I. Start the exam by click the “Start” button
NUCLEIC ACIDS- Part 9
See all quizzes of NUCLEIC ACIDS- Part 9 here:
1 The following coenzyme is required for
catabolism of pyrimidine bases:
(A) NADH (B) NADPH
(C) FADH2 (D) None of these
2. Inheritance of primary gout is
(A) Autosomal recessive
(B) Autosomal dominant
(C) X-linked recessive
(D) X-linked dominant
3. The following abnormality in PRPP
synthetase can cause primary gout:
(A) High Vmax
(B) Low Km
(C) Resistance to allosteric inihbition.
(D) All of these
4. All the following statements about
primary gout are true except
(A) Its inheritance is X-linked recessive
(B) It can be due to increased activity of PRPP
synthetase
(C) It can be due to increased activity of hypoxanthine
guanine phosphoribosyl transferase
(D) De novo synthesis of purines is increased in it
5. All of the following statements about uric
acid are true except
(A) It is a catabolite of purines
(B) It is excreted by the kidneys
(C) It is undissociated at pH above 5.8
(D) It is less soluble than sodium urate
6. In inherited deficiency of hypoxanthine
guanine phosphoribosyl transferase
(A) De novo synthesis of purine nucleotides is
decreased
(B) Salvage of purines is decreased
(C) Salvage of purines is increased
(D) Synthesis of uric acid is decreased
7. All of the following statements about uric
acid are true except
(A) It can be formed from allantoin
(B) Formation of uric acid stones in kidneys can
be decreased by alkalinisation of urine
(C) Uric acid begins to dissociate at pH above 5.8
(D) It is present in plasma mainly as monosodium
urate
8. All of the following statements about
primary gout are true except
(A) Uric acid stones may be formed in kidneys
(B) Arthritis of small joints occurs commonly
(C) Urinary excretion of uric acid is decreased
(D) It occurs predominantly in males
9. All of the following statements about
allopurinol are true except
(A) It is a structural analogue of uric acid
(B) It can prevent uric acid stones in the kidneys
(C) It increases the urinary excretion of xanthine
and hypoxanthine
(D) It is a competitive inhibitor of xanthine oxidase
NUCLEIC ACIDS 251
10. Orotic aciduria can be controlled by
(A) Oral administration of orotic acid
(B) Decreasing the dietary intake of orotic acid
(C) Decreasing the dietary intake of pyrimidines
(D) Oral administration of uridine
11. All of the following occur in orotic aciduria
except
(A) Increased synthesis of pyrimidine nucleotides
(B) Increased excretion of orotic acid in urine
(C) Decreased synthesis of cytidine triphosphate
(D) Retardation of growth
12. Inherited deficiency of adenosine deaminase
causes
(A) Hyperuricaemia and gout
(B) Mental retardation
(C) Immunodeficiency
(D) Dwarfism
13. Complete absence of hypoxanthine guanine
phospharibosyl transferase causes
(A) Primary gout (B) Immunodeficiency
(C) Uric acid stones (D) Lesh-Nyhan syndrome
14. Increased urinary excretion of orotic acid
can occur in deficiency of
(A) Orotate phosphoribosyl transferase
(B) OMP decarboxylase
(C) Mitochondrial ornithine transcarbamoylase
(D) Any of the above
15. All of the following can occur in Lesch-
Nyhan syndrome except
(A) Gouty arthritis
(B) Uric acid stones
(C) Retarted growth
(D) Self-mutiliating behaviour
16. Inherited deficiency of purine nucleoside
phosphorylase causes
(A) Dwarfism (B) Mental retardation
(C) Immunodeficiency (D) Gout
17. Deoxyribonucleotides are formed by
reduction of
(A) Ribonucleosides
(B) Ribonucleoside monophosphates
(C) Ribonucleoside diphosphates
(D) Ribonucleoside triphosphates
18. An alternate substrate for orotate
phosphoribosyl transferase is
(A) Allopurinol (B) Xanthine
(C) Hypoxanthine (D) Adenine
19. Mammals other than higher primates do
not suffer from gout because they
(A) Lack xanthine oxidase
(B) Lack adenosine deaminase
(C) Lack purine nucleoside phosphorylase
(D) Possess uricase
20. Hypouricaemia can occur in
(A) Xanthine oxidase deficiency
(B) Psoriasis
(C) Leukaemia
(D) None of these
21. Synthesis of DNA is also known as
(A) Duplication (B) Replication
(C) Transcription (D) Translation
22. Replication of DNA is
(A) Conservative (B) Semi-conservative
(C) Non-conservative (D) None of these
23. Direction of DNA synthesis is
(A) 5’ → 3’ (B) 3’ → 5’
(C) Both (A) and (B) (D) None of these
24. Formation of RNA primer:
(A) Precedes replication
(B) Follows replication
(C) Precedes transcription
(D) Follows transcription
25. Okazaki pieces are made up of
(A) RNA (B) DNA
(C) RNA and DNA (D) RNA and proteins
26. Okazaki pieces are formed during the
synthesis of
(A) mRNA (B) tRNA
(C) rRNA (D) DNA
27. After formation of replication fork
(A) Both the new strands are synthesized discontinuously
(B) One strand is synthesized continuously and
the other discontinuously
(C) Both the new strands are synthesized
continuously
(D) RNA primer is required only for the synthesis
of one new strand
28. An Okazaki fragment contains about
(A) 10 Nucleotides
(B) 100 Nucleotides
(C) 1,000 Nucleotides
(D) 10,000 Nucleotides
29. RNA primer is formed by the enzyme:
(A) Ribonuclease (B) Primase
(C) DNA polymerase I (D) DNA polymerase III
30. In RNA, the complementary base of adenine
is
(A) Cytosine (B) Guanine
(C) Thymine (D) Uracil
