Mitosis and Meiosis - " Growth VS Sex "

" During Meiosis - Women put all of their "eggs" into " one basket ", whereas men use the " shotgun approach " for sperm "

Chromatin - diffuse DNA in the nucleus

          Histone - Proteins that DNA is wound around to make chromosomes

Chromosome - 1 strand of DNA that has been coiled and condensed

Mitosis - Division of the nucleus - used for growth and repair

Cytokinesis - Division of the cytoplasm

Cell Cycle - Entire cycle of growth, preparation for division and finally division

          Interphase - Time after cytokinesis and before mitosis. DNA duplicates

*Prophase - First time chromosomes become visible - centrioles move to opposite poles - nuclear membrane dissappears

Chromatid - A single strand of DNA

          Sister chromatid - 2 identical copies of a strand of DNA

                    Centromere - Binds 2 identical sister chromitids together

Centrioles - Are chromosome organizers (move chromosomes with fibers) - move to opposite poles

*Metaphase - All sister chromitids line up at the midline of the cell

*Anaphase - The 2 identical sister chromotids separate and move to opposite poles

*Telophase - Chromosomes become diffuse again - new nuclear membrane forms

Gametogenesis   (Meiosis) - Used to make gametes that have half the number of chromosomes

          Gametes - Sex cells - sperm or egg

                    Haploid   (N) - 1/2 the chromosome number

Zygote   (2N) - Has 23 pairs of homologous chromosomes 46 total

          Diploid   (2N) - A full set of 46 chromosomes

Meiosis 1 - Homologous chrosomes split in anaphase

          Homologous chromosomes - 2 chromosomes that have the same genes - 1 from father and 1 from mother

Meiosis 2 - Sister chromatids split in anaphase

Polar body - Formed during meiosis in females where eggs get no cytoplasm (or organelles) and die

Return to Greg Sievert's GB 100 Syllabus
Last updated on 4 January 2018