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Biology MCQs with Answer (part1) by General knowledge Solutions

Biology MCQs with Answer (part1)  by General knowledge Solutions

                                                                             






1. Number of amino acid residues in human growth hormone is
(A) 51
(B) 84
(C) 191
(D) 198

 2. Number of amino acid residues in prolactin is
(A) 51
(B) 84
(C) 191
(D) 198

3. Secretion of prolactin is regulated by
(A) Feedback inhibition
(B) Prolactin releasing hormone
(C) Prolactin release inhibiting hormone
(D) All of these

4. Precursor of ACTH is
(A) Cholesterol
(B) Pregnenolone
(C) Corticotropin
(D) Pro-opiomelanocortin

5. All of the following can be formed from pro-opiomelanocortin except
(A) α-and β-MSH
(B) β-and γ-Lipotropins
(C) α-and β-Endorphins
(D) FSH

6. All the following statements about proopiomelanocortin are true except
(A) It is made up of 285 amino acids
(B) It is synthesised in pars intermedia and anterior lobe of pituitary gland
(C) It is the precursor of ACTH and melatonin
(D) It is the precursor of corticotropin like intermediate lobe peptide and endorphins

7. All the following statements about ACTH are true except
(A) It is a tropic hormone
(B) Its target cells are located in adrenal cortex
(C) Its receptors are located in the cell membrane
(D) Its second messenger is inositol triphosphate

8. Regulation of ACTH secretion occurs through
(A) Corticotropin releasing hormone (CRH) and corticotropin release inhibiting hormone (CRIH) of hypothalamus
(B) Feedback inhibition by cortisol
(C) CRH and feedback inhibition by cortisol
(D) CRIH and feedback inhibition by cortisol

9. ACTH is a polypeptide made up of
(A) 39 amino acids
(B) 41 amino acids
(C) 51 amino acids
(D) 84 amino acids

10. CRH is a polypeptide made up of
(A) 39 amino acids
(B) 41 amino acids
(C) 51 amino acids
(D) 84 amino acids

11. Hormonal activity of ACTH is completely lost on removal of
(A) 5 C-terminal amino acids
(B) 10 C-terminal amino acids
(C) 15 C-terminal amino acids
(D) None of these

 12. All the following statements about TSH are true except
(A) It is a glycoprotein
(B) It is made up of α- and β-subunits
(C) Receptor recognition involves both the subunits
(D) Its subunit is identical with those of FSH and LH

 13. All the following statements about TSH are true except
(A) It is a tropic hormone
(B) It acts on para-follicular cells of thyroid glands
(C) Its receptors are membrane-bound
(D) Its second messenger is cyclic AMP

 14. All the following statements about thyrotropin releasing hormone are true except
(A) It is secreted by hypothalamus
 (B) It is a pentapeptide
(C) It increases the secretion of TSH
(D) Its secretion is inhibited by high level of T3 and T4 in blood

15. In males, luteinising hormone acts on
(A) Leydig cells
(B) Sertoli cells
(C) Prostate gland
(D) All of these

16. All the following statements about FSH are true except
(A) It is a tropic hormone secreted by anterior pituitary
(B) Its secretion is increased by gonadotropin releasing hormone
(C) It acts on Sertoli cells
 (D) It increases the synthesis of testosterone

17. In males, secretion of luteinising hormone is inhibited by
(A) Gonadotropin releasing hormone
(B) FSH
(C) High blood level of testosterone
(D) Inhibin

18. Secretion of luteinising hormone is increased by
(A) GnRH
(B) FSH
(C) Testosterone
(D) None of these

 19. In structure and function, HCG resembles
(A) FSH
(B) LH
(C) GnRH
(D) Progesterone

 20. Acromegaly results from overproduction of
(A) ACTH during childhood
(B) TSH during adult life
(C) Growth hormone during childhood
(D) Growth hormone during adult life

21. Acromegaly results in all the following except
(A) Overgrowth of the bones of face, hands and feet
(B) Increased stature
(C) Enlargements of viscera
(D) Impaired glucose tolerance

22. Overproduction of growth hormone during childhood causes
(A) Acromegaly
(B) Gigantism
(C) Cushing’s disease
(D) Simmond’s disease

23. Decreased secretion of growth hormone during childhood causes
(A) Simmond’s disease
(B) Cushing’s disease
(C) Dwarfism
(D) Cretinism

24. Stature is increased in
(A) Gigantism
(B) Acromegaly
(C) Simmond’s disease
(D) Cushing’s disease

25. An amino acid used for the synthesis of thyroid hormone is
(A) Tyrosine 
(B) Tryptophan 
(C) Histidine 
(D) Proline

26. An enzyme required for the synthesis of thyroid hormones is
(A) Iodinase
(B) Deiodinase
(C) Thyroperoxidase
(D) Thyroxine synthetase

27. Thyroperoxidase iodinates
(A) Free tyrosine in thyroid gland
(B) Tyrosine residues of thyroglobulin
(C) Tyrosine residues of thyroxine binding globulin
(D) Tyrosine residues of thyroxine binding prealbumin

28. In thyroxine, tyrosine residues are iodinated at positions:
(A) 1 and 3
(B) 2 and 4
(C) 3 and 5
(D) 4 and 6

29. Thyroid gland takes up circulating iodine
(A) By simple diffusion
(B) By facilitated diffusion
(C) By active uptake
(D) In exchange for chloride

30. Thyroid hormones are present in blood
(A) In free form
(B) In association with thyroxine binding globulin (TBG)
(C) In association with thyroxine binding prealbumin (TBPA)
(D) Mainly in association with TBG, partly in free form and sometimes in association with TBPA also

31. When thyroxine binding globulin and thyroxine binding pre-albumin are saturated with thyroxine, the excess hormone is transported by
(A) Albumin
(B) Gamma globulins
(C) Transcortin
(D) None of these

32. Receptors for thyroid hormones are present
(A) On the cell membrane
(B) Across the cell membrane
(C) Inside the cells
(D) In association with G-proteins

33. Binding of thyroxine to its receptors
(A) Activates Adenylate cyclase
(B) Activates guanylate cyclase
(C) Activates a stimulatory G-protein
(D) Increases transcription

34. The most powerful thyroid hormone is
(A) Reverse T3
(B) DIT
 (C) T3
(D) T4


35. The most abundant thyroid hormone in blood is
(A) Free T3
(B) T3 bound to TBG
(C) Free T4
(D) T4 bound to TBG

36. Secretion of thyroid hormones is regulated by
(A) Hypothalamus
(B) Anterior pituitary
(C) Feedback regulation
(D) All of these



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


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