NCERT Class 11 Science — Chapter 9: Chemical Coordination and Integration

Which of the following are associated with deficiency of thyroid hormones? 1. Cretinism occurs when deficiency happens in old age. 2. Goitre formation due to iodine deficiency. 3. It ensures perfectly regular menstrual cycles. Select the correct answer using the code below:

Regarding exophthalmic goitre (Graves' disease), which of the following is/are correct? 1. It is a form of hyperthyroidism. 2. It involves sinking of the eyeballs. 3. It is characterised by an increased basal metabolic rate. Select the correct answer using the code below:

Assertion (A): Thyrocalcitonin (TCT) helps regulate blood calcium levels. Reason (R): Parathyroid hormone (PTH) acts on bones to stimulate bone resorption.

With reference to parathyroid hormone (PTH), consider the following statements: 1. Its secretion is regulated by circulating sodium levels. 2. It increases bone resorption and renal reabsorption of calcium. 3. It increases calcium absorption from the digested food. Which of the statements given above are correct?

Which of the following are typical effects of catecholamines released from the adrenal medulla? 1. They decrease heart rate and strength of cardiac contraction. 2. Increased alertness and pupillary dilation. 3. Reduced respiratory rate and glycogen synthesis. Select the correct answer using the code below: