BIOL 120 1st Edition Lecture 16Outline of Last LectureI. Other types of photosynthesis II. Meiosis OverviewOutline of Current LectureI. Overview of MeiosisII. Mitosis vs. MeiosisIII. Crossing OverIV. Results of MeiosisV. Mendel’s Experiment Current LectureI. Overview of MeiosisA. Meiosis reduces chromosome number by half  diploid to haploid B. Consist of two cell divisions: Meiosis I and Meiosis II 1. Meiosis I  diploid parent cell produces two daughter cellsa). homologs in each chromosomes pair separate and go to different daughter cell b). haploid daughter cells still have chromosome of two identical sister chromatid 2. No replication after Meiosis I 3. Meiosis II  sister chromatid of each chromosome separate and go to different daughter cells a). similar to mitosis These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.b). produces 4 haploid daughter cells  called gametes through the process of gametogenesis C. Fertilization of gametes1. results in a zygote  a fertilized cell containing a full complement of chromosomes (diploid) 2. receives a haploid chromosome set from both mother and father D. Meiosis Division1. Interphase  DNA replication2. Meiosis I  separation of homologous chromosomes a). Prophase Ib). Metaphase Ic). Anaphase Id). Telophase I3. Meiosis IIa). Prophase IIb). Metaphase IIc). Anaphase IId). Telophase II4. Cytokinesis II. Mitosis vs. MeiosisA. Mitosis  creates identical diploid daughter cells B. Meiosis  creates non identical haploid daughter cellsIII. Crossing OverA. at the point where chromosomes cross over the non-sister chromatid from each homolog physically break at the same point and attach to each other  maternal and paternal chromosomes are swapped B. Occurs in Prophase IC. results in recombinant chromosomes IV. Results of MeiosisA. four gametes with a chromosome composition different from parent cells B. Sexual reproduction creates great genetic variety C. Separation and distribution of homologous chromosomes during meiosis I creates variety  giving each daughter cell a great deal of genetic diversity 1. humans can produce 8.4 million different combinations of chromosomes in gametesV. Mendel’s Experiment A. Gregor Mendel  19th century monk interested in heredity (transmission of traits from parents to offspring)1. understood that all traits have 2 possible alleles  1 from mom and 1 from dada). matching alleles  homozygousb). different alleles  heterozygous2. Genetics  branch of biology that focuses on the inheritance of traits B. used peas (model organisms) for his experiment 1. preventing the plants from self –fertilization and pollinated them by hand to control cross pollination 2. Study: seed shape, seed color, pod shape, pod color, flower color, flower and pod position, and stem length a). phenotype  observable features b). purelines  identical offspring from self pollinated c). hybrids  created by mating two different pure lines that differed in one or more