NOTES PREPARED BY
ASHAQ HUSSAIN BHAT
TEACHER SCHOOL
EDUCATION DEPARTMENT
JAMMU AND KASHMIR
CHAPTER 10
Reaching the Age of Adolescence
KEYWORDS
Adolescence: The period of life, when the body undergoes changes, leading to reproductive maturity.
Puberty: the age at which boys and girls become capable of reproduction
Adam's apple: Protruding part of the throat.
Larynx: Voice box.
Secondary sexual characters: Features, which help to distinguish the male from the female.
Hormone : Chemical substances, which controls the changes occuring at adolescence.
Target site: Hormones reach these parts by bloodstream.
FSH: Follicle Stimulating Hormone, makes ova mature in the ovaries and sperms form in the testes.
Menopause : Stoppage of menstruation at age of 45 to 50 years.
Chromosomes: Thread-like structures in the fertilized egg, contains the instruction for determining the sex of the unborn.
Goitre: A disease of the thyroid gland.
TEXT BOOK EXERCISE
Q.1. What is the term used for secretions of endocrine glands responsible for changes taking place in the body?
Ans. Hormones are the secretions of endocrine glands responsible for changes taking place in the body.
Q.2. Define adolescence.
Ans. Adolescence is defined as the period of life (11 to 18 or 19 years of age) when the body undergoes changes leading to reproductive maturity.
Q.3. What is menstruation ? Explain.
Ans. When the egg produced by ovary does not get fertilised, the released egg and the thickened lining of the uterus along with its blood vessels are shed off. This causes bleeding in women which is called menstruation.
Q.4. List the changes in the body that take place at puberty.
Ans. The following changes take place in the body at puberty.
(i) Sudden increase in height. The bones of the arms and legs elongate and make a person tall.
(ii) Change in the body shape. In boys, the shoulders become broader and the chests become wider. In girls, the region below the waist becomes wider.
(iii) Voice change. In boys, the voice becomes deep or hoarse, Generally the girls have high pitched voice.
(iv) Increased activity of sweat and sebaceous (oil) glands. Pimples may develop on the face.
(v) Development of sex organs. In boys, testes begin to produce sperms. In girls, ovaries enlarge and start releasing matured eggs.
(vi) Reaching mental, intellectual and emotional maturity.
These changes are natural part of growing up.
Q.5. Construct a table having two columns depicting names of endocrine organs and hormones secreted by them.
Ans.
S. No Name of Endrocine Gland Secreted Hormone
1.Testes. Testosterone
2.Ovaries. Estrogen
3.Thyroid. Thyroxine
4.Pancreas. Insulin
5.Adrenals. Adrenaline
6.Pituitary. FSH
Q.6. What are sex hormones? Why are they named so ? State their function.
Ans. The hormones which help and control the formation of secondary sexual characters are called sex hormones. They are called sex hormones because they control the sexual activities and help us to distinguish boys from gir
The sex hormones help to develop, the secondary sexual characters, like in boys they control formation of sperms by testes and growth of facial hair. In girls they help to develop breast, milk secreting glands or mammary glands.
Q.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.
(iii) adolescents feel hungry all the time.
(iv) taste buds are well developed in teenagers.
(b) Reproductive age in women starts when their :
(i) menstruation starts.
(ii) breasts start developing.
(iii) body weight increases.
(iv) height increases.
(c) Which of the following constitutes the right meal for adolescents?
(i)Chips, noodles, coke.
(ii) Chapati, dal, vegetables,
(ii) Rice, noodles and burger.
(iv) Vegetable cutlets, chips and lemon drink.
Ans. (a)-(ii); (b) - (i); (c) - (ii).
Q.8. Write notes on:
(i) Adam's apple,
(ii) Secondary sexual characters,
(iii) Sex determination in the unborn baby.
Ans. (a) Adam's apple: At puberty, the voice box or the larynx begins to grow. Boys develop larger voice boxes. The growing voice box in boys can be seen as a protruding part of the throat called Adam's apple
(b) Secondary sexual characters :In girls, breasts begin to develop at puberty and boys begin to grow facial hair, that is, moustaches and beard. As these features help to distinguish the male from the female they are called secondary sexual characters. Boys also develop hair on their chest.
(C)Sex determination in the unborn baby: Sex chromosomes determine sex in human beings. 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.
Q9. 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. Teenage
5. Hormone reaches here through blood stream
6. Voice box
7. Changes at adolescence constitute
Ans:-
1.Testostorine
2.Thyroid
3.Adolescent
4. Endocrine
5. Target site
6.Larynx
7.Puberty
8. Hormone
9.Insulin
10.Estrogen
ADDITIONAL SHORT ANSWER TYPE
Q.1. What are hormones?
Ans. Hormones are chemical substances, which are secreted from endocrine glands or endocrine system. They control the changes which occur in adolescence.
Q.2. What is the role of hormones in initiating reproductive function?
Ans. Endocrine glands release hormones into the blood-stream to reach a particular body part called target site. This may be an organ, tissue or cell. The target site responds to the hormones. There are many endocrine glands in the body. The testes and ovaries secrete sex hormones. These hormones are responsible for the male and female secondary sexual characters. Further, the sex hormones are under the control of hormones from pituitary gland. Pituitary secretes many hormones, one of which makes ova mature in the ovaries and sperms form in the testes.
Q.3. How is menstrual cycle controlled ?
Ans. Menstrual cycle is controlled by hormones. The cycle includes the maturation of the egg, its release, thickening of uterine wall and its breakdown if pregnancy does not occur. In case the egg is fertilized. It begins to divide and then gets embedded in the uterus, for further development.
Q.4. When do thyroid and adrenals secrete their hormones ?
Ans. Thyroid and adrenals secrete their hormones when they receive orders from the pituitary through its hormones.
Q.5. Do all parts of the body grow at the same rate during adolescence ?
Ans. No, all parts of the body do not grow at same rate. Sometimes the arms and legs or hands and feet of adolescents look oversized and out of proportion with the body, but soon other parts catch up and result in proportionate body.
Q.6. Why are endocrine glands called ductless glands ?
Ans. Unlike some glands, such as, sweat glands, oil glands and salivary glands release their secretions through ducts, but endocrine glands release hormones directly into the bloodstream. So, they are also called as ductless glands.
Q.7. Which hormone in male and female is released which initiates changes at puberty ?
Ans. In males, testosterone is released by the testes at the onset of puberty, which cause change in boys. In girls, estrogen is produced by ovaries, which makes the breasts develop.
Q.8. What is the role of pituitary gland ?
Ans. The pituitary gland is situated near the brain, is also called master gland because it influences the functioning of other glands. The sex hormones are under the control of hormones released from pituitary gland. Hormones from pituitary stimulate testes and ovaries to release testosterone in males and estrogen in females. Also, thyroid and adrenals secrete their hormones when they receive orders from the pituitary through its hormones. Pituitary also secretes growth hormone, which is necessary for normal growth of a person.
Q.9. What is Menarche ?
Ans. The first menstrual flow in females which, starts at puberty is turned as menarche.
Q.10. What is Menopause ?
Ans. In females, the menstrual cycle stops at 45 to 50 years of age. This stoppage of menstruation is termed as menopause.
Q.11. What is the function of thyroxin in frog?
Ans. In frog, metamorphosis is controlled by thyroxin hormone which is released by thyroid. lodine present in water is needed for the production of thyroxin. In sufficient production of thyroxin due to lack of iodine stops the growth of a tadpole to become an adult
Q.12. Why it's important to maintain personal hygienic ?
Ans. Everyone should take bath at least once a day. All parts of the body should be washed and cleaned every day. In teenagers, due to increased activity of sweat glands the body becomes smelly which can cause bacterial infection.
Q.13. Why young people get acne and pimples on the face at the time of puberty.
Ans. During puberty the secretion of sweat glands and sebaceous glands (oil glands) increases. Many young people get acne and pimples on the face at this time because of the increased activity of these glands in the skin.
Q.14. What is the importance of Adrenal gland?
Ans. Adrenal secrets hormones which maintain the correct salt balance in the blood. Adrenals also produce the hormone adrenalin termed "stress hormones' because it helps to calm down when one is very angry or embarrassed or worried.
Q.15.How do sex hormones work in human body?
Ans. In males, the testosterone is secreted by testes and it causes growth of moustaches and beard. In girls' estrogen causes the development of mammary glands. They develop inside the breast and cause enlargement of breasts.
Q.16 What are the nutritional needs of the adolescents ?
Ans. Adolescents marks rapid growth in body. So, body needs a lot of energy to perform growth functions. It becomes necessary for body to have proper nutrition. Balance diet with lots of fruits can fulfill the nutritional requirements of the adolescents.
Q.17.Name the virus causes AIDS. What are medium through which this virus is transmitted?
Ans. AIDS is caused by a virus named HIV. It can be transmitted from an infected person to a healthy person by following ways:
(1) By infected syringes.
(1) By infected mother to an infant.
(ii) By sexual contact with infected person.
LONG ANSWER TYPE QUESTIONS
Q.18. What are myths and taboos regarding bodily changes in case of adolescents ?
Ans. There are many myths and taboos regarding, bodily, changes that adolescents experience. Some of these are given below:
(i) A girl becomes pregnant, if she looks at boys during menstruation.
(ii) A drop of semen lost means loss of 10 drops of blood, which will make the boy weak.
(i) The mother is responsible for the sex of the child.
(iv) A girl should not be allowed to work in the kitchen during menstruation.
These should be discarded out rightly.
Q.19. What are the drawbacks of early marriage and motherhood?
Ans. The followings are the drawbacks of early marriage and motherhood :
(i) The legal age for marriage is 18 years for girls and 21 years for boys. This is because teenage girls are not prepared mentally or physically for motherhood.
(ii) Early marriage and motherhood cause health problems in the mother and the child.
(iii) It also curtails employment opportunities for a young woman and causes mental agony as she is not ready for the responsibilities of mother hoods.
Q.20. What do you understand by sex chromosomes ? Discuss in brief.
Or
Explain the sex determination of baby in human.
Ans. Inside the fertilized egg or zygote is the instruction for determining the sex of the unborn. This instruction is present in the thread-like structures in the fertilized egg, called chromosomes. The chromosomes are present inside the nucleus of every cell. 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 unfertilised egg always has one X chromosome. But testes produce two kinds of sperms. One kind has an X chromosome, and the other kind has a Y chromosome. When a sperm containing X chromosome fertilises the eggs the zygotes develops into female child. If sperm contributes a Y chromosome to the egg at fertilisation, the zygote develops into male child.
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