MeiosisWhat does this picture tell us about meiosis?How is the purpose of meiosis different from the purpose of mitosis?

Why is meiosis necessary?Why cant mitosis be the cell division process that runs sexual reproduction?What would happen to the chromosome number from one generation to the next?46 921843687361472

In sexual reproduction, meiosis and fertilization are complementary processes; Meiosis produces the haploid chromosome number (n) andFertilization restores the diploid (2n) chromosome number in the zygote.Meiosis is often called Reduction Division since the process reduces the number of chromosomes in half (2n n)(Mitosis would be 2n 2n or n n)

Meiosis involves two divisionsEach division includes prophase, metaphase, anaphase, and telophase.A Roman Numeral is added to each phase.Prophase I Metaphase I Anaphase I Telophase I Interphase (no DNA replication) Prophase II Metaphase II Anaphase II Telophase II

Stage Descriptions/CharacteristicsProphase ISynapsis occurs Homologous chromosomes pair upEach group is made up of 4 chromatids.Each group of 4 chromatids is called a TETRAD.

Crossing OverWhen parts of non-sister chromatids change places(increases genetic variety)

Metaphase IThe tetrads are aligned at the equator.[note the crossing over]

Anaphase ITetrads split and chromosomes (in replicated form) move to opposite poles.

Telophase ITwo cells form each cell is haploid but each chromosome is in replicated form.

Interphase(INterkinesis)DNA is in chromatin form.No DNA replication occurs! Why? because each cell contains chromosomes already in replicated form no need to copy

Prophase IIEach cell is haploid with chromosomes in replicated form. note the Crossing over

Metaphase IIChromosomes align at the equator in both cells.

Anaphase IIChromosomes separate Chromatids move towards opposite poles.(Centromeres split.)

Telophase II4 cells result each cell is haploid with unreplicated chromosomes.Each cell will become a gamete (sperm/egg)

What phase of meiosis?

Telophase I or Telophase II?

Meiosis I or II just like Mitosis?