NEET Biology Chemical Coordination and Integration MCQs Set 07

Answer: (d) Progesterone Stimulate growth and activities of female secondary sex organs

Explanation:
1. Progesterone prepares and maintains the uterus for pregnancy; estrogen stimulates growth and activity of female secondary sex organs.
2. Therefore the match in option 4 is wrong.

Teacher's Note:
1. Estrogen: secondary sexual characters.
2. Progesterone: pregnancy.

Answer: (c) Adrenalin and Insulin

Explanation:
1. Adrenaline raises blood glucose (hyperglycaemic) and insulin lowers it (hypoglycaemic).
2. So adrenaline and insulin are the hyperglycaemic and hypoglycaemic pair respectively.

Teacher's Note:
1. Hypoglycaemic: insulin only.
2. Hyperglycaemic: glucagon, adrenaline, cortisol.

Answer: (b) a = ADH, c = axonal transport; b = TSH-releasing hormone, d = portal circulation

Explanation:
1. ADH is synthesised in the hypothalamus and reaches the posterior pituitary by axonal transport.
2. Releasing hormones such as TSH-RH reach the anterior pituitary through the portal circulation.

Teacher's Note:
1. Neural route: posterior lobe.
2. Portal route: anterior lobe.

Answer: (d) b, d

Explanation:
1. The thymus is linked to myasthenia gravis and the pancreas to prolonged hyperglycaemia (diabetes).
2. The pineal gland does not control metabolism and mental retardation, and the thyroid is not anti-inflammatory.

Teacher's Note:
1. Cortisol gives anti-inflammatory action.
2. Thymectomy relieves myasthenia gravis.

Answer: (d) Pregnancy support

Explanation:
1. The ruptured follicle becomes the corpus luteum, which secretes progesterone for pregnancy.
2. Libido, facial hair and voice depend on androgens.

Teacher's Note:
1. Progesterone supports pregnancy.
2. Estrogen helps female characters.

Answer: (b) Renin – Kidney, Relaxin – Placenta

Explanation:
1. Renin is secreted by the kidney and relaxin by the placenta (and ovary).
2. Calcitonin is from the thyroid, HCG from the placenta, and estrogen from ovary.

Teacher's Note:
1. ANF: atria.
2. Calcitonin: thyroid.

Answer: (a) Hypercalcemia

Explanation:
1. Parathormone raises blood calcium, causing hypercalcaemia when in excess.
2. It does not lower calcium.

Teacher's Note:
1. PTH is hypercalcaemic.
2. Calcitonin is hypocalcaemic.

Answer: (c) Thyroid

Explanation:
1. Thyroid hormones regulate BMR and body temperature.
2. Adrenal cortex, thymus and pituitary do not do this directly.

Teacher's Note:
1. T3 and T4: calorigenic.
2. Hypothyroidism: cold intolerance.

Answer: (b) Aldosterone

Explanation:
1. Aldosterone increases Na+ reabsorption and K+ excretion in the distal tubule.
2. Cortisol and prostaglandins do not do this mainly.

Teacher's Note:
1. Aldosterone: mineralocorticoid.
2. Controls electrolytes.

Answer: (a) Increased blood calcium level

Explanation:
1. Thyrocalcitonin is released when blood calcium rises.
2. It lowers calcium by reducing bone resorption.

Teacher's Note:
1. Rise in Ca2+ triggers TCT.
2. Fall in Ca2+ triggers PTH.

Answer: (b) Catecholamines

Explanation:
1. Catecholamines (adrenaline and noradrenaline) increase alertness, piloerection and sweating.
2. Cortisol and thymosin do not act this way.

Teacher's Note:
1. Medullary hormones.
2. Fast acting.

Answer: (c) Embryo develops normally till birth

Explanation:
1. From the second trimester the placenta produces enough progesterone.
2. So removal of the ovaries in the fourth month does not stop development.

Teacher's Note:
1. Placenta: endocrine organ.
2. Early pregnancy needs corpus luteum.

Answer: (a) Rickets and mongolism

Explanation:
1. Rickets is a vitamin D deficiency disease and mongolism is a chromosomal disorder, not hormonal.
2. The other pairs involve insulin, thyroxine or growth hormone.

Teacher's Note:
1. Down syndrome: trisomy 21.
2. Rickets: vitamin D.

Answer: (d) Estradiol

Explanation:
1. Relaxin, HCG and placental lactogen are protein hormones.
2. Estradiol is a steroid.

Teacher's Note:
1. Steroid: estradiol.
2. Protein: HCG.

Answer: (c) Ovary - Calcitonin

Explanation:
1. The ovary secretes estrogen and progesterone; calcitonin is made by the thyroid.
2. Therefore ovary-calcitonin is incorrect.

Teacher's Note:
1. Calcitonin: thyroid.
2. Inhibin: gonads.

Answer: (d) All of the above

Explanation:
1. Pituitary (adenohypophysis from Rathke's pouch, neurohypophysis from the brain), pineal and the lens of the eye all arise from ectoderm.
2. So all are ectodermal.

Teacher's Note:
1. Ectodermal derivatives.
2. Neural origin of pineal.

Answer: (c) Adrenal Cortex

Explanation:
1. The adrenal cortex arises from mesoderm.
2. Thymus, parathyroid and thyroid arise from endoderm.

Teacher's Note:
1. Cortex: mesoderm.
2. Medulla: ectoderm.

Answer: (c) Parathyroid hormone – Tetany

Explanation:
1. Deficiency of parathyroid hormone lowers blood calcium and causes tetany.
2. Relaxin does not cause gigantism, prolactin does not cause cretinism and insulin deficiency causes diabetes mellitus.

Teacher's Note:
1. PTH deficit: tetany.
2. Insulin deficit: DM.

Answer: (d) Luteinizing hormone–Failure of ovulation

Explanation:
1. LH is needed for ovulation, so its deficiency causes failure of ovulation.
2. Insulin deficiency gives diabetes mellitus, thyroxine deficiency gives cretinism or myxoedema.

Teacher's Note:
1. LH: ovulation.
2. PTH: calcium.

Answer: (b) Conn's disease

Explanation:
1. Conn's disease is primary hyperaldosteronism, excess mineralocorticoid independent of the renin-angiotensin system.
2. Cushing's is glucocorticoid excess.

Teacher's Note:
1. Conn: aldosterone excess.
2. Addison: deficiency.

Answer: (a) CAMP

Explanation:
1. cAMP is the second messenger that mediates the action of adrenaline in heart muscle.
2. cGMP often has the opposite effect.

Teacher's Note:
1. cAMP speeds contraction.
2. cGMP slows contraction.

Answer: (d) Gynaecomastia

Explanation:
1. Enlargement of breasts in males is gynaecomastia.
2. The other names are not valid terms.

Teacher's Note:
1. Gynaecomastia: male breast enlargement.
2. Linked to estrogen excess.