Biology MCQs with Answer (part 1) by General knowledge Solutions

1. Hormones

(A) Act as coenzyme

(B) Act as enzyme

(D) Belong to B-complex group

2. Hormone that binds to intracellular receptor is

(A) Adrenocorticotropic hormone

(B) Thyroxine

(D) Glucagon

3. Hormone that bind to cell surface receptor and require the second messenger camp is

(A) Antidiuretic hormone

(B) Cholecystokinin

(D) Gastrin

4. A hormone secreted from anterior pituitary is

(A) Growth hormone

(B) Vasopressin

(D) Epinephrine

5. A hormone secreted from posterior pituitary is

(A) Vasopressin

(B) Thyrotropic hormone

(D) Adrenocorticotropic hormone

6. The number of amino acids in human growth hormone is

(A) 91

(B) 151

(D) 291

7. Growth hormone causes hyperglycemia. It is a result of

(A) Decreased peripheral utilization of glucose

(B) Decreased hepatic production via gluconeogenesis

(D) Decrersed lipolysis

8. Acromegaly results due to excessive release of

(A) Thyroxine

(B) Growth hormone

(D) Glucagon

9. Growth hormone is released by

(A) Somatostatin

(B) Growth hormone releasing hormone

(D) Luteinizing releasing hormone

10. The number of amino acids in prolactin is

(A) 134

(B) 146

(D) 199

11. Adrenocorticotropic hormone (ACTH) is a single polypeptide containing

(A) 25 amino acid

(B) 39 amino acid

(D) 52 amino acid

12. Biological activity of ACTH requires

(A) 10-N-terminal amino acid

(B) 24-N-terminal amino acid

(D) 15-C-terminal amino acid

13. ACTH stimulates the secretion of

(A) Glucocorticoids

(B) Epinephrine

(D) Luteinizing hormone

14. Excessive secretion of ACTH causes

(A) Cushing’s syndrome

(B) Addison’s disease

(D) Thyrotoxicosis

15. In Cushing’s syndrome-a tumour associated disease of adrenal cortex, there is

(A) Decreased epinephrine production

(B) Excessive cortisol production

(D) Decreased cortsoil production

16. ACTH induces rise in

(A) Cyclic AMP

(B) Cyclic GMP

(D) Magnesium

17. The circulating concentration of ACTH in plasma is

(A) 0.05 mµ/100 ml

(B) 0.1–2.0 mµ/100 ml

(D) 3.0–5.0 mµ/100 ml

18. Hyperglycemic effect of glucocorticoids is due to

(A) Inactivation of protein phosphatase

(B) Inactivation of fructose 1,6-biphosphatase

(D) Stimulation of synthesis of eltroxykinase

19. The predominant glucocorticoid is

(A) Cortisol

(B) Aldosterone

(D) Androstenedione

20. A specific cortisol binding protein, transcortin is a

(A) Albumin

(B) α1-Globulin

(D) β-Globulin

21. Cortisol is synthesized in

(A) Zona fasiculata

(B) Zona glomerulosa

(D) Chromaffin cells

22. All mammalian steroid hormones are formed from

(A) Purine

(B) Pyrimidine

(D) Pyrrole

23. A very efficient inhibitor of steroid biosynthesis is

(A) Aminoglutethimide

(B) Aminoimidazole

(D) Aminopterin

24. In adrenal gland the cholesterol is stored

(A) Mostly in the free form

(B) Mostly in esterified form

(D) Equal amounts of free and esterified form

25. Aldosterone synthesis occurs in

(A) Zona reticularis

(B) Zona fasciculata

(D) Chromaffian cells

26. In the biosynthesis of cortiol, the sequence of enzymes involved is

(A) Hydroxylase–dehydrogenase + isomerase – hydroxylase

(B) Dehydrogenase–hydroxylase–isomerase

(D) Isomerase–lyase–hydroxylase–dehydrogenase

27. The defect in adrenal cortex responsible for lack of glucocorticoids and mineralcorticoids is

(A) Androstenedione deficiency

(B) 17 α -OH progesterone deficiency

(D) Testosterone deficiency

28. 3-β-Hydroxysteroid dehydrogenase and ∆5,4 isomerase catalyse the conversion of the weak androgen DHEA to

(A) Androstenedione

(B) Testosterone

(D) Estrone

29. In the resting state plasma concentration of cortisol is

(A) 0.4–2.0 µg/100 ml

(B) 2.0–4.0 µg/100 ml

(D) 18.0–25.0 µg/100 ml

30. The most important effect of aldosterone is to

(A) Increase the rate of tubular reabsorption of sodium

(B) Decrease the rate of tubular reabsorption of potassium

(D) Decrease the renal reabsorption of sodium

31. One of the potent st imu lators of aldosterone secretion is

(A) Increased sodium concentration

(B) Decreased potassium concentration

(D) Increased ECF volume

32. In the rennin-angiotensin system the primary hormone is

(A) Angiotensinogen

(B) Angiotensin I

(D) Angiotensin III

33. Aldosterone release is stimulated by

(A) α2-Globulin

(B) Renin

(D) Growth hormone

34. In the synthesis of Angiotensin I, rennin acts on Angiotensinogen and cleaves the

(A) Leucine – leucine at 10 and 11 position

(B) Valine – tyrosine at 3 and 4 position

(D) Proline – histidine at 7 and 8 position

35. Catecholamine hormones are synthesized in the

(A) Chromaffin cells of adrenal medulla

(B) Zona glomerulosa of adrenal cortex

(D) Zona reticularis of adrenal cortex

36. Catecholamine hormones are

(A) 3, 4-Dihydroxy derivatives of phenylethylamine

(B) p-Hydroxy derivatives of phenylacetate

(D) p-Hydroxy derivatives of phenyllactate

37. The sequential steps in the conversion of tyrosine to epinephrine are

(A) Ring hydroxylation-decarboxylation-side chain hydroxylation-N-methylation

(B) Side chain hydroxylation-decarboxylation-ring hydroxylation N-methylation

(D) N-methylation-decarboxylation-ring and side chain hydroxylation

38. The hormone required for uterine muscle contraction for child birth is

(A) Progesterone

(B) Estrogen

(D) Vasopressin

39. The number of amino acids in the hormone oxytocin is

(A) 7

(B) 9

(D) 18

40. Vasopressin and oxytocin circulate unbound to proteins and have very short plasma half lives, on the order of

(A) 1–2 minutes

(B) 2–4 minutes

(D) 10–12 minutes

Answer

1. C 2. B 3. A 4. A 5. A 6. C 7. A 8. B 9. B 10. D 11. B 12. B 13. A 14. A 15. B 16. A 17. B 18. C 19. A 20. C 21. A 22. C 23. A 24. B 25. C 26. A 27. C 28. A 29. C 30. A 31. C 32. C 33. C 34. A 35. A 36. A 37. A 38. C 39. B 40. B

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Biology MCQs with Answer (part 1) by General knowledge Solutions