Question

In a typical eukaryotic cell, would you expect to find more molecules of the H1 histone or more molecules of the H2A histone? Explain your reasoning.

a. H1 histone due to its role in condensation
b. H2A histone for DNA repair
c. Equal distribution of H1 and H2A
d. Absence of both histones

Answer 1

In eukaryotic cells, there are more H2A histone molecules than H1 because the nucleosome core is composed of an octamer of histones including two molecules of H2A, while only one H1 molecule is associated with the linker DNA between nucleosomes.

Step-by-step explanation:

In a typical eukaryotic cell, you would expect to find more molecules of the H2A histone than the H1 histone. Each nucleosome contains eight histone molecules, two copies each of H2A, H2B, H3, and H4, which the DNA wraps around, resulting in a compact structure. In contrast, there is a single H1 histone that acts as a linker or a clamp, securing the DNA in place as it enters and exits the nucleosome. Since the nucleosome core consists of two molecules each of H2A, H2B, H3, and H4, and only one H1 molecule is associated with the linker DNA between nucleosomes, the number of H2A histones is inherently greater than that of H1 in the context of chromatin organization.