NCERT Class 8 Science — Chapter 4: Reaching the age of adolescence

With reference to the role of hormones in the life history of insects and frogs, consider the following statements: 1. The change from larva to adult is called metamorphosis. 2. In frogs, metamorphosis is controlled by the hormone insulin. 3. Thyroxine production requires the presence of iodine in the water. Which of the statements given above is/are correct?

Consider the following statements regarding the nutritional needs of adolescents: 1. A balanced diet consists exclusively of proteins and vitamins. 2. Iron is essential for adolescents because it builds blood. 3. Chips and packed snacks have high energy but limited nutritional value compared to regular meals. Which of the statements given above is/are correct?

With reference to HIV/AIDS, consider the following statements: 1. It is caused by a virus. 2. It can be transmitted from an infected mother to an infant through milk. 3. It can be transmitted by sharing syringes used for injecting drugs. 4. It can be transmitted through sexual contact with an infected person. Which of the statements given above are correct?

Consider the following statements regarding the Pituitary gland: 1. It is located at the base of the brain. 2. It secretes insulin necessary for sugar metabolism. 3. It functions independently and does not influence other endocrine glands. Which of the statements given above is/are correct?

With reference to the onset of menstruation, consider the following statements: 1. The first menstrual flow which begins at puberty is termed menarche. 2. Menstruation occurs once in about 10 to 15 days. 3. At 45 to 50 years of age, the menstrual cycle stops, which is termed menopause. Which of the statements given above are correct?