Reaching the age of adolescence is a chapter in class 8 science book. This chapter talks about the changes that occurs in the body of both females and males during the time of puberty. Various hormones which are formed in our body and the functions of each hormone.
Reaching the Age of Adolescence NCERT Solutions
Question 1. What is the term used for chemical secretions of endocrine glands responsible for changes taking place in the body?
Ans 1:Hormones are secreted by endocrine glands. Different hormones have different functions.
Question 2: Define Adolescence
Ans 2: Adolescence is the stage between puberty and adulthood. A lot of physical changes takes place in the human beings during this stage. This stage occurs between the age of 12 to 18 years.
Question 3: What is menstruation? Explain
Ans 3: Menstruation is the process in which the inner lining of the uterus. Basically the female body prepares for the fertilization of the egg. To provide nutrition to the embryo, blood is supplied to the lining. When no fertilization of this egg takes place, then the inner lining of the uterus breaks and comes out through the vagina in the form of blood. This is partial blood and tissues from the uterus.
Question 4: List the changes in the body that takes place at puberty.
Different changes occurs during puberty in both males and females
In boys the chest becomes broad and the voice becomes lower.
The testicles and the penis starts growing.
Pubic hairs starts growing in both males and females.
In girls, ovary starts maturing and the breasts start developing.
The weight of the body changes in both males and females.
Pimples start coming on the face in case of both girls and boys.
Question 5 Prepare a table showing the endocrine glands and the hormones.
Ans 5:
Endocrine Glands Hormones
Testis Testosterone
Pancreas Insulin
Thyroid Thyroxine
Pituitary Growth hormone
Ovary Estrogen
Question 6: What are sex hormones? Why are they named so? State their function
Ans 6: Hormones are chemical substances secreted by an endocrine gland. Sex organs are secreted in both male and females.
Sex hormones produced in males is testosterone. It provides secondary sexual characteristics to males. Growth of reproductive organs in males, change in voice etc
In females the sex hormone released is known as Oestrogen. The changes that occur in the female’s body due to this hormone is development of the breasts, and the growth of reproductive organs.
Question 7: Choose the correct option.
(a) Adolescents should be careful about what they eat, because
(i) proper diet develops their brains.
(ii) a proper diet is needed for the rapid growth taking place in their body.
(iii) adolescents feel hungry all the time.
(iv) taste buds are well developed in teenagers.
Ans ( ii) a proper diet is needed for the rapid growth taking place in their body.
(b) Reproductive age in women starts when their
(i) menstruation starts.
(ii) breasts start developing.
(iii) body weight increases.
(iv) height increases.
Ans b) menstruation starts
(c) The right meal for adolescents consists of
(i) chips, noodles, coke.
(ii) chapati, dal, vegetables.
(iii) rice, noodles and burger.
(iv) vegetable cutlets, chips and lemon drink.
Ans (c) chapati, dal, vegetables.
Question 8: Write notes on—
(a) Adam’s apple.
(b) Secondary sexual characters.
(c) Sex determination in the unborn baby.
Ans 8:
(a) Adam’s apple develops in the age of puberty. The size of the larynx grows and it projects outwards in case of boys. The voice becomes heavy. In female’s the voice becomes high pitched.
(b) Secondary sexual characters occurs at the time of puberty in both boys and girls. Some of the sexual characteristics that occur are enlargement of breasts in females, enlargement of penis in boys, pubic hair growth under arms pits and around reproductive organs. Moustaches starts growing in case of boys.
(c) Sex determination in the unborn baby can be done by knowing about the chromosomes in the new born. Each organism has 23 pairs of chromosomes. Out of these pairs one is the sex chromosome. A female shows both X chromosomes, while a male has one X and one Y chromosome. If the newborn baby has both X chromosome then it will be a girl and if it has one X and one Y it will be male.
9. Word game :
Use the clues to work out the words.
Across
3. Protruding voice box in boys
4. Glands without ducts
7. Endocrine gland attached to brain
8. Secretion of endocrine glands
9. Pancreatic hormone
10. Female hormone
Down
1. Male hormone
2. Secretes thyroxine
3. Another term for teenage
5. Hormone reaches here through blood stream
6. Voice box
7. Term for changes at adolescence
Ans 9)
Across
3. Adam’s Apple
4. Endocrine
7.Pituitary
8. Hormone
9. Insulin
10. Estrogen
Down
1.Testosterone hormone
2.Thyroid gland
3. Adolescence
5. Target site
6. Larynx
7. Puberty
So, these were the solutions for chapter 10 of Class 8 NCERT Science book, Reaching the age of adolescence. Hope you find these answers useful. Stay connected with Careeradvice4u for more NCERT Solutions for classes 6, 7, 8, 9, and 10. This was Deepak Kumar here. Feel free to ask me any queries related to this chapter.
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