Question

C. Long Answer Type Questions
1. With the help of a diagram, write about different types
of chromosomes based on the position of centromere.
(2007)
2. Discuss in brief the replication of DNA.
3. Draw a diagram to depict structure of chromosome.
4. Give the functions of centromere.
5. Chromatin fibre is said to represent 'beads on a string'
structure. Explain.

tell me answer please​

Answer 1

Explanation:

The type of chromosomes based on the position of centromere are of the following four types :

1) Metacentric chromosome: centromere in middle forming two equal arms.

2) Sub-metacentric chromosome: centromere placed near to one end resulting in one shorter and one long arm.

3) Acrocentric chromosome: Centromere placed close to one end forming one extreme short and one extreme long arm.

4) Telocentric chromosome: terminally placed centromere.

solution

Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. ... Each time a cell divides, the two resulting daughter cells must contain exactly the same genetic information, or DNA, as the parent cell.

The centromeres are the point of attachment of the kinetochore. The main functions include the attachment of sister chromatids, and it is the site for attachment of spindle fibre. Centromeres help in the proper alignment and segregation of the chromosomes during the process of cell division in eukaryotic cells.

Chromatin is a complex of DNA and protein found in eukaryotic cells. Its primary function is packaging long DNA molecules into more compact, denser structures. ... DNA wraps around histone proteins, forming nucleosomes and the so-called "beads on a string" structure (euchromatin).