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Cards In This Set
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Diploid somatic (body) cells produce more diploid somatic cells; daughter cells are identical to parent cells.
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Mitosis
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1. Function: growth and repair; asexal reproduction.
2. Number of division series: one
3. Result: two diploid (2n) cells.
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Mitosis
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Diploid germ cells produce haploid sex cells (gametes); daughter cells are gentically unique.
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Meiosis
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1. Function: sexual reproduction
2. Number of division series: Two
a. Meiosis I - Reduces chromosome number by half
b. Meiosis II - Multiplies the cell number (just like mitosis)
3. Result: Four haploid (n) cells
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Meiosis
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1. Synapsis: Homologous chromosomes pair up and align point by point.
2. Crossing Over: the process occuring during synapsis, in which homologous chromosomes exchange segments of chromosomes; results in new combos of genes in each chromosome and is one source of genetic variation.
stage of meiosis
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Prophase I
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Homologous chromosomes randomly line up at the spindle equator in a process known as "random assortment"; this is another source of genetic vartiaion.
stage of meiosis
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Metaphas I
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Homologous chromosomes (still duplicated) seperate (more to opposite poles) forming two haploid cells each of which has a random mix of maternal and paternal chromosomes (known as "random assortment")
stage of meiosis
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Anaphas I
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Results in two haplod cells; no interphase or DNA replication.
stage of meiosis
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Telophase I
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Chromosomes recondense.
stage of meiosis
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Prophase II
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Individual chromosomes line up at the equator.
stage of meiosis
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Metaphase II
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The chromatids seperate and are renamed "daughter" chromosomes.
stage of meiosis
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Anaphase II
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Results in four haploid cells.
stage of meiosis
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Telophase II
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Sources of genetic variability:
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-Synapsis and crossing over in prophase I
-Random assortment at metaphase I (leads to millions of combos of maternal and paternal chromosomes in each gamete)
-Fertilization: of all the gentically diverse gametes produced, chance will determine which two will meet.
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Gamete formation
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Gametogenesis
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Meiosis and gamete formation in males.
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Spermatogenesis
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