Meiosis 10/29/09 Slide 2 What can you tell me about Mitosis?
Slide 3 Lets Review! Interphase Prophase Metaphase Anaphase
Telophase & Cytokinesis Slide 4 Go to animation Slide 5 Two
main cell types in your body! 1. Diploid Somatic cells (body cells)
Have 23 pairs of homologous chromosomes 2. Haploid Reproductive
(sex) cells Sperm and egg cells Also called gametes Only contain 23
chromosomes (not paired!!) Slide 6 Meiosis Meiosis is the type of
cell division by which gametes (eggs and sperm) are produced. One
parent cell produces four daughter cells. During meiosis, DNA
replicates once, but the nucleus divides twice. Slide 7 Meiosis I 1
st division of meiosis Slide 8 Prophase 1: Each chromosome
duplicates and remains closely associated. These are called sister
chromatids. Crossing over portions of the sister chromatids
exchange spots. Slide 9 Crossover a. The process by which two
chromosomes pair up and exchange sections of their DNA. Each
chromosome is from one parent b. This process leads to offspring
having different combinations of genes from their parents Slide 10
Metaphase I Chromosomes align at the center of the cell. Slide 11
Anaphase 1: Chromosome pairs separate with sister chromatids
remaining together. Slide 12 Telophase I Two daughter cells are
formed with each daughter containing only one chromosome of the
chromosome pair. Slide 13 Meiosis II 2 nd Stage of meiosis Slide 14
Prophase 2: DNA does not replicate. Slide 15 Metaphase 2:
Chromosomes line up at the center of the cell Slide 16 Anaphase 2:
Centromeres divide and sister chromatids move separately to each
pole. Slide 17 Telophase 2: Cell division is complete. Four haploid
daughter cells are formed Slide 18 Slide 19 Slide 20 Go to
animation Slide 21 Meiosis Slide 22 Differences in Mitosis &
Meiosis Mitosis Asexual Cell divides once Two diploid daughter
cells Genetic information is identical Makes somatic cells body
cells 2n Meiosis Sexual Cell divides twice Four haploid daughter
cells Genetic information is different Makes gametes sex cells
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