DNA Structure and Replication
In DNA, there are

three bases known as adenine, guanine and cytosine
only two bases known as adenine and cytosine
five bases known as adenine, guanine, thymine, tryptophan and cytosine
four bases known as adenine, guanine, thymine and cytosine

ANSWER DOWNLOAD EXAMIANS APP

DNA Structure and Replication
The rapid appearance of HIV-1 strains that are resistant to AIDS drugs is due in part to which of the following property of its reverse transcriptase?

AZT (zidovudine) is too expensive to be taken in effective doses
It lacks a proofreading exonuclease
It has low affinity for the correct dNTP's
The RNase H domain of p66 causes error prone synthesis

ANSWER DOWNLOAD EXAMIANS APP