01:119:115 Lecture Notes - Lecture 22: Telophase, S Phase, Synapsis
25 Feb 2016
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Document Summary
Heredity; transmission of traits from one generation to the next (inheritance) Gametes; reproductive cells transmit genes form one generation to the next. Asexual reproduction; single parent produces offspring- no crossing. Fusion of 2 gametes to form a zygote. Gametes usually from diff parents (but not always) Better able to respond to change or strength. If gametes had same chromosome # as parent, chromosome # would double each generation. 1 diploid (2n) cell--> 4 haploid (n) cells. Sex chromosomes; x and y determine individuals sex. Small homologous region in x and y chromosomes. Life cycle; sequence of stages from generation to generation. Meiosis has 4 stages and involves 2 cell divisions. Each chromosome now 2 sister chromatids (still chromatin) First meiotic division- homologous chromosome separate ploidy reduced. Each meitoic division included the same stages of mitosis except prometaphase. First and second meiotic divisions are indicated in the name of the stage. Same as mitotic prophase with 1 giant difference; crossing over.
