Question

Imagine you've isolated a yeast mutant that contains histones resistant to acetylation. What phenotype do you predict for this mutant?

A. The mutant will grow rapidly
B. The mutant will show generally low levels of gene expression.
C. The mutant will show generally high levels of gene expression.
D. The mutant will show low levels of gene expression for only a few select genes.

Answer 1

The yeast mutant with histones resistant to acetylation is predicted to have generally low levels of gene expression, due to the inability of the DNA structure to relax and allow transcription machinery access.

Step-by-step explanation:

When considering the phenotype of a yeast mutant with histones resistant to acetylation, we must first understand the role of histone acetylation in gene expression. Histone acetylation typically relaxes the DNA structure, allowing transcription factors and RNA polymerase to access the DNA more readily, thereby increasing gene expression. Therefore, if the yeast mutant has histones that cannot be acetylated, the prediction would be that this would lead to a tighter packing of the DNA around the histones, making gene expression less accessible. This typically results in lower levels of gene transcription. Consequently, it is reasonable to predict that the mutant would show generally low levels of gene expression. So, the correct answer would be B. The mutant will show generally low levels of gene expression.