LESSON 4: MEIOSIS

• gametes - sex cells
• meiosis - formation of gametes in males and females
• testis and ovary - where meiosis occurs; produce gametes
• During meiosis, one cell undergoes two consecutive cell divisions to produce four daughter cells, each having half as many chromosomes as the parent cell.
• two divisions of meiosis

  1. meiosis I
  2. meiosis II
• Before meiosis begins, all the chromosomes are duplicated.
• early prophase I - at the beginning of meiosis, each of the 46 chromosomes consists of 2 chromatids connected by a centromere
• middle prophase I

  • synapsis - chromosomes align as pairs
  • the pairing of the chromosomes brings 2 chromatids of each chromosome close together