Question

A chromosome carrying centromere at one end is
a. Acrocentric
b. Telocentric
c. Metacentric
d. Submetacentric.

Answer 1

Hint: In chromosome, centromere is the place or position where sister chromatids are divided into daughter chromosomes, based on the position of the centromere like where it is located they are classified into following types.

Complete answer:
 centromere is the constriction present on chromosome where two sister chromatids are held together where they are classified based on its position such as
- Metacentric
- Submetacentric
- Acrocentric
- Telocentric.
Metacentric: The chromosomes where centromere is located at the center and so that arms of chromosomes are in two equal sizes
> During metaphase, metacentric chromosome appear as v shape structure
> Metacentric chromosome is usually a primitive type of chromosomes present in primitive animals like amphibians
> In humans chromosomes 1 and 3 are metacentric chromosomes.
Submetacentric: In this type centromere is present at the center but not exactly at the center
> This results in the formation of unequal chromosomes like p arm and q arm
> They form the L shaped structures during the metaphase of chromosomes
> Most of the human chromosomes are submetacentric type
Acrocentric: centromere is located in such a position where it produces extremely short arm and a long arm
> In metaphase they show j shaped structures
> All acrocentric chromosomes are considered as sat chromosomes
> In humans 13,15,21 and 22 are sat acrocentric chromosomes
Telocentric: In chromosomes the centromere are present at the tip of chromosomes
> They are long rod shaped structures
> They appear as I shape during metaphase of cell cycle
> Telocentric chromosomes are rare in occurrence.

Note: Centromere is not only helpful in division, they provide a landmark for dividing chromosome into karyotype groups and also helpful for mapping the position of genes on chromosomes.