BIOCHEMISTRY
1. A nucleoside consists of
(A) Nitrogenous base
(B) Purine or pyrimidine base + sugar
(C) Purine or pyrimidine base + phosphorous
(D) Purine + pyrimidine base + sugar + phosphorous
2. A nucleotide consists of
(A) A nitrogenous base like choline
(B) Purine + pyrimidine base + sugar +phosphorous
(C) Purine or pyrimidine base + sugar
(D) Purine or pyrimidine base + phosphorous
3. A purine nucleotide is
(A) AMP
(B) UMP
(C) CMP
(D) TMP
4. A pyrimidine nucleotide is
(A) GMP
(B) AMP
(C) CMP
(D) IMP
5. Adenine is
(A) 6-Amino purine
(B) 2-Amino-6-oxypurine
(C) 2-Oxy-4-aminopyrimidine
(D) 2, 4-Dioxypyrimidine
6. 2, 4-Dioxypyrimidine is
(A) Thymine
(B) Cystosine
(C) Uracil
(D) Guanine
7. The chemical name of guanine is
(A) 2, 4-Dioxy-5-methylpyrimidine
(B) 2-Amino-6-oxypurine
(C) 2-Oxy-4-aminopyrimidine
(D) 2, 4-Dioxypyrimidine
8. Nucleotides and nucleic acids concentration are often also expressed in terms of
(A) ng
(B) mg
(C) meq
(D) OD at 260 nm
9. The pyrimidine nucleotide acting as the high energy intermediate is
(A) ATP
(B) UTP
(C) UDPG
(D) CMP
10. The carbon of the pentose in ester linkage with the phosphate in a nucleotide structure is
(A) C1
(B) C3
(C) C4
(D) C5
11. Uracil and ribose form
(A) Uridine
(B) Cytidine
(C) Guanosine
(D) Adenosine
12. The most abundant free nucleotide in mammalian cells is
(A) ATP
(B) NAD
(C) GTP
(D) FAD
13. The mean intracellular concentration of ATP in mammalian cell is about
(A) 1 mM
(B) 2 mM
(C) 0.1 mM
(D) 0.2 mM
14. The nucleic acid base found in mRNA but not in DNA is
(A) Adenine
(B) Cytosine
(C) Guanine
(D) Uracil
15. In RNA molecule ‘Caps’
(A) Allow tRNA to be processed
(B) Are unique to eukaryotic mRNA
(C) Occur at the 3’ end of tRNA
(D) Allow correct translation of prokaryotic mRNA
16. In contrast to eukaryotic mRNA, prokaryotic mRNA
(A) Can be polycistronic
(B) Is synthesized with introns
(C) Can only be monocistronic
(D) Has a poly A tail
17. The size of small stable RNA ranges from
(A) 0–40 nucleotides
(B) 40–80 nucleotides
(C) 90–300 nucleotides
(D) More than 320 nucleotides
18. The number of small stable RNAs per cell ranges from
(A) 10–50,000
(B) 50,000–1, 00,000
(C) 1, 00,000–10, 00,000
(D) More than 10 lakhs
19. Molecular weight of heterogenous nuclear RNA (hnRNA) is
(A) More than 107
(B) 105 to 106
(C) 104 to 105
(D) Less than 104
20. In RNA molecule guanine content does not necessarily equal its cytosine content nor does its adenine content necessarily equal its uracil content since it is a
(A) Single strand molecule
(B) Double stranded molecule
(C) Double stranded helical molecule
(D) Polymer of purine and pyrimidine ribonucleotides
21. The nitrogenous base present in the RNA Molecule is
(A) Thymine
(B) Uracil
(C) Xanthine
(D) Hypoxanthine
22. RNA does not contain
(A) Uracil
(B) Adenine
(C) Thymine
(D) Ribose
23. The sugar moiety present in RNA is
(A) Ribulose
(B) Arabinose
(C) Ribose
(D) Deoxyribose
24. In RNA molecule
(A) Guanine content equals cytosine
(B) Adenine content equals uracil
(C) Adenine content equals guanine
(D) Guanine content does not necessarily equal Its cytosine content.
25. Methylated purines and pyrimidines are Characteristically present in
(A) mRNA
(B) hnRNA
(C) tRNA
(D) rRNA
26. Thymine is present in
(A) tRNA
(B) Ribosomal RNA
(C) Mammalian mRNA
(D) Prokaryotic mRNA
27. The approximate number of nucleotides in tRNA molecule is
(A) 25 (B) 50
(C) 75 (D) 100
28. In every cell, the number of tRNA molecules is at least
(A) 10 (B) 20
(C) 30 (D) 40
29. The structure of tRNA appears like a
(A) Helix
(B) Hair pin
(C) Clover leaf
(D) Coil
30. Although each specific tRNA differs from the others in its sequence of nucleotides, all tRNA molecules contain a base paired stem that terminates in the sequence CCA at
(A) 3′Termini
(B) 5′ Termini
(C) Anticodon arm
(D) 53 ′′ -Termini
31. Transfer RNAs are classified on the basis of the number of base pairs in
(A) Acceptor arm
(B) Anticodon arm
(C) D arm
(D) Extra arm
32. In tRNA molecule D arm is named for The presence of the base:
(A) Uridine
(B) Pseudouridine
(C) Dihydrouridine
(D) Thymidine
33. The acceptor arm in the tRNA molecule has
(A) 5 Base pairs
(B) 7 Base pairs
(C) 10 Base pairs
(D) 20 Base pairs
34. in tRNA molecule, the anticodon arm Possesses
(A) 5 Base pairs
(B) 7 Base pairs
(C) 8 Base pairs
(D) 10 Base pairs
35. The T ψC arm in the tRNA molecule Possesses the sequence
(A) T, pseudouridine and C
(B) T, uridine and C
(C) T, dihydrouridine and C
(D) T, adenine and C
36. Double helical structure model of the DNA Was proposed by
(A) Pauling and Corey
(B) Peter Mitchell
(C) Watson and Crick
(D) King and Wooten
37. DNA does not contain
(A) Thymine
(B) Adenine
(C) Uracil
(D) Deoxyribose
38. The sugar moiety present in DNA is
(A) Deoxyribose
(B) Ribose
(C) Lyxose
(D) Ribulose
39. DNA rich in A-T pairs have
(A) 1 Hydrogen bond
(B) 2 Hydrogen bonds
(C) 3 Hydrogen bonds
(D) 4 Hydrogen bonds
40. In DNA molecule
(A) Guanine content does not equal cytosine content
(B) Adenine content does not equal thymine content
(C) Adenine content equals uracil content
(D) Guanine content equals cytosine content
41. DNA rich in G-C pairs have
(A) 1 Hydrogen bond
(B) 2 Hydrogen bonds
(C) 3 Hydrogen bonds
(D) 4 Hydrogen bonds
42. The fact that DNA bears the genetic information of an organism implies that
(A) Base composition should be identical from species to species
(B) DNA base composition should charge with age
(C) DNA from different tissues in the same organism should usually have the same base composition
(D) DNA base composition is altered with nutritional state of an organism
43. The width (helical diameter) of the double helix in B-form DNA in nm is
(A) 1 (B) 2
(C) 3 (D) 4
44. The number of base pair in a single turn Of B-form DNA about the axis of the molecule is
(A) 4
(B) 8
(C) 10
(D) 12
45. The distance spanned by one turn of Bform DNA is
(A) 1.0 nm
(B) 2.0 nm
(C) 3.0 nm
(D) 3.4 nm
46. In a DNA molecule the thymine concentration is 30%, the guanosine concentration will be
(A) 10%
(B) 20%
(C) 30%
(D) 40%
47. IN a DNA molecule, the guanosine content is 40%, the adenine content will be
(A) 10%
(B) 20%
(C) 30%
(D) 40%
48. An increased melting temperature of duplex DNA results from a high content of
(A) Adenine + Guanine
(B) Thymine + Cytosine
(C) Cytosine + Guanine
(D) Cytosine + Adenine
49. A synthetic nucleotide analogue, 4-hydro-xypyrazolopyrimidine is used in the treatment of
(A) Acute nephritis
(B) Gout
(C) Cystic fibrosis of lung
(D) Multiple myeloma
50. A synthetic nucleotide analogue, used in The chemotherapy of cancer and viral infections is
(A) Arabinosyl cytosine
(B) 4-Hydroxypyrazolopyrimidine
(C) 6-Mercaptopurine
(D) 6-Thioguanine
Answers
