Question

How are large DNA molecules enclosed compactly in the nucleus of a cell?

Answer 1

DNA molecules are compacted by wrapping around histones to form nucleosomes, which are then organized into a 30 nm fiber and loops to create a chromosome.

Step-by-step explanation:

In order to fit the long DNA molecules inside the nucleus of a cell, they are tightly packed using a process called compaction. The DNA is wrapped around proteins called histones to form structures called nucleosomes. Each nucleosome contains eight histone molecules, and the DNA wraps around them to become compacted. These nucleosomes are then organized close together to form a 30 nm fiber, which further compacts the DNA. The 30 nm fiber then forms loops that are bound together to create a chromosome.

Answer 2

It is supercoiled into A DNA (the most abundant type), sometimes into B DNA (Z DNA does not exist in a natural biosystem).

Supercoiled DNA is wrapped around histones and organized into chromosomes.