Question

What is a chromosome? Draw a labelled diagram of structure of the eukaryotic chromosome.

Answer 1

Hint: Chromosomes are the structures having an X like shape and they are packed in a condensed from inside the nucleus of the cell. The genetic information of the cell is contained inside the chromosome. The chromosomes are responsible for transferring genetic information from parent to the offspring.

Complete answer:
The chromosomes are generally a thread like structure which is packed inside the nucleus of the cell very densely and it is heavily coiled. The chromosome is made up of DNA of the cell and one protein unit which is known as histone. The thread like DNA of the individual is coiled around the histone protein unit.
The chromosome has a center point which is known as the centromere and this centromere divides the chromosome into two parts which are, upper part and the lower part. The shape of a chromosome is like an X. The upper part of the chromosome is called the P arm and the lower part is called the Q arm. The length of the p arm is shorter than the q arm.
We have discussed that the chromosome is having a protein onto which the DNA is coiled, the protein’s function is to provide support to the DNA molecule so that it can coil properly. The visualization of DNA is a complex process and it cannot be seen with the help of a microscope. For the observation of the chromosome one has to first decondense the DNA and then only the chromosome will be visible.

Note:
During the process of gametogenesis in the sexual reproduction, the genetic material which is the chromosome gets doubled up and it is sent to the gametes so that when the fusion will occur or the cell grows then the genetic integrity between the parents and offspring is maintained. The duplication of genetic material is done with the help of mitosis process.