Mitosis/Meiosis “Cheat” Sheet

advertisement
Mitosis/Meiosis “Cheat” Sheet
Mitosis




For repair of damaged cells and growth of the organism
Mitosis occurs most in the cells in organs (such as the skin, stomach) that get
the most wear
Produces 2 genetically identical cells
The cells have 2 full sets of chromosomes

One set came from each parent – this is the number of chromosomes in
all somatic cells (body cells)




Therefore the cells are diploid
The cell goes through 1 cycle of the 5 phases of mitosis

Prophase – where DNA is uncoiled

Metaphase – where the chromosomes line up in the center of the cell

Anaphase- where the chromosomes start to separate

Telophase – where the two cells begin to separate

Cytokinesis - where the two cells complete their separation and begin
to grow
During S phase of the cell cycle (but not a part of mitosis) the DNA is replicated
During interphase (also, not part of mitosis) the cell is performing its function for
the organs –

Cells spend most of their time in interphase
Meiosis



For production of gametes, the sex cells, sperm and egg
Meiosis produces 4 cells that are genetically different
Each gamete has only 1 set of chromosomes

During fertilization, the egg and sperm join and create a zygote that has
the full 2 sets of chromosomes


The gametes are haploid
The cell goes through 2 cycles of the 5 phases of mitosis

In Prophase I small pieces of DNA may cross over from one
chromosome to the other – this is called crossing-over

During crossing-over, there is increased genetic recombination

Throughout the first cycle (Metaphase I – Cytokinesis I) the duplicated
chromosomes remain connected.

Prohpase II through Cytokinesis II are very similar to these phases of
mitosis, except there is no duplication of the DNA – only cell division
MITOSIS
MEIOSIS
Download