Describe types and function of chromosomes

Subject: Zoology

Difficulty Level: Moderate
Types of chromosomes
Function of chromosomes

Updated by: Arabinda Naik

Answer:

Type of chromosome


Based on the number of centromeres present                                            

Monocentric: having only one centromere                                                              

Holocentric: having diffused centromere and microtubules are attached along the length of a chromosome                                                                  
Acentric: chromosome may break and fuse together to form a chromosome without a centromere. It cannot attach to the mitotic spindle.                

Dicentric: chromosomal aberration where chromosomes break and fuse together with two centromeres. They are also unstable as two centromeres tend to migrate to opposite poles resulting in fragmentation.
Based on the position of the centromere
 
Telocentric: rod-like chromosome with centromere presents on the proximal end. No ‘p’ arm or short arm of chromosome, is present. Telomeric chromosomes are not found in humans.
Acrocentric: rod-like, centromere present at one end giving rise to one very short arm and an exceptionally long arm
Submetacentric: L-shaped or J-shaped, with centromere near the centre of the chromosome giving rise to two unequal arms.
Metacentric: V-shaped chromosomes with centromere in the middle giving rise to two equal arms

Function of chromosomes


The main function of chromosomes is to carry the DNA and transfer the genetic information from parents to offspring. Chromosomes play an important role and act as a guiding force in the growth, reproduction, repair, and regeneration process, which is important for their survival. Chromosomes protect the DNA from getting tangled and damaged. Spindle fibres attached to the centromere help in the movement of the chromosome during cell division. Each chromosome contains thousands of genes that precisely code for multiple proteins present in the body.

 

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