The document discusses adolescence, a developmental stage from approximately 10 to 19 years during which physical and reproductive changes occur, including puberty and menstruation. It outlines menstruation cycles, hormonal influences, health recommendations, and the process of sex determination in humans. Additionally, it highlights the roles of endocrine glands and hormones in biological processes, and includes a section for revision questions on these topics.

1. Reaching The Age of
Adolescence
BY REHET KAUR BHATIA 8D

2. Adolescence
Adolescence is the period
of life when changes take
place in the body which
leads to reproductive
maturity.
 Adolescence begins at
about 10 years and lasts till
18 or 19 years.

3. Puberty
The Process of Bodily changes
that take place during
adolescence
Puberty Marks the start of
adolescence
& The end of it marks
Reproductive Maturity.

4. Changes During Puberty
I. Height Increases
II. Voice Changes
III. Body shape Changes
IV. Acne develop
V. One Develops Mentally,
emotionally , Intellectually .
VI. Sex Organs Develop.

5. Menstruation
• Every Month ovary of a girl releases egg cells {ova}.
• After that a cushiony layer {endometrium} get’s
formed in the uterus.
• If fertilization doesn’t occur then the Ova comes out
of the vagina in form of blood along with
endometrium.
• This results in Bleeding phrase in female for 4-5
days.
• This cycle is Menstruation cycle.
• Menarche-First Menstrual bleeding in a girl’s life
• Menopause-The end of Menstruation it happens at
45-50 yrs. of age.

6. Sex Determination
• A Human body has 48 Chromosomes out of
these pairs 22 are identical but 23rd pair can be
identical or different.
• In 23rd pair female chromosome has xx and
male one has xy.
• a sperm may have X or Y chromosome as 23rd
chromosome. an ovum has X chromosome as
23rd chromosome.
• If a sperm with X chromosome fertilizes the
egg, the zygote thus formed will lead to birth
of a girl child.
• If a sperm with Y chromosome fertilizes the
egg, the zygote thus formed will lead to birth
of a male child.

7. Health is Wealth
•Balanced Diet
•Personal Hygiene
•Say ‘NO’ to Drugs
•Having Proper Amount
Of Sleep.

8. Endocrine Glands
Endocrine glands are
ductless glands of
the endocrine
system that secrete
their products,
hormones, directly
into the blood.
Endocrine Gland Hormone Function
Pituitary Growth hormone
Normal growth of
body
Thyroid Thyroxin Normal metabolism
Pancreas Insulin
Glucose
metabolism
Adrenal Adrenalin
Prepares the body
for a fight or flight
like situation.

9. Role of Hormone in Completing the Life Cycle of
insects and frogs
• Insect hormones control the
metamorphosis of larva into
adult.
• Thyroxin controls the
metamorphosis of tadpole into
frog.
• If a frog lays eggs in iodine
deficient water, the tadpoles
will not develop into frogs and
will die.

10. Let’s Revise
Q1Give a suitable word for each of the following
statements.
(a) The site which response to a hormone.
(b) Name of a gland which transports secretions
through ducts.
(c) Chemicals which control changes at the
adolescence stage.
(d) It marks the beginning of the reproductive
period.
Q2 A few of Pamela's classmates eat potato chips
and burgers regularly during the recess at school.
Are they healthy eating habits? Give reasons.
Q3 What is menstruation? Explain

11. Answers For reference
Answer 1
1. Target site
2. Sweat glands or oil glands (anyone)
3. Hormones
4. Puberty
Answer 2
No, Potato chips and burgers are not healthy as it contains very little
nutritional value in it and is not the good foods to eat it regularly.
Answer 3
In females, one egg is released by either of the ovaries during each
month. After that, the uterus develops a thickening to support a foetus
to prepare for a possible pregnancy. If fertilization does not take place;
egg and thickening in uterus are discarded in small fragments. This
results in bleeding through the vagina for some days. The bleeding
(through vagina) at the end of menstrual cycle is called menstruation.