Q1. What is adolescence?
Ans. It is the period of life when
the body undergoes changes, leading to reproductive maturity.
Q2. Define puberty.
Ans. The stage when human body
becomes sexually mature.
Q3. What is adam’s apple?
Q3. What is adam’s apple?
Ans. The growing voice box in boys can be seen as a protruding part of the throat called adam’s apple.
Q4. What are secondary sexual characters?
Ans.These are the features that help to distinguish males from females.
Q5. Define the following terms.
Ans. (a) Hormone- they are chemical messengers for various processes and activities in the body
(b) Endocrine glands- the ductless glands which secrete hormones directly into blood.
Q6. Enlist the changes occurring in
males and females during puberty.
Ans.
Type
of change
|
In
girls
|
In
boys
|
Increase
in height
|
Sudden
increase
|
Sudden
in crease
|
Body
shape
|
Waist
widens
|
Shoulders
broadens
|
Voice
change
|
High
pitched
|
Voice
becomes deeper
|
Development
of sex organs
|
Ovaries
mature and releases eggs.
|
Testes
matures and produces sperms
|
Q7. What is the role of hormones in
initiating reproductive function?
Ans.1. Hormones from
pituitary stimulate testes and ovaries to release testosterone and estrogen respectively.
3. These sex hormones reach to
target sites via blood.
4. Then stimulate changes in the
body at the onset of puberty.
Q8. Discuss reproductive phase
of life in women.
Ans. In females the reproductive
phase of life begins at puberty and continues till they reach the age of 45-50 years. The egg begins to
mature with the onset of puberty. One mature ovum is released by one of
the ovaries every month. The process is called ovulation. During this period,
the walls of the uterus become thick so as to receive fertilized
egg. Then this egg gets implanted in the uterus resulting in pregnancy.
Q9 Give reasons for the following :
a. Tadpoles growing in iodine
deficient water have retarded growth.
Ans. The process of growth and
development is regulated by thyroxine hormone which is produced by thyroid
gland. Iodine is required for thyroxine production. That is why retarded growth
is seen in tadpoles living in iodine deficient water.
b. Voice becomes hoarse in
adolescent boys.
Ans. Sometimes the muscles of the
growing voice box go out of control and the voice becomes hoarse.
c. Adolescents experience acne and
pimples.
Ans. This is dues to increased
activity of sebaceous (oil) glands in the skin.
d. Females have no role in
determining gender of a child.
Ans. Y- chromosomes that leads to a
boy offspring is contributed by male parent. That is thesperms are of two types,
having either X or Y chromosome.
10. What are the causes of AIDS?
Ans. The causes of AIDS are:
1. Sharing needle of the
syringe
2. unprotected sex with infected
person.
3. blood transfusion from infected
person to healthy one.
4. infected mother can pass HIV through milk to
an infant.
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8th Chapter: Reaching the Age of Adolescence
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Science Mission class8 Chp10 Reaching the Age of Adolescence | Download solution |
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CBSE Solved Questions Paper-1
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CBSE Solved Questions Paper-2
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CBSE Solved Questions Paper- 3
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CBSE Solved Questions Paper- 4
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VIII
Reproduction in Animals
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Reproduction in
Animals [E-NOTES]
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CBSE Test Paper
[solved question]
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CBSE Worksheet for
practice
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Reproduction &
Endocrine [solved]
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Chapter 10- Reaching the age of Adolescence
ReplyDeleteAnswer the following questions
1. Name the hormone produced when one is very angry or worried.
2. The chemicals secreted by endocrine gland are called _________.
3. How many pairs of chromosomes are found in the nuclei of their cell?
4. Why endocrine glands are termed ductless glands?
5. Name the disease caused due to lack of insulin producation.
6. Name the hormone that controls metamorphosis in a frog. Name the mineral required by this hormone.
7. Name the gland which controls the activity of other endocrine glands.
8. Name the hormone which maintains the correct salt balance in the blood.
9. Name three glands which release their secretions through ducks.
10. Name the hormone produced by thyroid gland and the disease caused due to lack of its producation.
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