CBSE Class 8 Science Chapter 7 Reaching The Age Of Adolescence Short Answer Questions
Question 1. Define adolescence as stated by the WHO. Why is adolescence also called teenage?
Answer: The World Health Organisation (WHO) defines adolescence as the period of life between 11 and 19 years of age. Since adolescence covers the teen period, i.e., 13-19 years of age, adolescence is also called ‘teenage’.
Question 2. Salma had 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? Competency-Based Question
Answer: During adolescence, the secretion of sweat glands and sebaceous glands increases, leading to acne and pimples. Regular face wash keeps the face clean and dry and helps to reduce pimples.
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Question 3. Mention any two features that are seen in boys and girls, each to distinguish them from each other at puberty.
Answer: Two features seen in boys at puberty are
- Growth of facial hair.
- Voice becomes hoarse.
- Two features seen in girls at puberty are
- Development of breasts.
- The region below the waist becomes wider
Question 4. In human females, each time during maturation and release of an egg, the Inner wall of the uterus thickens. Is this thickening permanent? Give reasons.
Answer: No, this thickening of the uterine wall is not permanent. If the egg gets fertilised, it starts developing and gets embedded in the uterine wall, resulting in pregnancy. During pregnancy, no more eggs are released, and the thickened lining is discharged only when the baby Is born. However, if fertilisation does not occur, the released egg and the thickened lining are shed off, resulting in menstruation.
Question 5. Fill the blank circles in the figure and identify the sex of child A and B
Answer:
Question 6. Name the hormone that would be released during the following situations.
- A frightened person
- Growth of a child into an adult
- Development of the caterpillar into the moth
- Development of tadpole to frog
Answer: Adrenaline is secreted from the adrenal gland during stress conditions like fright or fear, anger, worry or embarrassment.
- Growth hormone is secreted from the pituitary gland to regulate the normal growth ofa person, i.e., growth of a child to adult.
- Insect hormones control the development of the caterpillar and the lo moth.
- Thyroxine is produced by the thyroid gland to control the development of a tadpole into a frog.
Question 7. A tadpole is kept in a lagoon with deficient water. How will it affect its growth? Explain
Answer: Tadpoles growing in Iodine deficient water have retarded growth. This is because the growth and development is regulated by thyroxine hormone which is produced by thyroid gland As loodine required for thyroxine production, retarded growth Is seen In tadpoles When kept In Water.
Question 8. Liia always eats only dal and rice in everyday meals; she often falls and has become prone to diseases. Can you suggest changes in her diet Which can make her healthy and free from diseases?
Answer: Lila’s diet is not balanced because her meals do not contain (lie adequate nutrition. She likes only proteins mid airliohydriilcn In every mail. She requires vitamins mid minerals in her meal to protect her from various diseases, Thus, I would suggest her lo include fruits and vegetables in her meal as a source of vitamins and minerals.