ZingPath: Genetics and Biotechnology

Explain independent assortment in meiosis.

~ During gamete production in humans, independent assortment of the 23 chromosome pairs occurs. This means that it is random which member of each chromosome pairs ends up in each gamete. This assortment can produce 8,388,608 different chromosome combinations. Considering just this factor alone, each human male or female can produce 8,388,608 genetically different gametes.

Explain crossing over in meiosis.

~ Crossing over is a process that occurs during prophase I of meiosis. Homologous chromosomes pair up and can swap matching regions of DNA. This can move genes, or regions of DNA, from one chromosome to its homologous pair. When this is combined with independent assortment during meiosis, an almost unlimited genetic diversity is possible, which explains why sexually reproducing organisms can be so diverse.

What is recombination?

~ Recombination is the joining of two sets of chromosomes from two parents during sexual reproduction. This creates combinations of genes that are totally new, and have never occurred before. When this is considered along with independent assortment and crossing over, the number of genetic combinations for human beings is almost without limit.