Question

The association of histone H₁ with a nucleosome indicates

• A. Transcription is occurring
• B. DNA replication is occurring
• C. The DNA is condensed into a Chromatin Fibre
• D. The DNA double helix is exposed

Answer 1

The correct option is C

The DNA is condensed into a Chromatin Fibre

The correct option is C

Explanation of the correct option:

1. The presence of histone H₁ implies that nucleosomes have completed their synthesis.
2. Histone has a positive moiety that binds to DNA that is negatively charged.
3. A single DNA molecule of tremendous length exists in the eukaryotic chromosome.
4. The DNA is linked to a vast number of protein molecules called chromatin.
5. When histone H₁ binds to a nucleoside, it means the DNA has been condensed into a chromatin fibre.

Explanation of the incorrect option:

Option A:

During transcription, there is no evidence of histone H₁ binding to a nucleosome.

Option B:

During DNA replication, histone H₁ does not associate with a nucleosome.

Option D:

The presence of histone H₁ on a nucleosome does not imply that the DNA helix is exposed.

Final answer: The association of histone H₁ with a nucleosome indicates the DNA is condensed into a Chromatin Fibre.