Sense strand mcq for mcat prep?

Question

5-bromouracil resembles thymine enough to beceome incorporated into DNA during replication. once incorportated, however, it rearranges to resemble cytosine. if 5-bromouracil were present during the replication of the sense strand shown below, which of the following might be the sense strand formed in the following replication?

5-ggcgtacg-3

a.5-ggcgcacg-3

b.5-ggcgatcg-3

c.3-ccgcaggc-5

d.5-ggcgtgcg-3

any help would be appreciated. i am unsure on this one...and if anyone can help me via an explanation that'd be great

Answer 1

D is the answer.

There are two replications as indicated by the last line (the following replication)

The first replication would put a T where the A is, but this is when the error occurs, resulting in the C.

5-ggcgtacg-3

3-ccgcaTgc-5 should have been made

3-ccgcaCgc-5 actually made

Then the next replication puts the G where the C is.

3-ccgcaCgc-5

5-ggcgtGcg-3

Hope that helps you.