Biology DNA help please

Question

Which does not describe a function of the DNA polymerase molecule?

A) Recognize the free nucleotide that pairs with the base on the template strand of DNA

B) Read the strand of template DNA and recongnize the base there

C) proofread to ensure that the proper base has been incorporated

D) Make the proper nucleotide to match with the base read on the template strand

E) Cut out an improperly paired nucleotide and replace it with the proper one

Answer 1

It's definitely D.  

The nucleotides are already floating around in the cytoplasm.   All the polymerase does is basically everything else, ABCandE.  

Answer 2

E) Cut out an improperly paired nucleotide and replace it with the proper one

Answer 3

D) Make the proper nucleotide

A and B are obviously necessary, C and E both refer to the proofreading function of the polymerase, and D just doesn't fit - DNA polymerase does not make nucleotides.

Answer 4

Clarification on C:

DNA polymerase is like a little fist gripping the DNA helix (at this point, it's a single stranded helix, since DNA helicase has opened it up in order to replicate a single strand).  This structure is important because only correctly paired bases can pass through it.  If there's a mismatch, the double helix can't get through the upper part of the clenched hand, between the thumb and forefinger.  This represents the first of many proofreading mechanisms during replication.

The function described in E is carried out by nucleases (endo- or exo-, depending on where the nucleotide is that needs to be excised).