In a nucleosome, the DNA is wrapped around
a. Histones
b. Ribosomes
c. Polymerase molecules
d. A thymine dimer

Verified step by step guidance

1. Understand the structure of a nucleosome: A nucleosome is the basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound around a core of histone proteins.
2. Identify the components involved in DNA packaging: Histones are proteins that play a crucial role in the organization and packaging of DNA into nucleosomes.
3. Differentiate between the options given: Histones are the correct proteins associated with nucleosomes, whereas ribosomes, polymerase molecules, and thymine dimers have different functions in the cell.
4. Recall the function of histones: Histones help in compacting the DNA into a smaller volume, allowing it to fit within the cell nucleus and also play a role in gene regulation.
5. Conclude the correct answer: Based on the understanding of nucleosome structure and the role of histones, the DNA in a nucleosome is wrapped around histones.

Key Concepts

Nucleosome Structure

A nucleosome is the fundamental unit of chromatin, consisting of a segment of DNA wrapped around a core of histone proteins. This structure helps in compacting DNA within the nucleus and plays a crucial role in gene regulation. Understanding nucleosome structure is essential for grasping how DNA is organized and accessed in cells.

Histones

Histones are proteins that serve as spools around which DNA winds, forming nucleosomes. They are key components in the packaging of DNA into chromatin, influencing gene expression and DNA replication. Histones can undergo various modifications that affect chromatin structure and function, making them vital for understanding DNA accessibility.

DNA Packaging

DNA packaging refers to the process by which DNA is compacted to fit within the cell nucleus. This involves wrapping DNA around histones to form nucleosomes, which further coil and fold into higher-order structures. Effective DNA packaging is crucial for maintaining genome integrity and regulating gene expression, highlighting its importance in cellular function.