Question

What makes up the protein component of a nucleosome core?

a. Histone H1 protein
b. Two tetramers of histone proteins
c. One tetramer of histone proteins
d. Eight different histone proteins

Answer 1

The nucleosome core is made up of an octamer of histone proteins, consisting of two tetramers of the histones H2A, H2B, H3, and H4. The correct answer is b. Two tetramers of histone proteins.

Step-by-step explanation:

The protein component of a nucleosome core is made up of an octamer of histone proteins. This octamer is composed of two molecules of each of four different histone proteins - H2A, H2B, H3, and H4. These histone proteins are basic and positively charged, and they enable the DNA to wrap around them due to the negative charge of the DNA's phosphate backbone. This forms a structure called a nucleosome, which resembles 'beads on a string' when viewed through an electron microscope.

Therefore, the correct answer to the question about what makes up the protein component of a nucleosome core is b. Two tetramers of histone proteins. Histone H1 is involved in the higher-order packaging of DNA, but it is not a part of the nucleosome core itself.

Answer 2

The correct answer is b. Two tetramers of histone proteins.

Step-by-step explanation:

Nucleosomes are made of eight histones, that can be divided into two tetramers. The first one is made of H3 and H4 histones, forming a dimer and the second one is made of H2A and H2B histones forming another dimer. Two dimers of each one are then linked, forming tetramers and finally, when these two are formed, they bind so that way they form the octamer.