To study the chromosomal sets (Karyotype) of a normal female human.
Karyotyping is based on the size and position of chromosomes and centromeres,
respectively. It was first developed by Albert Levan in 1960. Based on the
centromeric position that is on the length of arms of chromosomes, he divided
- 1, 2, 3, 16, 19, and 20 - Metacentric
- 4–12, 17, 18, and X - Submetacentric
- 13–15, 21, 22, and Y - Telocentric
Later, Pataii classified the chromosomes into different families (Groups):
- Group A: 1-3 Chromosomes-Metacentric; longer than the all other
- Group B: 4 and 5 Chromosomes-Submetacentric
- Group C: 6-12 and X Chromosomes-Submetacentric
- Group D: 13-15 Chromosomes-Acrocentric
- Group E: 16-18 - Chromosomes-16: Metacentric, 17 and 18: Submetacentric
- Group F: 19 and 20 Chromosomes-Metacentric, comparatively smaller
- Group G: 21, 22 and Y Chromosomes-Acrocentric and the smallest in size
- The chromosomes of groups D and G have secondary constrictions.