|Question 1. What is the term used for secretions of endocrine glands responsible for changes taking place in the body? |
|Answer :The secretions of endocrine glands responsible for changes taking place in the body is called hormones.Hormones are chemical substances, which are released by endocrine glands directly into the blood stream.. The changes which occur at onset of puberty and adolescence are controlled by hormones |
|Question 2. Define adolescence. |
|Answer :The period of life, when the body undergoes changes, leading to reproductive maturity, is called adolescence.Adolescence begins around the age of 11 and lasts upto 18 or 19 years of age.Since this period covers the ‘teens’ , adolescents are also called ‘teenagers’. In girls, adolescence may begin a year or two earlier than in boys. Also, the period of adolescence varies from person to person.The Adolescence is marked by the onset of puberty in which growth of the reproductive organs , change in body size, change in body height, change in Voice etc takes place. |
|Question 3. What is menstruation? Explain. |
|Answer :In females, the reproductive phase starts at onset of puberty around 10 to 12 years of age and continues till 40-45 yrears of age. During this period, One ovum matures and is released by one of the ovaries once in about 28 to 30 days. During this period, the wall of the uterus becomes thick and prepares itself to receive the developing fertilised egg. In case there is no fertilisation, the released egg, and the thickened wall lining of the uterus along with its blood vessels, breaks down and goes out of the body. This periodic bleeding due to reproductive cycle in women which is called menstruation. |
|Question 4. List changes in the body that take place at puberty. |
|Answer :List changes in the body that take place at puberty. |
- Increase in Height - The most visible change during puberty is the sudden increase in body height.
- Change in Body Shape - The onset of puperty is marked by characteristic changes in body shape.In boys, the shoulders of boys generally broaden . In girls,the region below the waist becomes wider. In boys, the muscles of the body grow more prominently than in the girls.Thus, changes occurring in adolescent boys and girls are different.
- Voice Change - At puberty, the voice box or the larynx begins to grow.Boys develop larger voice boxes than girls, resulting in Generally, girls have a high pitched voice, whereas boys have a deep voice..
- Increased Activity of Sweat and Sebaceous Glands-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.
- Development of Sex Organs- At puberty, male sex organs like the testes and penis develop completely. The testes also begin to produce sperms. In girls, the ovaries enlarge and eggs begin to mature. Also ovaries start releasing mature eggs.During this period change in Secondary Sexual Characters results in development of breasts in girls and apperance of facial hair (moustache and beard) boys.
- Reaching Mental, Intellectual and Emotional Maturity -The puberty is marked by Adolescence stage, in which a person becomes more thoughtful, concious and independent than before
|Question 5. Prepare a Table having two columns depicting names of endocrine glands and hormones secreted by them. |
|Answer : |
|Names of Endocrine Glands ||Type of hormones secretions |
|Pituitary gland ||Growth Hormone & Hormone Stimutors |
|Pancreas ||Insulin |
|Thyroid ||Thyroxine |
|Adrenals ||Adrenalin |
|Testes ||Testosterone |
|ovaries ||Estrogen, |
| || |
|Question 6. What are sex hormones? Why are they named so? State their function. |
|Answer :-The sex hormones are also known as male hormone (testosterone) and female hormone (estrogen). These are sereted by testes and ovaries in male and female respectively. These hormones are responsible for the male and female secondary sexual characters. Further, the sex hormones, under the control of hormones from the pituitary gland,secrete many hormones, one of which makes ova mature in the ovaries and sperms form in the testes |
|Question 7. Choose the correct option. |
- Adolescents should be careful about what they eat, because
- proper diet develops their brains.
- proper diet is needed for the rapid growth taking place in their body.
- adolescents feel hungry all the time.
- taste buds are well developed in teenagers.
- Reproductive age in women starts when their
- menstruation starts.
- breasts start developing.
- body weight increases.
- height increases.
- The right meal for adolescents consists of
- chips, noodles, coke
- chapati, dal, vegetables.
- rice, noodles and burger.
- vegetable cutlets, chips and lemon drink.
|Answer : |
- Adolescents should be careful about what they eat, because - (ii) Proper diet is needed for the rapid growth taking place in their body.
- Reproductive age in women starts when their - (i) menstruation starts
- The right meal for adolescents consists of -(ii) chapati, dal, vegetables.
|Question Write notes on— |
- Adam’s apple.
- Secondary sexual characters.
- Sex determination in the unborn baby.