BIOL 1201 Chapter : 3 13 12
Document Summary
Mitosis: produces daughter cells with the 2n chromosome number. In specialized tissues: cell divisions for gamete production, produces cells with 1n chromosome number, two divisions, meiosis 1 separates homologous chromosomes, meiosis 2 separates sister chromatids. Asexual reproduction: mitotic division: identical to the parent cell. Sexual reproduction: fuse gametes from parents (syngamy) to produce a zygote, each parent contributes half the genetic material. Stages of meiosis: prophase 1, metaphase 1, anaphase 1, telophase 1, prophase 2, metaphase 2, anaphase 2, telophase 2. Interphase: as in mitosis, during s phase dna is replicated, giving rise to chromosomes consisting of 2 sister chromatids. Crossing over: called chiasma (chiasmata-plural, hold homologous chromosomes together, can result in a physical exchange of genetic material between homologs, recombinant chromosomes result. Metaphase 1: chromosomes pairs align on the equator of spindle, kinetochores of sister chromatids are attaches to fibers going to the same pole. Anaphase 1: homologous chromosomes pairs separate, sister chromatids remain together.