CBSE Class 8 Science Chapter 7 Reaching The Age Of Adolescence LAQs

Real-Life Examples To Explain Adolescence Changes: Class 8 Long Answer Type Questions

Question 1. During adolescence, the body of boys and girls undergoes critical changes. Given below of those changes

1. Broad shoulders
2. Wider chosts
3. Wider region below the waist
4. Development of muscles
5. Development of mammary glands
6. Growth of facial hair
7. Acne and pimples on the face
8. Development of sex organs
9. High-pitched voice
10. Growth of pubic hair

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

Body changes during adolescence

Answer: Body changes during adolescence are given below

Question 2. In the figure, mark the position of the endocrine glands that release the hormones that control the release of sex hormones.
Answer: Pituitary gland. It releases hormones that control the release of sex hormones, i.e., testosterone in males and oestrogen in females.

Answer:

Testis. It releases testosterone, which is responsible for the secondary sexual characteristics in boys prevents diabetes.

The Pancreas releases insulin, which prevents diabetes

Maintain the correct salt balance in the blood.

The adrenal gland releases aldosterone, which maintains the correct salt balance in the blood.

Read And Learn More CBSE Class 8 Science Long Answer Questions

Question 3. Choose the correct option.

1. Adolescents should be careful about what they eat, because

1. A proper diet develops their brains
2. A proper diet is needed for the rapid growth taking place in their body
3. Adolescents feel hungry all the time
4. Taste buds are well developed in teenagers

2. Reproductive age in women starts when their

1. Menstruation starts
2. Breasts start developing
3. Body weight Increases
4. Height increases

The right meal for adolescents consists of

1. Chips, noodles, cake
2. Chapati, dal, vegetables
3. Rice, noodles, and a burger
4. Vegetable cutlets, chips and lemon drink

Answer: Adolescents should be careful about what they eat because a proper diet is needed for the rapid growth taking place in their bodies.

1. Reproductive age in women starts when their menstruation starts.
2. The right meal for adolescents consists of chapati, dal and vegetables
3. Question 8 Write notes on
4. Adam’s apple.
5. Secondary sexual characteristics.
6. Sex determination of the unborn baby.

Answer:

Adam’s apple: In males, the protruding part of the growing voice box is called Adam’s apple. In boys, the voice box (larynx) develops larger than in girls, and this protruding part is seen as a bulge in the neck area.

Secondary sexual characteristics: The physical features that help to distinguish males from females are called secondary sexual characteristics. These characters develop at the time of puberty. The secondary sexual characteristics in humans are given below. In males,

1. Growth of pubic hair, beard, and moustaches.
2. Hair on chest and underarms.

In females,

1. Enlargement of breasts.
2. Appearance of pubic hair, hair underarms.

Sex determination of the unborn baby. The Sex of the unborn baby is determined by the sex chromosomes, i.e., X and Y.

In females, the gamete (i.e., egg) has only one X chromosome, but in males, the gamete (i.e. sperm) may have an X chromosome or Y chromosome.

If the egg fertilises with sperm containing an X chromosome, the zygote will develop into a female (XX), and if the egg fertilises with sperm containing a Y chromosome, the zygote will develop into a male (XY)

Question 4. The table given below shows the trend in likely heights of boys and gills os they grow in age. Draw graphs showing height and Ago for both boys and girls on the same graph paper. What conclusions can be drawn from this graph?

Answer: We conclude that initially. Girls grow faster than boys, hitting about 18 years of age. Both reach their maximum height. The rate of growth in brightness varies in Different individuals.

Question 4. The heights of students of four different sections of grade 8 are measured. The table shows the percentage of maximum height up to which the students in each section have grown

In which class have both the boys and the girls reached the end of puberty?

1. Section A
2. Section B
3. Section C
4. Section D

Answer: Section B.

What can be concluded from the table?

1. Girls are taller than boys in all four classes
2. Girls attain their maximum height earlier than boys
3. Girls grow faster than boys throughout their childhood
4. Girls and boys attain their maximum height at the same age

Answer: Girls attain their maximum height earlier than boys.

Question 5. An ovum contains one X chromosome. A sperm contains an X or a Y chromosome. A sperm can fertilise an ovum to produce two different zygotes.

1. Which chromosome does the female zygote receive from the mother and the father?

Answer: 1. Mother X-chromosome, father X-chromosome

Which of those stntomonts is supported by the picture?

Circle ‘Yes’ or ‘No’ for the correct response

Answer: A. Yes B. Yes C. No

Question 6. Diabetes is a condition in which the blood sugar level of a person rises above the normal level. The table below shows the average range of blood sugar levels at fasting

Doctors prescribe insulin injections for patients with high blood sugar levels. However, glucagon is injected in an emergency if the blood sugar level of a person drops too low.

Which of these is true about the gland that secretes insulin in the human body?

1. It has no ducts
2. It is located on the skin
3. It controls the function of all other glands
4. It releases hormones that help in growth

Answer: It has no ducts

Under what conditions of blood sugar level is glucagon likely to be injected?

1. Below 60 mg/dL
2. 80-100 mg/dL
3. 100-120 mg/dL
4. Above 120 mg/dL

Answer: Below 60 mg/dL