Lesson: Reaching the Age of Adolescence

Exemplar:

Question: 1

The belief that the mother is completely responsible for the sex of the child is wrong because the child:

(a) Gets sex chromosome only from the mother.

(b) Develops in the body of the mother.

(d) Gets sex chromosome only from the father.

Solution

Question: 2

AIDS can spread from an infected person to another person through:

(a) Sharing food

(b) Blood transfusion

(d) A mosquito bite

Solution

Question: 3

Given below are events that lead to pregnancy and development of embryo:

(i) Fertilization of egg

(ii) Maturation of egg

(iii) Release of egg

(iv) Embedding of embryo in thickened uterine wall.

Which of the following options gives the correct order of sequence in which they occur?

(a) i, ii, iii, iv,

(b) ii, i, iii, iv

(d) ii, iii, i, iv.

Solution

Question: 4

For the metamorphosis of tadpoles which of the following elements must be available in water?

(a) Chlorine

(b) Carbon

(d) Iodine

Solution

Question: 5

The most conspicuous visible change that occurs in boys during puberty is:

(a) Oily face

(b) Sudden increase in height.

(d) Increased sweating.

Solution

Question: 6

Structures present in a cell which is responsible for determination of the sex of a baby is:

(a) Cytoplasm

(b) Cell membrane

(d) Chromosome

Solution

VERY SHORT ANSWER QUESTIONS (5)

Question: 7

Unscramble the underlined words in the following sentences.

(a) Reproductive life of a woman lasts from hacreemn to spauoemen.

(b) The development of a caterpillar to an adult butterfly is poommertaissh.

(d) Dannalier helps the body to adjust and fight the stress.

Solution

(a) Menarche, menopause

(b) Metamorphosis

(d) Adrenalin

Question: 8

Complete the following sentences:

(a) In females, the uterine wall thickens to receive the __________.

(b) Endocrine glands release hormones directly into ___________for transportation to the __________.

(d) Release of sex hormones is under the control of a hormone secreted from the _________.

Solution

(a) Fertilised egg

(b) Blood stream, target site

(d) Pituitary gland

Question: 9

Give a suitable word for each of the following statements.

(a) The site which responds to a hormone.

(b) Name of a gland which transports secretions through ducts.

(d) It marks the beginning of reproductive period.

Solution

(a) Target site

(b) Sweat glands/salivary glands/oil glands (any one)

(d) Puberty

Question: 10

Name the hormone that is released by testes at the onset of puberty.

Solution

Testosterone

Question: 11

Name the female hormone produced by ovaries that helps in development of mammary glands.

Solution

Estrogen

SHORT ANSWER QUESTIONS (7)

Question: 12

Match the hormones given in Column A with their deficiency disease given in Column B.

Column A Column B

(a) Thyroxine (a) Salt imbalance

(b) Growth hormone (b) Diabetes

(d) Adrenal hormone (d) Dwarfism

Solution

a-c

b-d

c-b

d-a

Question: 13

Shruthi always eats only dal and rice in every meal. She often falls ill and has become prone to diseases. Can you suggest changes in her diet which can make her healthy and free from disease?

Solution

Although dal and rice contain nutrients, but they lack all the required essential nutrients such as vitamins and minerals, so she should also include fruits, vegetables and green vegetables in her diet.

Question: 14

Mention any two features each that are seen in boys and girls each to distinguish them from each other at puberty.

Solution

Two features that are seen in boys at puberty are:

(i) Shoulder and chest become broader.

(ii) Voice becomes hoarse.

Two features that are seen in girls at puberty are:

(i) Waist becomes wider.

(ii) Development of breast

Question: 15

We should avoid taking medicines/drugs unless prescribed by a doctor.

Give reasons.

Solution

Although medicines cure certain diseases, there might be some side effects which might have a negative impact on human bodies. Some medicines should be taken in low dosages and some in higher doses, while some medicines can be allergic too for certain patients. All these details are known to the doctors alone. Hence, one should not take medicines without a doctor’s prescription.

Question: 16

A few of Paheli’s classmates eat potato chips and burgers regularly during the recess at school. Are they eating healthy? Give reasons.

Solution

No. Burgers and potato chips have little nutritional value that cannot fulfill all the essential nutrition required by the human body.

Question: 17

Read the statements given below and fill up the blanks with the correct words listed in the box.

high-pitched, ductless, nutrients, thyroxine

(a) The meal that includes all __________ is a balanced diet.

(b) Insufficient production of __________ in the tadpoles leads to their incomplete development.

(d) After attaining puberty boys develop a__________ voice.

Solution

(a) Nutrients

(b) Thyroxine

(d) High-pitched

Question: 18

Fill the blank circles in the given figure and identify the sex of child A and B.

Solution

LONG ANSWER QUESTIONS (10)

Question: 19

During adolescence, the bodies of boys and girls undergo certain changes.

Given below are a few of those changes:

(a) Broad shoulders

(b) Wider chests

(d) Development of muscles

(e) Development of mammary glands

(f) Growth of facial hair

(g) Acne and pimples on face

(h) Development of sex organs

(i) High-pitched voice

(j) Growth of pubic hair.

Categorize these changes into those that occur in boys and those that occur in girls and fill in the table given below.

Solution

Body Changes in boys	Body Changes in girls
Broader shoulders	Development of mammary glands
Growth of muscles	Wider region below waist
Wider chests	High-pitched voice
Growth of facial hair	Development of sex organs
Development of sex organs	Acne and pimples on face
Acne and pimples on face	Development of pubic hair
Development of pubic hair

Question: 20

In the figure given below, mark the positions of the endocrine glands which release the hormones that:

(a) Controls the release of sex hormones.

(b) Is responsible for the secondary sexual characters in boys.

(d) Maintains the correct salt balance in the blood.

Solution

(a) Pituitary gland that control the release of sex hormones.

(b) Testis releases testosterone which is responsible for the secondary sexual characters in boys.

(d) Adrenal gland maintains the correct salt balance in the blood.

Question: 21

Given below are certain food items required for proper nourishment of adolescents. Name the nutrients present in the food items and write their functions.

S. No.	Food items	Major Nutrient	Functions
1.	Pulses and nuts
2.	Oranges and Amla
3.	Sugar, Roti
4.	Oils
5.	Vegetables

Solution

S. No.	Food items	Major Nutrient
1	Pulses and nuts	Proteins	Growth, repair of body cells
2	Orange and Amla	Iron and Vitamins	Formation of blood, keeps the body healthy
3	Sugar, Roti	Carbohydrates	Provide energy
4	Oils	Fats	Provide energy
5	Vegetables	Vitamins and Minerals	Keeps the body healthy and disease free

Question: 22

Name the hormone which would be released during the following situations:

(a) A frightened person.

(b) Growth of a child to adult.

(d) Development of tadpole to frog.

Solution

(a) Adrenaline

(b) Growth hormone

(d) Thyroxine

Question: 23

In human females, each time during maturation and release of egg the inner wall of uterus thickens. Is this thickening permanent? Give reasons.

Solution

No, thickening of the uterus wall is not permanent. If the egg is fertilized by a sperm, it is developed and embedded in the uterus wall, which results in pregnancy. The thickened uterus lining is discharged only at the time of child birth. If the egg is not fertilized, the egg along with the uterus lining is shed off during menstruation.

Question: 24

John and Radha were classmates since childhood. When Radha became eleven years old, she developed a little swelling on her neck.

She visited the doctor who started medication for her.

After a few years, John also developed a slight protrusion on his throat.

He got worried and went to the doctor. But the doctor assured him that it was a normal feature in boys while they are growing up.

Can you think of any reasons for the difference in diagnoses?

Solution

Protrusion on the throat is common among adolescent boys, hence John need not worry about it. On the other hand, in the case of Radha, it is uncommon to have a protrusion in the neck due to adolescence among girls. It might be due to a disease called goitre, a condition caused by the thyroid gland, producing insufficient quantity of thyroxine.

Question: 25

Observe the chart and graph given in the figure below carefully and answer the following questions.

(a) Which of the line represents the height of boys?

(b) Which line represents the height of girls?

(d) Is this pattern true for each individual?

Solution

(a) The bottom line shows the height of the boys as shown in the figure below.

(b) The top line shows the height of the girls as shown in the figure below.

(d) No, height growth varies among individuals. At puberty, some individuals may grow gradually and some may suddenly grow in height and later slow down.

Question: 26

Salma had a very soft and smooth skin during her childhood. As she entered adolescence, she developed pimples on her face.

The skin specialist advised her to wash her face at regular intervals. Can you explain the reasons for the appearance of pimples on her face and suggest ways to prevent them?

Solution

After entering adolescence, the secretion of sweat glands and sebaceous glands increase, and that leads to the development of acne and pimples. Using face wash regularly and washing face at regular interval may help to reduce the pimples.

Question: 27

Our government has legalised the age for marriage in boys and girls. Give reasons as to why one should get married after a certain age.

Solution

In our country, the legal age for marriage is 18 years for girls and 21 years for boys. This is because, girls are not physically ready to bear a child until they are 18 years of age and pregnancy below 18 years of age might cause serious health problems for both mother and child. Additionally, both boys and girls are not mentally ready at a very early age for marriage and associated responsibilities. Hence, the government has legalized the age for marriage for boys and girls.

Question: 28

It is believed that height of a child depends upon the genes inherited from parents. However, it is often seen that tall parents may have short children and vice-versa. Are there factors other than genes that can cause these variations?

Solution

Children inherit genes from their parents that carry genetic information and have characteristics similar to their father and mother. However, there may be other factors that might affect the height of a child. These factors include insufficient growth hormones due to deficiency of vitamins and minerals, increased or decreased secretion of thyroxin by thyroid glands, etc.