- Which of the following is true about processed mRNA?
(a) It has 3 UTRs present between 5′cap and initiation
codon, inside exons and behind non-sense codon.
(b) It is polycistronic in eukaryotes.
(c) 1 st base at 5′ is 7 mG.
(d) Smallest RNA molecule taking part in protein synthesis.
- Which of the following is a true statement?
(a) Human genome has 16.5 million nucleosomes.
(b) 2-D shape of tRNA is ‘inverted L’.
(c) Aminoacyl attachment site of tRNA is 5′ primer with
base sequence CCA where amino acid attaches by
phosphoester bond.
(d) One nucleosome has 150 bps + octamer of histones.
- All the given statements are true, except.
(a) DNA is more stable than RNA because DNA contains 5
methyl uracil and deoxyribose.
(b) DNA replication is semi-conservative, bidirectional and
semi-discontinuous.
(c) Taylor proved semi-conservative replication of DNA by
working on E.coli bacteria.
(d) ‘Klenow fragment’ is a part of DNA polymerase I.
- Which of the following is incorrect for operon concept?
(a) The sequence of structural gene in lac operon is ZYA
where Z gene codes for hydrolytic enzyme.
(b) Allolactose turns it on by binding with repressor protein.
(c) It is an inducible operon and controls catabolic reactions.
(d) Operator gene receives RNA polymerase to switch it off.
- How many of the following statements are true?
(i) snRNA is synthesised by RNA polymerase III.
(ii) Proteins are synthesised from C′ → N′.
(iii) To form 1st peptide bond 4GTP and 3ATP are required.
(iv) Frame shift mutations are most dangerous.
(v) 23S rRNA acts as a catalyst in eukaryotic ribosome.
(a) 3 (b) 2 (c) 4 (d) 5
- Maximum possible transversion, which may take place in
genetic code are
(a) 366 (b) 183
(c) 549 (d) in each codon 9 only.
- Which of the following statements are false regarding ‘Hershey
and Chase’ experiment, proving DNA is a genetic material?
(i) They made use of rats.
(ii) Bacteriophage used was T 4 with dsDNA.
(iii) Used radioisotope to label sulphur with^35 S in sulphur
containing amino acids.
(iv) Technique used density gradient centrifugation.
(v) Phenomenon exploited was lytic cycle.
(a) (ii) and (iii) only (b) (iii) and (iv)
(c) (ii), (iii) and (iv) only (d) (i) and (ii)
- “Sequence annotation” in human genome project refers to
(a) identification of only those genes that are expressed as
RNA
(b) correlating, sequence of nucleotides already known for
an organism, to their functions
(c) selection of base sequences not involved in protein
synthesis
(d) both (a) and (b).
- DNA is a polymer of nucleotides which are linked to
each other by 3′ – 5′ phosphodiester bond. To prevent
polymerisation of nucleotides, which of the following
modifications would you choose?
(a) Replace purine with pyrimidines
(b) Remove/Replace 3′ OH group in deoxyribose
(c) Remove/Replace 2′ OH group with some other group
in deoxyribose
(d) Both (b) and (c)
- ‘Base pair rise’ in typical DNA molecule is
(a) 3.4 nm (b) 0.34 Å (c) 0.34 nm (d) 3.4 mm.
ANSWER KEY
- (a) 2. (a) 3. (c) 4. (b) 5. (d)
- (d) 7. (d) 8. (c) 9. (a) 10. (d)
- (b) 12. (c) 13. (b) 14. (a) 15. (a)
- (a) 17. (b) 18. (a) 19. (b) 20. (d)
- (b) 22. (d) 23. (d) 24. (d) 25. (a)
- (d) 27. (c) 28. (b) 29. (a) 30. (d)
- (c) 32. (c) 33. (b) 34. (a) 35. (c)
- (c) 37. (a) 38. (c) 39. (d) 40. (a)
- (a) 42. (d) 43. (b) 44. (b) 45. (c)
