(23 pairs)
Current Stage
Interphase
The parent cell has 46 chromosomes (23 pairs). DNA has already been replicated. Each chromosome now consists of two sister chromatids.
(2^23 = 8+ million!)
Sources of Variation
1. Independent Assortment: Chromosome pairs line
up randomly during Metaphase I
2. Crossing Over: Homologous chromosomes exchange
DNA segments during Prophase I
These two processes create trillions of possible genetic
combinations!