Download Meiosis = nuclear division that reduces chromosome

Meiosis = nuclear division that reduces chromosome number by half
 sex cell division
 gametes = sperm & egg (ovum) (plural = ova)
 results in 4 haploid cells
 sperm (23) + egg (23)  zygote (46) = fertilized egg
 you have exactly ½ of your Dad’s chromosomes and ½ of your Mom’s
 puberty = stage in life when sex cells begin to develop
Two Stages of Meiosis:
Meiosis I (preceded by DNA replication) = homologous chromosomes separate
Meiosis II = sister chromatids separate
Tetrad (tetra- = 4) = pair of homologous chromosomes
 sketch on whiteboard
Synapsis = pairing of homologous chromosomes
 occurs in prophase I
 does not occur in mitosis
Crossing Over = portions of chromatids break off & attach to adjacent chromatids on the
homologous chromosome (results in genetic diversity)