Question

Hydroxylamine converts cytosine (C) into hydroxylaminocytosine, which forms base pairs with adenine. Based on this information, all mutations induced by hydroxylamine should be:

A. Transition
B. Frameshift
C. Nonsense
D. Transversion
E. Null loss-of-function

Answer 1

Hydroxylamine-induced mutations where cytosine is replaced by adenine cause transition mutations, as a pyrimidine is replaced by another pyrimidine. The DNA structure is preserved due to base-pairing rules, but genetic code changes may occur if the mutation affects a coding region.

Step-by-step explanation:

When hydroxylamine converts cytosine into hydroxylaminocytosine, which pairs with adenine instead of guanine, the type of mutation induced is known as a transition. This is because a pyrimidine (cytosine) is replaced by another pyrimidine (thymine, which base pairs with adenine), and this does not alter the general structure of the DNA strand. In DNA repair, either the thymine dimers would be disrupted or the dimerized bases would be replaced with monomeric bases to correct such damage.

In the case of hydroxylamine-induced mutations where cytosine is replaced by adenine, the DNA structure remains largely intact as the base-pairing rule is followed, with adenine pairing with thymine. However, this base substitution can potentially lead to changes in the genetic code if the mutation occurs in a coding region of the DNA.