PSY354H5 Lecture Notes - Lecture 11: Promiscuity, Egg Cell, Mitosis
Document Summary
However, recent research has found that there may have been sexual reproduction in their history: mitosis: cell division resulting in preserved chromosomal number, sexual reproduction, offspring inherit genes from two parents, mixing of genes from two gametes that are haploid cells (via meiosis, meiosis: cell division resulting in halved chromosomal number, figure (slide 6, sexual reproduction, within bacteria, similar process also happens. Why sexual reproduction: why not give birth parthenogenetically, figure (slide 8, asexual: same dna is passed on till the fourth generation, sexual: there is a secondary external source of dna that ges mixed; don"t know what genes will mix, two theories, provides a mechanism to cope with harmful mutations. Particularly advantageous in stressful situations: the red queen hypothesis (polymorphisms, proposes that organisms must constantly adapt, evolve, and proliferate not merely to gain reproductive advantage, but also simply to survive while pitted against ever evolving opposing organisms in an ever changing environment.
