Meiosis

1
Meiosis
2
Meiosis

• Cell division that reduces the number of
  chromosomes by half
• 2 nuclear divisions
• Meiosis I
• Meiosis II

3
Meiosis I

• Homologous chromosomes separated into separate
  cells

4
Meiosis II

• Chromatids of each chromsomes are segregated into
  separate cells

5
Meiosis I
6
Prophase I
7
Prophase I
8
Prophase I

• DNA Coils
• Spindle Fibers appear
• Nuclear membrane and nucleolus disappear
• Chromsome lines up next to its homologue
• synapsis

9
Synapsis

• Pairing of homologous chromosomes
• Form a tetrad group of two chromosomes
• Crossing over occurs
• Exchange of genes between non-sister chromatids

10
Metaphase I
11
Metaphase I

• Tetrads move to center of cell

12
Anaphase I
13
Anaphase I

• Pairs of homologous chromosomes separate
• Each chromosome still made up of two chromatids
  connected by centromere

14
Telophase I
15
Telophase I

• Cytoplasm divides two daughter cells from
• Chromsome is halved but each has twice the
  amount of DNA

16
Meiosis II
17
Prophase II
18
Prophase II

• Plant cell Chromosomes coil again
• Animal cells still coiled
• New Spindle fibers form

19
Metaphase II
20
Metaphase II

• Chromosomes move to equator

21
Anaphase II
22
Anaphase II

• Centromere divides
• Each sister chromatid moves to opposite poles

23
Telophase II
24
Telophase II

• Spindle fibers disappear
• Nuclear membrane and nucleolus reappear
• Cytokinesis occurs resulting in two new daughter
  cells with half the original of chromosomes