I. Start the exam by click the “Start” button
NUCLEIC ACIDS- Part 4
See all quizzes of NUCLEIC ACIDS- Part 4 here:
1 Gout is a metabolic disorder of catabolism
of
(A) Pyrimidine (B) Purine
(C) Alanine (D) Phenylalanine
2. Gout is characterized by increased plasma
levels of
(A) Urea (B) Uric acid
(C) Creatine (D) Creatinine
3. Lesch-Nyhan syndrome, the sex linked
recessive disorder is due to the lack of the
enzyme:
(A) Hypoxanthine-guanine phosphoribosyl
transferse
(B) Xanthine oxidase
(C) Adenine phosphoribosyl transferase
(D) Adenosine deaminase
4. Lesch-Nyhan syndrome, the sex linked,
recessive absence of HGPRTase, may lead
to
(A) Compulsive self destructive behaviour with
elevated levels of urate in serum
(B) Hypouricemia due to liver damage
(C) Failure to thrive and megaloblastic anemia
(D) Protein intolerance and hepatic encephalopathy
5. The major catabolic product of pyrimidines
in human is
(A) β-Alanine (B) Urea
(C) Uric acid (D) Guanine
6. Orotic aciduria type I reflects the deficiency
of enzymes:
(A) Orotate phosphoribosyl transferase and
orotidylate decarboxylase
(B) Dihydroorotate dehydrogenase
(C) Dihydroorotase
(D) Carbamoyl phosphate synthetase
7. Orotic aciduria type II reflects the deficiency
of the enzyme:
(A) Orotate phosphoribosyl transferase
(B) Orotidylate decarboxylase
(C) Dihydroorotase
(D) Dihydroorotate dehydrogenase
8. An autosomal recessive disorder, xanthinuria
is due to deficiency of the enzymes:
(A) Adenosine deaminase
(B) Xanthine oxidase
(C) HGPRTase
(D) Transaminase
9. Enzymic deficiency in β-aminoisobutyric
aciduria is
(A) Adenosine deaminase
(B) Xanthine oxidase
(C) Orotidylate decarboxylase
(D) Transaminase
10. Polysomes lack in
(A) DNA (B) mRNA
(C) rRNA (D) tRNA
11. Genetic information flows from
(A) DNA to DNA
(B) DNA to RNA
(C) RNA to cellular proteins
(D) DNA to cellular proteins
12. Genetic code is
(A) Collection of codon
(B) Collection of amino acids
(C) Collection of purine nucleotide
(D) Collection of pyrimidine nucleotide
13. Degeneracy of genetic code implies that
(A) Codons do not code for specific amino acid
(B) Multiple codons must decode the same amino
acids
(C) No anticodon on tRNA molecule
(D) Specific codon decodes many amino acids
14. Genetic code is
(A) Overlapping (B) Non-overlapping
(C) Not universal (D) Ambiguous
15. mRNA is complementary to the nucleotide
sequence of
(A) Coding strand (B) Ribosomal RNA
(C) tRNA (D) Template strand
16. In DNA replication the enzyme required
in the first step is
(A) DNA directed polymerase
(B) Unwinding proteins
(C) DNA polymerase
(D) DNA ligase
17. The smallest unit of DNA capable of coding
for the synthesis of a polypeptide is
(A) Operon (B) Repressor gene
(C) Cistron (D) Replicon
18. Termination of the synthesis of the RNA
molecule is signaled by a sequence in the
template strand of the DNA molecule, a
signal that is recognized by a termination
protein, the
(A) Rho (ρ) factor (B) σ factor
(C) δ factor (D) ε factor
19. After termination of the synthesis of RNA
molecule, the core enzymes separate from
the DNA template. The core enzymes then
recognize a promoter at which the synthesis
of a new RNA molecule commences,
with the assistance of
(A) Rho (ρ) factor (B) δ factor
(C) β factor (D) σ factor
20. In the process of transcription in bacterial
cells
(A) Initiation requires rho protein
(B) RNA polymerase incorporates methylated
bases in correct sequence
(C) Both the sigma unit and core enzymes of RNA
polymerase are required for accurate
promotor site binding
(D) Primase is necessary for initiation
21. The correct statement concerning RNA and
DNA polymerases is
(A) RNA polymerase use nucleoside diphosphates
(B) RNA polymerase require primers and add
bases at 5’ end of the growing polynucleotide
chain
(C) DNA polymerases can add nucleotides at both
ends of the chain
(D) All RNA and DNA polymerases can add
nucleotides only at the 3’ end of the growing
polynucleotide chain
22. The eukaryotic nuclear chromosomal DNA
(A) Is a linear and unbranched molecule
(B) Is not associated with a specific membranous
organelle
(C) Is not replicated semiconservatively
(D) Is about of the same size as each prokaryotic
chromoses
23. The function of a repressor protein in an
operon system is to prevent synthesis by
binding to
(A) The ribosome
(B) A specific region of the operon preventing
transcription of structural genes
(C) The RNA polymerase
(D) A specific region of the mRNA preventing
translation to protein
24. All pribnow boxes are variants of the
sequence:
(A) 5′–TATAAT –3′ (B) 5′–GAGCCA –3′
(C) 5′–UAACAA –3′ (D) 5′–TCCTAG –3′
25. 5’-Terminus of mRNA molecule is capped
with
(A) Guanosine triphosphate
(B) 7-Methylguanosine triphophate
(C) Adenosine triphosphate
(D) Adenosine diphosphate
26. The first codon to be translated on mRNA
is
(A) AUG (B) GGU
(C) GGA (D) AAA
27. AUG, the only identified codon for methionine
is important as
(A) A releasing factor for peptide chains
(B) A chain terminating codon
(C) Recognition site on tRNA
(D) A chain initiating codon
28. In biosynthesis of proteins the chain
terminating codons are
(A) UAA, UAG and UGA
(B) UGG, UGU and AGU
(C) AAU, AAG and GAU
(D) GCG, GCA and GCU
29. The formation of initiation complex during
protein synthesis requires a factor:
(A) IF-III (B) EF-I
(C) EF-II (D) IF-I
30. The amino terminal of all polypeptide
chain at the time of synthesis in E. coli is
tagged to the amino acid residue:
(A) Methionine (B) Serine
(C) N-formyl methinine (D) N-formal serine
