1)What is the term used for secretions of endocrine glands
responsible for changes taking place in the body?
responsible for changes taking place in the body?
ANSWER:- Hormones
2)Define adolescence.
ANSWER:-Adolescence
is the time period between the beginning of puberty and adulthood. During this
period, the body undergoes several changes alongside reproductive maturity.
is the time period between the beginning of puberty and adulthood. During this
period, the body undergoes several changes alongside reproductive maturity.
3)What is menstruation? Explain.
ANSWER:-Menstruation is the process of the shedding of
the uterine lining on a regular monthly basis. It
begins at puberty and is the reproductive cycle of the female body. Every
month, the uterus prepares itself to receive a fertilized egg.
the uterine lining on a regular monthly basis. It
begins at puberty and is the reproductive cycle of the female body. Every
month, the uterus prepares itself to receive a fertilized egg.
Therefore, the inner lining of the uterus becomes thick and is
supplied with blood to nourish the embryo. If the egg is not fertilized, then
the lining of the uterus breaks down and gets released in the form of blood through the vagina. This
lasts for about two to eight days. This cycle occurs every month and is known
as the menstrual cycle.
supplied with blood to nourish the embryo. If the egg is not fertilized, then
the lining of the uterus breaks down and gets released in the form of blood through the vagina. This
lasts for about two to eight days. This cycle occurs every month and is known
as the menstrual cycle.
4)List changes in the body that take place at puberty.
ANSWER:-Changes at puberty:
(i) Sudden increase in height and weight.
(ii) Broadening of shoulders and widening of chest in boys. In
girls, the region below waist becomes wider.
girls, the region below waist becomes wider.
(iii) In boys, under the influence of hormones, the larynx becomes
prominent, the vocal cords become
longer and thicker. These changes cause the voice to become hoarse.
prominent, the vocal cords become
longer and thicker. These changes cause the voice to become hoarse.
(iv) Appearance of hair in areas such as underarms, face, hands,
and legs.
and legs.
(v)Reproductive organs begin to mature.
5)Prepare a Table having two columns depicting names of
endocrine glands and hormones secreted by them.
endocrine glands and hormones secreted by them.
ANSWER:-
Endocrine gland Hormones
Testis.
Testosterone
Testosterone
Ovary Oestrogen
Thyroid Thyroxin
Adrenal Adrenalin
Pancreas. Insulin
Pituitary. Growth hormone
6)What are sex hormones? Why are they named so? State their
function.
function.
ANSWER: – Sex hormones are chemical substances produced by sex organs. For
example,
testosterone is the male sex hormone produced by the
testis, and oestrogen is the female sex hormone
produced by the ovary.
example,
testosterone is the male sex hormone produced by the
testis, and oestrogen is the female sex hormone
produced by the ovary.
These hormones affect the sexual features of an organism. Hence,
they are known as sex hormones.
they are known as sex hormones.
Functions of sex hormones:
Testosterone: This hormone brings
about secondary sex characters in boys such as the
growth of a beard, the voice becoming hoarse,
development of reproductive organs, etc.
about secondary sex characters in boys such as the
growth of a beard, the voice becoming hoarse,
development of reproductive organs, etc.
Oestrogen: This hormone is
responsible for the development of secondary sexual characters in
females such as the enlargement of breasts,
development of female reproductive organs, etc.
responsible for the development of secondary sexual characters in
females such as the enlargement of breasts,
development of female reproductive organs, etc.
7)Choose the correct option.
(a) Adolescents should be careful about what they eat, because
(i) proper diet develops their brains.
(ii) proper diet is needed for the rapid growth taking place in
their body.
their body.
(iii) adolescents feel hungry all the time.
(iv) taste buds are well developed in teenagers.
ANSWER:- (ii) proper diet is needed for the rapid growth taking place in
their body.
their body.
(b) Reproductive age in women starts when their
(i) menstruation starts.
(ii) breasts start developing.
(iii) body weight increases.
(iv) height increases.
ANSWER:- (i) 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.
ANSWER: – (ii) chapati, dal, vegetables.
Q8. Write notes on—
(a) Adam’s apple.
(b) Secondary sexual characters.
(c) Sex determination in the unborn baby.
ANSWER:- a) Adam’s apple: The protruding part of the throat is
called Adam’s apple. It is the enlarged voice box or larynx which gets enlarged
and visible from outside in boys at the onset of puberty.
called Adam’s apple. It is the enlarged voice box or larynx which gets enlarged
and visible from outside in boys at the onset of puberty.
b) Secondary Sexual Characters are those characters which
distinguish a male from female
distinguish a male from female
c) Sex determination in unborn baby:
All human beings have
23 pairs of chromosomes in the nuclei of their cells. Two chromosomes out of
these are the sex chromosomes, named X and Y. A female has two X chromosomes,
while a male has one X and one Y chromosome. The gametes (egg and sperm) have
only one set of chromosomes. The unfertilised egg always has one X chromosome.
But sperms are of two kinds. One kind has an X chromosome, and the other
kind has a Y chromosome. When a sperm containing X
chromosome fertilises the egg, the zygote would have two X chromosomes and
develop into a female child. If the sperm contributes
a Y chromosome to the egg (ovum) at fertilisation, the zygote would develop
into a male child. This concludes that the sex
chromosomes of the father determine the sex of an unborn baby.