Human Karyotype

Humankaryotype,  chromosomes are divided into how many groups?

In a human karyotype, chromosomes are conventionally divided into 7 groups (A-G) based on their size and centromere position, along with the sex chromosomes (X and Y). 

• Groups A-G:

  These groups are formed based on the appearance of chromosomes under a microscope, particularly their size and the position of the centromere, which is the constricted region that holds sister chromatids together. 

• Group A (1-3): Large metacentric chromosomes.
• Group B (4-5): Large submetacentric chromosomes.
• Group C (6-12, X): Medium-sized submetacentric chromosomes. 
• Group D (13-15): Medium-sized acrocentric chromosomes. 
• Group E (16-18): Short submetacentric chromosomes. 
• Group F (19-20): Short metacentric chromosomes.
• Group G (21-22): Small acrocentric chromosomes.