# DBT JRF 2022 — Question 11

Exam: DBT JRF 2022 · Section: A · Topic: Cell Biology › Chromatin & Nucleosome Structure · Difficulty: Medium

## Question

In eukaryotes, nucleosomes comprise of which one of the following histones?

## Options

- **A.** H1, H2A, H2B, and H3
- **B.** H2A, H2B, H3, and H4
- **C.** H1, H2B, H3, and H4
- **D.** H1, H2A, H3, and H4

## Answer

Option B

## Explanation

Nucleosome composition: The nucleosome core particle consists of: • A histone OCTAMER: two copies each of H2A, H2B, H3, and H4 (i.e., 8 histone molecules total) • ~147 bp of DNA wrapped ~1.75 turns around this octamer • H1 (linker histone): binds the DNA that enters and exits the nucleosome (linker DNA), stabilising higher-order chromatin structure — it is NOT part of the core octamer. Distinction: H1 is the LINKER histone; H2A, H2B, H3, H4 are the CORE histones. Answer: H2A, H2B, H3, and H4 (Option 2).

Source: https://mypyqbuddy.com/questions/in-eukaryotes-nucleosomes-comprise-of-which-one-of-6a104cd5920734408bc0c6e8