By: Crash Course Biology

Hank gets down to the nitty gritty about meiosis, the special type of cell division that is necessary for sexual reproduction in eukaryotic organisms.

By: Bozeman Science

Paul Andersen explains how the process of meiosis produces variable gametes. He starts with a brief discussion of haploid and diploid cells. He compares and contrasts spermatogenesis and oogenesis. He explains how each person is different due to independent assortment, crossing over and random fertilization.

By: Bozeman Science

Paul Andersen describes mechanisms that increase the genetic variation within a population. He begins by discussing how horizontal transfer can move genetic material between bacteria. Transformation, transduction, and conjugation in bacteria are all included. He also explains how crossing over, random assortment, and random fertilization can maintain genetic variation i eukaryotes. He also explains how inbreeding can decrease the fitness of an individual.