Question

A scientist is studying the effects of a chemical she believes to be a mutagen in Drosophila. Her treatment results in a forward mutation phenotype. To understand the molecular nature of this mutation, she attempts to reverse the mutation by treating the Drosophila mutant with hydroxylamine. However, this treatment has no impact on the mutant phenotype. Among the possibilities given below, the type of forward mutation her new mutagen most likely caused is a

nonsense mutation.

silent mutation.

neutral mutation.

TA-to-CG transition.

Both A and C are correct.

Answer 1

The chemical mutagen used by the scientist most likely caused a type of mutation that is not a TA-to-CG transition, such as a nonsense or another mutation type not reversible by hydroxylamine.

Step-by-step explanation:

A mutation is a heritable change in the DNA sequence of an organism that can affect the phenotype. When a scientist studying Drosophila finds a forward mutation phenotype that cannot be reversed with hydroxylamine, it suggests that the mutagen might have caused a type of mutation that is not corrected by this chemical. Since hydroxylamine typically induces specific transitions such as CG to TA, it is often ineffective against other types of mutations such as nonsense mutations, silent mutations, or neutral mutations. The most likely type of forward mutation caused by the new mutagen, in this case, would not be a TA-to-CG transition because hydroxylamine didn't reverse it, which might suggest a nonsense mutation or any other mutation type not typically targeted by hydroxylamine.