Question

A heterochromatic region with fully methylated DNA and extensively modified histone H3 prior to DNA replication, will have ______ levels of these modifications in the daughter chromatids produced after DNA replication.

1) the same
2) 1/2
3) 1/4

Answer 1

A heterochromatic region with fully methylated DNA and extensively modified histone H3 will have the same levels of these modifications in the daughter chromatids produced after DNA replication.

Step-by-step explanation:

During DNA replication, the parent DNA molecule unwinds and each strand serves as a template for the synthesis of a new complementary strand. This process is semi-conservative, meaning that half of the parent DNA molecule is conserved in each of the two daughter DNA molecules.

In the case of a heterochromatic region with fully methylated DNA and extensively modified histone H3, the modifications are maintained in the daughter chromatids after DNA replication. Therefore, the levels of these modifications in the daughter chromatids produced after DNA replication will be the same.