The term cistorn, muton and recon were introduced by

1. The term cistorn, muton and recon were introduced by

(A) Watson and Crick
(B) S. Benzer
(C) Meselson
(D) Morgan
Answer: (B)

2. Extranuclear genetic material is found in

(A) Plastid and nucleus
(B) Mitochondria and plastids
(C) Nucleus and cytoplasm
(D) Mitochondria and nucleus
Answer: (B)

3. The molecular formulae of deoxyribose sugar and ribose sugar respectively are

(A) C5 H10 O4 and C5H10O6
(B) C5 H10 O4 and C5H10O5
(C) C5 H10 O5 and C5H10O4
(D) C5 H10 O5 and C6H10O4
Answer: (B)

4. The nitrogen bases which pair with two hydrogen bonds are

(A) Adenine and thymine
(B) Adenine and Cytosine
(C) Cytosine and guanine
(D) Cytosine and adenine
Answer: (A)

5. DNA differs from RNA in

(A) Presence of deoxyribose sugar
(B) Presence of thymine base
(C) Property of replication
(D) All the above
Answer: (D)

6. DNA molecules makes a complete turn after every

(A) 20 Å
(B) 34 Å
(B) 3.4 Å
(D) 10 base pairs
Answer: (D)

7. The distance between two successive nitrogenous base pairs is

(A) 34 Å
(B) 36 Å
(C) 20 Å
(D) 3.4 Å
Answer: (D)

8. In nucleoside, nitrogen base is attached to pentose sugar at

(A) Carbon – 1 of pentose sugar
(B) Carbon – 2  of pentose sugar
(C) Carbon – 4 of pentose sugar
(D) Carbon – 5 of pentose sugar
Answer: (A)

9. If the strand of DNA has 35 nucleotide how many phosphodiester bonds would exist

(A) 34
(B) 35
(C) 24
(D) 70
Answer: (A)

10. In eukaryotic DNA replication, lagging strand is formed by

(A) RNA fragments
(B) Okazaki fragments
(C) DNA fragments
(D) Nucleotide fragments
Answer: (B)

11. The enzyme DNA polymerase can work only in

(A) 3¢ ® 5¢ direction
(B) 5¢ ® 3¢ direction
(C) Both the direction
(D) 5¢ ® 5¢ direction
Answer: (B)

12. Enzyme required for removing RNA primer during DNA replication is

(A) DNA primase
(B) DNA ligase
(C) DNA polymerase I
(D) DNA polymerase III
Answer: (C)

13. During DNA replication, the reunion or recoiling of separated DNA strand is prevented by

(A) Helix destabilizing protein
(B) Single strnad binding protein
(C) Rep protein
(D) Both (A) and (B)
Answer: (D)

14. The enzyme that cuts the bonds of DNA molecule at the origin of replication is

(A) Endonuclease
(B) DNA polymerase
(C) DNA gyrase
(D) DNA ligase
Answer: (A)

15. Which of the following enzyme is required to release the tension imposed by uncoiling of strands?

(A) Endonuclease
(B) DNA ligase
(C) DNA gyrase
(D) DNA helicase
Answer: (C)

16. The cellular composition of m-RNA is

(A) 5-10%
(B) 3-5%
(C) 10-20 %
(D) 70-80%
Answer: (B)

17. Formation of mRNA from DNA is called

(A) Transformation
(B) Transduction
(C) Traslation
(D) Transcription
Answer: (D)

18. The ratio of purines and pyrimidines in mRNA is not 1:1 because the nitrogenous bases are

(A) Unpaired
(B) Paired
(C) Paired only in loops
(D) Paired in stems
Answer: (A)

19. The codons which may present at 3¢ end of mRNA

(A) UAA
(B) UAG
(C) UGA
(D) Any one of these
Answer: (D)

20. Which of the following is not tool of genetic engineering?

(A) Vectors
(B) Enzymes
(C) Foreign DNA
(D) GMO
Answer: (D)

21. In recombinant DNA technology a plasmid vector is cleaved by

(A) Modified DNA ligase
(B) A heated alkaline solution
(C) The same enzyme that cleave the donor DNA
(D) The different enzyme other than that cleave the donor DNA
Answer: (C)

22. The most common plasmid vector used in genetic engineering is

(A) PBR 328
(B) PBR 322
(C) PBR 325
(D) PBR 330
Answer: (B)

23. ‘Nif gene’ for nitrogen fixation is cereal crops like wheat, jowar etc. is introduced by cloning

(A) Rhizobium meliloti
(B) Bacillus thuringiensis
(C) Rhizopus
(D) Rhizophora
Answer: (A)

24. Eco RI is an

(A) Ligase
(B) Polymerase
(C) Restriction enzyme
(D) Gyrase
Answer: (C)

25. The transgenic plant flavr savr tomato carries an artificial gene for

(A) Delay ripening process
(B) Longer shell life
(C) Added flavours
(D) All of these
Answer: (D)