Question

In yeast, which of these is NOT a function of MAT genes? O MATaallele encoding a regulatory protein (a2) that represses expression of a specific genes O MATa locus encoding a regulatory protein (a1) that affects only diploid cells O MATa locus encoding a regulatory protein (a1) that affects both haploid and diploid cells O controlling the expression of genes in a and a cells

Answer 1

QUESTION 1

The false statement is MATa locus encoding a regulatory protein (a1) that affects both haploid and diploid cells. In this case a2 and a1 will form a heterodimeric complex to repress the transcription of the HO locus. However, these proteins are expressed only in diploid cells which means that the repression of HO will occur only in diploid cells and not on haploid cells.

QUESTION 2

The correct answer is the changing of nucleosome position. Remember that the nucleosome is the fundamental unit of the chromatin and in the process of the chromatin remodeling, the nucleosomes will undergo certain modifications to allow the regulatory proteins to enter into the genomic DNA, in this way controlling the expression of genes.

QUESTION 3

2 alleles, MATa or MATα.