Centromere and independent assortment occurs which is

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centromere and independent assortment occurs (which is random alignment of chromosomes)Anaphase 1: homologous chromosomes separate and move to opposite poles of cell and sister chromatids arestill together (centromere doesn’t split so two sister chromatids from each homologous pair moves to each poleof cell-chromosome number is reduced from 2n (diploid) to n (haploid)Telophase1:homologous chromosomes begin to uncoil-spindle fibres disappear-cytokinesis happens forming nucleur membrane around each group of homologous chromosomes, two cellsform (technically they’re haploid b/c they have 46 chromatids but 23 chromosomes)*No replication between Meiosis and Meiosis 2MEIOSIS 2 (similar to mitosis)Prophase 2: centrosomes duplicate, nuclear membrane disappears, spindle fibres formMetaphase 2: haploid number of chromosomes lie up at the equator and spindle fibres attach to kinetocores oncentromeres-2 chromosomes in each, 2 new haploid cellsAnaphase 2: sister chromatids pulled apart at centromers by spindle fibers (happening in both new haploid cells)-now starts to form 4 new haploid cells (each haploid cell has 2 sister chromatids forming one chromosome)Telephase 2: nuclear membrane forms around 4 new haploid cells each with half number of chromosomes fromthe parent cellsynapsisthe aligning of homologous chromosomes during prophase 1homologouschromosomeschromosomesthat contain thesame sequenceof genes asanotherchromosome
What creates genetic diversity?Prophase 1-crossing over andMetaphase 1-independentassortmentOogenesis: the process of producing female gametes (eggs) in mammals and starts with ovam (femalegamete, plural ova)Oogonia reproduce by mitosis after birth, begin meiosis 1 but stop at prophase 1, and at puberty meiosis1 will continue to release one cell each monthProcess:-Start with diploid oogonium (oogonia) undergo mitosis before birth-Remaining oogonia that don’t die undergo meiosis and become primary oocytes-Primary oocytes pause during prophase 1 after replicating but before meiois 1 they stay rested until theirmenstrual cycles begin-When girl hit puberty p.o resume meiois from where they left off and finish meiois 1, (they stop at metaphase 2unless they are fertilized) then divides chromosomes equally but there is unequal division of cytoplasm-At cytokinesis almost all cytoplasm remains in one of the two daughter cells which becomes the secondaryoocyte-The other daughter cell with half the chromosomes but little cytoplasm is called polar body and since its notfunctional it’ll eventually degenerate and die-S.o (has 2 copies of each chromosome) and become a fully functional ovum must undergo meosis 2 anddivision in uneven again (where half chromosome going to small degenerate polar bear)-The other half is gone to the ovum (half chromosome and almost all of cytoplasm) creating an egg
Spermatogenesis: the process of producing male gametes (sperm) in mammals-doesn’t start until pubertyProcess:-Starts with diploid cell called spermatogonium (plural spermatogonia)

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Term
Fall
Professor
na
Tags
DNA, Mitosis, Gamete

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