Question

What is centromere?

Answer 1

Hint: In the nucleus of cell DNA is found and DNA is compactly arranged in form of a chromatin net. At the time of the cell, division chromosomes appear. During metaphase, chromatin becomes more condensed form chromosomes. The number of chromosomes is different in organisms of different species. The structure of chromosomes is very specific.

Complete answer: Chromosomes at the time of cell division make two copies that are similar to each other. These are replicated chromosomes and both are called sister chromatids.
1. Both chromatids are attached to a site that is called the centromere. This is also called the primary constriction of chromosomes.
2. A centromere kinetochore is found. The kinetochore is the site where spindle fibers are attached to chromosomes during metaphase. At anaphase centromere that is joining the two sister chromatids, divides and separates. Chromatids are also separated and move towards opposite poles.
3. On the basis of the position of the centromere, chromosomes can be of 4 types-
a. Metacentric- In this type of chromosomes centromere is found in the mid part. Both arms of the chromosome are equal.
b. Submetacentric- When centromere is found away from the center of chromosomes. One arm of the chromosome is long and another one is short.
c. Acrocentric- when centromere is present at the sub-terminal part of the chromosome.
Febocentric- Centromere is found at the tip of the chromosome.

Additional Information:

Note: In centromere heterochromatin is found. This part shows a positive flugen reaction. Sometimes chromosome breaks and if the broken part lacks centromere, it will not exist without centromere and it will destroy.