Question

How does the position of centromere from the basis of classification of chromosomes?​

Answer 1

Explanation:

Chromosomes are divided into four types based on the position of the centromere.

(i) Metacentric chromosome

The chromosomes in which the centromere is present in the middle and divides the

chromosome into two equal arms is known as a metacentric chromosome. During anaphase, they appear V-shaped.

ii) Sub-metacentric chromosome

The chromosome in which the centromere is slightly away from the middle region is known as a sub-metacentric chromosome. In this, one arm is slightly longer than the other. During anaphase, they appear L-shaped.

(iii) Acrocentric chromosome

The chromosome in which the centromere is located close to one of the terminal ends is known as an acrocentric chromosome. In this, one arm is extremely long and the other is extremely short. During anaphase, they appear J-shaped.

(iv) Telocentric chromosome

The chromosome in which the centromere is located at one of the terminal ends is known as a telocentric chromosome. During anaphase, they appear I-shaped.

Answer 2

Based on the position of centromere, monocentric chromosomes are four types.

1. Metacentric
2. Sub-metacentric
3. Acrocentric
4. Telocentric

$\huge{1) }$ $\sf\underline{ Metacentric }$

• Centromere present in the middle point of the chromosome.
• It is 'V' shaped and consists of 2 equal arms.

$\huge{2) }$ $\sf\underline{ Sub-metacentric }$ :-

• Centromere is slightly away from the centre of the chromosomes.
• It is 'L' shaped and consists of two unequal arms.

$\huge{3) }$ $\sf\underline{ Acrocentric }$ :-

• Centromere is situated at the subterminal position of a chromosome.
• It is 'J' shaped and consists of a very long arm and a very small arm.

$\huge{4) }$ $\sf\underline{ Telocentric }$ :-

• Centromere is situated at the terminal position of a chromosome.
• It is 'I' shaped and have only one arm.