1. Meiosis vocabulary Sperm- male sex gamete ( 1N)
Egg- female sex gamete (1N)
Haploid –cell containing one of each kind of chromosome (1 N)
Diploid - cell containing two of each kind of chromosome ( 2N)
Homologous Chromosomes- paired chromosomes with genes for the same traits arranged in the same order
Meiosis –type of cell division where one cell produces four gametes, each containing half the number of chromosomes in the parent’s body cell.

2. Sexual vs. Asexual reproduction
Sexual reproduction- type of reproduction that requires the production of the fusion of two parent (haploid) sex cells.
Ex. Humans, dogs, most plants
Zygote - a fertilized egg
Asexual reproduction- reproduction involving only one parent cell.
Ex. Yeast/ budding & bacteria/ binary fission

3. Problems with Meiosis…
Non- disjunction- failure of homologous chromosomes to separate properly during meiosis- results in too many or two few chromosomes---- PROBLEMS!
-- organisms with too few chromosomes often die while those with extra chromosomes often survive
ex. Trisomy 21 ( an extra #21 chromosome is Down’s syndrome)
Crossing over- exchange of genetic material between nonsister chromatids from homologous chromosomes during Prophase 1  results in new allele combinations

4. Meiosis- purpose is for reproduction and to increase genetic variation!
Cell reproduces chromosomes and then essentially divides twice producing 4 sex cells each with half the chromosomes
4 sperm and 1 egg + 3 oocytes that eventually die off
( think about it)
Two stages– Meiosis 1 and Meiosis 2
Interphase Prophase 1 Metaphase 1 Anaphase 1 Telophase 1
Interkinesis– ( break time)
Prophase 2 Metaphase 2 Anaphase 2 and Telophase 2
Cytokinesis