Crossing-over is a genetic phenomenon that occurs during meiosis and contributes to genetic mixing during reproduction (genetic recombination).
At the end of prophase 1 (early metaphase 1) of meiosis, the homologous chromosomes (i.e. of the same pair) overlap thus forming characteristic features called "chromatid tetrads" and exchange fragments of chromatids. The result is the intra-chromosomal mixing of the alleles
<span>During meiosis, genetic recombination may occur more than once through the process of ____________________, resulting in an increase in genetic variability.
A genetic bottleneck also known as a population bottleneck is one that describes a sharp reduction in the size of a population caused by environmental events like in the above or caused by human activities.
