NCERT 8th Class (CBSE) Science: Reaching the Age of Adolescence

Question: What do you understand by ‘puberty’?

Answer: The stage of life when the body becomes capable of reproduction is known as puberty.

Question: Why is looking after physical health more important at adolescent age?

Answer: Walking, jogging, aerobics, outdoor games etc, are good for the growing adolescent body.

Question: Discuss the way heights in adolescents increases.

Answer: There is a sudden increase in height during adolescence, brought about by elongation of the bones of the arms and legs. During this age, different parts of the body do not grow at the same rate. For example: the arms and legs often grow faster than other parts, making them appear over-sized and awkward.

Question: What causes pimples to appear in adolescents?

Answer: There is increase in the activity of sweat and sebaceous (oil) glands. This leads to increased sweating often resulting in body odour. The skin becomes oilier. This often leads to appearance of acne and pimples on the face.

Question: What changes occur in the body shapes of boys and girls at adolescence?

Answer: In boys, the shoulder becomes broader and the chest becomes wider. The muscles grow more than in girls. In girls, the pelvic region widens, hips broaden, breasts develop and increases in size.

Question: Discuss the changes in the voices of boys and girls during the adolescence?

Answer: The voice box or the larynx begins to grow. It becomes bigger in boys than in girls. This is why boys develop a deep voice whereas girls have high pitched voice. In boys as the larynx begins to grow, the voice often cracks.

Question: Discuss menstrual cycle.

Answer: The cycle of producing and releasing a mature egg, the thickening of uterus wall and its shedding if fertilization does not occur is known as the menstrual cycle. This lasts for about two to eight days, every month. The menstrual cycle is controlled by hormones. At around 45-50 years of age, the menstrual cycle stops and the female is no longer reproductive. This is known as menopause.