[Total Time: 2½]
[Total Marks: 75 ]
1) Attempt all questions.
2) All questions carry equal marks.
3) Draw neat labeled diagrams wherever necessary.
4) For Q2, Q 3, and Q4 attempt A and B OR C and D
Q.1) Do as directed: (Any fifteen) (15M)
1) A ____________ is a pre-existing polynucleotide-chain in DNA replication to which now
nucleotides can be added.
2) In DNA replication, ___________ exonuclease activity is a proof reading mechanism.
3) The segments of untwisted single-strands upon which the new strands are made are called _________strands.
4) In DNA replication, the ______________ proteins bind to the parental molecule at the origin of replication and wrap the DNA around them.
5) Primase activated by DNA helicases, synthesizer a short ____________ required for initiation of DNA synthesis.
6) The RNA primers themselves do not remain as a part of the new. DNA chain, they are removed and replaced with DNA by the action of ____________.
7) In eukaryotes, the enzyme ____________ serves a DNA repair function.
8) Define Mutation.
9) Give one example of an intercalating agent.
10) A ___________ mutation is a specific type of base pair substitution mutation involving a change from one purines pyrimidine base pair to other purine-pyrimidine base pair.
11) What are reverse mutations.
12) State the role of Rec A protein.
13) Name any one gene involved in Mismatch Repair.
14) The acronym PUC stands for_____________ .
15) State True or false Terminal transferase is used in homo-polymer tailing.
16) State True or false: Transduction is a transfer of genetic material between bacterial cells via a phage.
17) Name any one plant virus used as a vector.
18) Name the radioactive isotope of phosphorus used by Hershy and Chase…..
19) Give any one rule of ēnzyme polynucleotide kinase.
20) One Eukaryote used for cloning.
Q. 2) A) Discuss Meselson and Stahl’s experiment to prove the semiconservative nature of DNA replication in prokaryotes. (8M)
Q. 2) B) Explain Semi discontinuous DNA replication in prokaryotes. (7M)
Q. 2) C) Explain with a suitable diagram model of reciprocal recombination. (8M)
Q. 2) D) Explain the initiation of DNA replication in eukaryotes. (7M)
Q. 3) A) Define mutagen. Explain mutations caused by physical mutagens. (8M)
Q. 3) B) Explain photoreversal DNA repair. (7M)
Q. 3) C) Give the general classification of Mutations. (8M)
Q. 3) D Discuss Base excision DNA repair mechanism. (7M)
Q. 4) A) Describe Griffith’s experiment to prove that DNA is the genetic material. (8M)
Q. 4) B) How did scientists prove that RNA is the genetic material. (7M)
Q. 4) C) Write a note on various types of DNA polymerases. (8M)
Q. 4) D) Discuss identification of recombinant clones by direct screening. (7M)
Q. 5) Write Short notes on (Any three). (15M)
a) Rolling circle model of DNA replication.
b) Base analogs
c) Biological mutagen.
d) Expression vectors.
e) Reverse Trasncriptase.