biological purpose of sexual reproduction
reproduce the genetic material of the organism
independent assortment of chromosomes
chromosomes can line up so that the replicated which were formed during meiosis can get multiple allele configurations.
Ex: 4 chromosomes, 2 homologous pairs replicate. one from each pair has either recessive or dominant alleles. end up with either RR, DD or both hetero
you get different combinations of traits from the father or mother.
you have a random chance that a particular sperm with particular traits is going to fertilize a particular egg with a particular trait.
In other words, hard to get exact same genes twice
chromosomes group in homologous pairs and crossing over begins
homologous chromosomes are arranged on the metaphase plate with one chromosome in each pair facing each pole
the fusion of two gametes.