Q. 30 - Biology

Question

Eukaryotic chromosomes are thousands of times longer than a typical cell. Explain how chromosomes can fit inside a eukaryotic nucleus.

Step-by-Step Solution

Answer

DNA forms nucleosome by coiling itself and the nucleosome is again further coiled making the chromosomes to fit inside a eukaryotic nucleus.

Step 1: Introduction

The eukaryotic cell differs from a prokaryotic cell majorly due to the presence of a membrane-bound nucleus. This nucleus stores all the genetic information (DNA) of the cell. 

Step 2: Explanation

DNA is too long to fit inside the cell, but it is very thin. Eukaryotic cells possess a protein octamer called Histones. So the DNA coils around the histones to form a coiled structure called "nucleosome". The winding of such long DNA around the histone proteins makes it a compact structure that can easily fit inside the nucleus.
During cell division, this nucleosome further coils around itself to become more compact and form the chromosome.