FREE NEET Biology Practice MCQ Test: Chemical Coordination And Integration Exercise 4 Questions Answers With Detailed Explanations [PDF]

Answer: (c)

Answer: (b)

Answer: (a)

Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts. Gastrointestinal tracts secretes four major peptide hormones – gastrin, secretin, cholecystokinin (CCK) and gastric inhibitory peptide (GIP) while juxtaglomerular cells of kidney secretes erythropoietin, a peptide hormone. Releasing and inhibitory hormones are produced by hypothalamus. Neurohypophysis or posterior pituitary is under direct neural regulation of the hypothalamus.

Answer: (d)

Answer: (a)

Relaxin hormone is secreted by ovary and placenta during pregnancy, which relaxes ligaments in pelvis and softens and widens cervix during childbirth. Inhibin secreted by granulosa cells in the ovaries inhibits secretion of FSH by anterior pituitary. Thus, relaxin and inhibin have different functions and are not antagonistic.

Answer: (b)

Cortisol is secreted by the middle region of adrenal cortex. It increases the blood glucose level (which is anti-insulin effect) by converting proteins & fats into glucose.

Answer: (c)

Answer: (b)

Gonadotrophic hormones are secreted by anterior lobe of pituitary gland. They are as follows: (i) Follicle-stimulating hormone (FSH): It stimulates growth of ovarian follicles and their secretion of estrogens in the female, and spermatogenesis (formation of sperms) in the male. (ii) Interstitial cell stimulating hormone (ICSH): It activates the Leydig's (interstitial) cells of the testis to secrete androgens. In female, it stimulates the corpus luteum of the ovary to secrete progesterone. In female it is termed luteinizing hormone (LH).

Answer: (c)

Answer: (c)

Answer: (c)

Calcitonin or thyrocalcitonin is secreted by parafollicular cells of thyroid stroma. It retards bone dissolution and stimulates excretion of calcium in urine. Thus, it lowers calcium level in extracellular fluid (ECF). Parathormone is secreted by chief cells of parathyroid gland and is also known as Collip's hormone. It maintains blood calcium level by increasing its absorption from food in intestine and its reabsorption from nephrons in the kidney. Maintenance of proper calcium level is in fact, a combined function of parathormone and calcitonin. When calcium level falls below normal parathormone maintains it by promoting its absorption, reabsorption and also by demineralisation of bones. When blood calcium level exceeds above normal, then calcitonin hormone increases excretion of calcium in urine.

Answer: (c)

Answer: (c)

Answer: (d)

Cortisole is the steroid hormone secreted by adrenal cortex and plays an important role in carbohydrate metabolism. It retards the glucose consumption & hence level of glucose in blood increases & blood pressure increases.

Answer: (a)

In both females and males, inhibin inhibits FSH production. In females, FSH stimulates the secretion of inhibin from the granulosa cells of the ovarian follicles in the ovaries. In turn, inhibin suppresses FSH. In males, androgens stimulate inhibin production. It is secreted from the Sertoli cells, located in the seminiferous tubules inside the testes.

Answer: (b)

Answer: (d)

Answer: (d)

Answer: (a)

Answer: (c)