responsible for changes taking place in the body?
is the time period between the beginning of puberty and adulthood. During this
period, the body undergoes several changes alongside reproductive maturity.
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.
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.
girls, the region below waist becomes wider.
prominent, the vocal cords become
longer and thicker. These changes cause the voice to become hoarse.
endocrine glands and hormones secreted by them.
testosterone is the male sex hormone produced by the
testis, and oestrogen is the female sex hormone
produced by the ovary.
they are known as sex hormones.
about secondary sex characters in boys such as the
growth of a beard, the voice becoming hoarse,
development of 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.
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.
distinguish a male from female
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.