Biology 1201A Chapter Notes - Chapter 9.1-9.3: Nuclear Membrane, Interphase, Sister Chromatids
Document Summary
Two daughter cells vs. four daughter cells. Most important difference is in synapsis phase. Physical exchange of sequences between chromatids of homologous chromosomes. Dna backbones are broken and free ends exchanged. One chromosomes from mother and one from father. All mitochondria inherited from the egg (maternal ) Paternal mitochondria not transmitted during fertilization ,or possibly destroyed. Once meiosis is completed without having a pair of homologous chromosomes separating , an extra chromosomes in final two of four cells. Result in down syndrome as the two chromosomes mix with one and create three chromosomes. The sugar -phosphate backbone is held together by strong covalent bonds, whereas the bases pairs with their partners is a weak hydrogen bond. Sexual reproduction, the production of offspring though the union of male and female gametes: the mixing of genetic information into new combinations and halving the chromosomes number, occurring through meiosis. Sexual reproduction depends on meiosis, a specialized process of cell division that recombines.