What is chromatin?

• A. Clusters of DNA, RNA, and proteins in the nucleus.
• B. A ribosome complex.
• C. A lipid storage particle.
• D. A mitochondrial subunit.

Answer: (A)

Chromatin is the material of chromosomes in the nucleus composed mainly of DNA wrapped around proteins called histones. This DNA–protein complex packs the long genome so it fits inside the nucleus and, at the same time, regulates access to genes by changing how tightly the DNA is wound. Before cell division, chromatin is less condensed and spread out to allow transcription; during division it condenses into visible chromosomes.

The statement describes chromatin as clusters of DNA, RNA, and proteins in the nucleus. The essential idea is DNA bound to proteins in the nucleus forming the material that becomes chromosomes. RNA isn’t a defining component of chromatin, though RNA can interact with chromatin in regulatory ways. The other options point to structures that are not chromatin: a ribosome complex (protein synthesis), a lipid storage particle, or a mitochondrial subunit.