A female has
(a) XY chromosomes
(b) YY chromosomes
(c) XX chromosomes
(d) none of these
Ans: (c)
Explanation: A female typically has two X chromosomes (XX). The presence of two X chromosomes determines the female sex and various genetic traits associated with females.

Value-Based Questions

Q20: Salma had a very soft and smooth skin during her childhood. As she entered adolescence, she developed pimples on her face, her body became taller compared to her face. She got worried of all of the sudden changes. Her mother explained that all these changes are normal and advised her to wash her face at regular intervals.

1. Why Salma’s mother advised Salma to wash her face at regular intervals?
2. What is the reason for appearance of pimples on her face?
3. Why Salma experienced disproportionate growth of the body?
4. What values do we get from this?

Ans:

1. Regular face wash keeps the face clean and dry and helps to reduce the pimples.
2. During adolescence, secretion of sweat glands and sebaceous glands increases leading to formation of acne and pimples.
3. During adolescence, all parts of the body do not grow at the same rate. Sometimes the arms and legs or hands and feet of adolescents look oversized and out of proportion with the body.
4. We must be self-aware, must take proper care and diet during the growing period, not get worried or lose our self-esteem.