MCQs on Chromatin and DNA Replication

The basic repeating structural unit of chromatin is:

• Histone

• Nucleosome

• Chromatosome

• Chromatid

Which histone is not part of the nucleosome core particle?

• H2A

• H3

• H1

• H4

The linker DNA in chromatin connects:

• Two histone H1 molecules

• Adjacent nucleosomes

• Chromatids

• Looped domains

Which level of chromatin organization is most condensed?

• 10 nm fiber

• 30 nm fiber

• Loop domains

• Metaphase chromosome

The charge on histone proteins is:

• Positive

• Negative

• Neutral

• Variable

Histone acetylation generally results in:

• Chromatin condensation

• Chromatin relaxation

• DNA degradation

• Nucleosome formation

Which histone variant is found in centromeric nucleosomes?

• H2AX

• CENP-A

• H3.3

• MacroH2A

Euchromatin is generally:

• Highly condensed and transcriptionally inactive

• Loosely packed and transcriptionally active

• Centromeric DNA only

• Found only in prokaryotes

DNA replication in *E. coli* begins at:

• oriT

• oriC

• ter site

• promoter region

Which enzyme unwinds the DNA double helix at the replication fork in prokaryotes?

• DNA gyrase

• Helicase

• Primase

• DNA ligase