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Which of the following statement about fructose is true ?

A) Most predominant conformation of fructose in solution is 8 - fructopyranose
B) In polysaccharides, fructose is seen in their furanose form

C) Fructose is hygroscopic

D) All of the above

The linking number of DNA

A) 15 a topological property

B) Determines the degree of supercoiling
C) Is the sum of Twist (Tw) and Writhe (Wr)
D) All the above

The Klenow fragment of DNA polymerase | has
A) 5’- 3' exonuclease activity 8) 3’- 5’ exonuclease activity
C) Very high processivity D) Helicase activity

The role of 670 (sigma-70) in prokaryotic transcription is
A) Binding DNA template

B) Binding regulatory sequences

C) Forming phosphodiester bonds

D) Recognizing the promoter and initiating RNA synthesis

Eukaryotic RNA polymerase || transcribes
A) 18s rRNA B) tRNA C) mRNA D) 5s rRNA

Which of the following statement is incorrect regarding splicing ?

A) Splicing is accomplished by two transesterification reactions

B) At the end of splicing, the intron is released in the form of a lariant

©) The 2’ ~ OH of the adenine at the branch site attacks the 3’ - splice site
0) snRNAs in spliceosome catalyze the splicing of mRNA precursors

Lac repressor protein in the absence of inducer binds to the operator and thereby
A) Activates transcription B) Blocks transcription
C) Attenuates transcription D) None of the above

The phenomenon by which some t-RNA molecules recognize more than one codon 18
because of
A) Watson-Crick base pairing B) Wobble base pairing

C) Hoogsteen base pairing D) Purine-purine base pairing

Shine-Dalgarno sequence is

A) Centered about 10 nucleotides on the 5’ side of the initiator codon
B) A part of prokaryotic m-RNA

C) A purine rich region

D) All the above

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