the Age of Adolescence
Q22. Who attains puberty at an earlier age in human beings: boys
Ans. In girls, adolescence may begin a year or two
earlier than in boys.
Q23. What is the most conspicuous change during puberty?
most conspicuous change during puberty is the sudden increase in height.
Q24. What is the legal age for marriage of boys and girls in our
Ans. In our country, the legal age for marriage is 18
years for girls and 21 years for boys.
Q25. How do hips of girls change during puberty?
Ans. Girls develop broader hips during puberty. Due to
this, region below the waist becomes wider.
Q26. State the age at which adolescence usually begins and the
age up to which it lasts.
At what age adolescence usually begins and up to which it lasts?
Ans. Adolescence begins around the age of 11 and lasts
up to 18 or 19 years of age.
Q27. Why endocrine glands are called ductless glands?
Ans. Endocrine glands release hormones directly
into the bloodstream. So, they are also termed ductless glands.
Q28. Which hormone is responsible for metamorphosis in frog?
Ans. In a frog, metamorphosis is controlled by
thyroxine, the hormone produced by thyroid.
Q29. Which two male sex organs develop completely at puberty?
Ans. At puberty, male sex organs like the testes and
penis develop completely. The testes also begin to produce
Q30. Which two female sex organs develop completely at puberty?
Ans. In girls,
the ovaries enlarge and eggs begin to mature. Also ovaries start releasing mature eggs.
Q31. What is puberty?
Ans. The period during which adolescent boys and girls
reach sexual maturity and become capable of reproduction is called puberty.
Q32. What are hormones? Where are hormones made in the human body?
Ans. Hormones are chemical substances. These are
secretions from endocrine glands, or endocrine system.
Q33. What is the function of adrenalin hormone in the body?
Ans. Adrenals also produce the hormone adrenalin. It
helps the body to adjust to stress when one is very angry, embarrassed or
Q34. Name the time period in one's life when the brain has the
greatest capacity for learning.
Ans. Adolescence is often the time in one’s life when
the brain has the greatest capacity for learning.
Q35. Which disease is caused by the insufficient production of
insulin hormone by pancreas?
Ans. Diabetes is caused by the insufficient production
of insulin hormone by pancreas.
Q36. Which endocrine gland secretes hormone that maintains
correct salt balance in the blood?
Ans. Adrenal glands secrete hormones which maintain
the correct salt balance in the blood.
Q37. Why is exercise important during adolescence?
Ans. Walking and playing in fresh air keeps the body
fit and healthy. Thus, all young boys and girls should take walks, exercise and
play outdoor games.
Q38. What is the effect of a smaller voice box in grown up girls?
Ans. In girls, the larynx is hardly visible from the
outside because of its small size. The smaller voice box in girls gives shrill
voice or high pitched voice to the girls.
Q39. Why is iron mineral important for our body? Write some iron
Ans. Iron mineral is important for our body because it
builds blood. Iron-rich food includes leafy vegetables, jaggery, meat, citrus,
Indian gooseberry (amla) etc.