Download Cell Division

Mitosis and Meiosis
Root Words
What is cell division?
Cells divide to grow, so they make copies
of themselves.
Chromosomes
 Bundles of genetic information made up
of DNA
Trisomy 21
Trisomy 21
Trisomy 18
Trisomy 18
Mitosis
 The process by which cells divide and
makes copies of itself
 Four stages:
 IPMAT
 Interphase, Prophase, Metaphase,
Anaphase, Telephase
Mitosis
 Is needed for new:
 Skin cells, hair cells, repairing cuts and
injuries
Cytokinesis
 It physically splits one cell into two by
“squeezing” the membrane
 Diploid- 2 sets of chromosomes (2n)
 1 from mom, 1 from dad
 Haploid- 1 set of chromosomes (n)
 Zygote: Fertilized egg
 Gamete: Reproductive cell (sex cell) that
contains the haploid set (n)
 Sperm or egg
Meiosis
 Division of Sex cells.
 Reason for genetic diversity
 2 Stages:
 Meiosis 1: IPMAT l
 Meiosis 2: IPMAT ll
Meiosis 1
 Same as
Mitosis
 Start with
1 Diploid cell
Meiosis 2
 End with
4 Haploid
daughter cells
 One of those
becomes a
sperm or egg.
 Homologous: Two sets of chromosome,
one from male and one from female.
 Crossing Over: A process occurring
during meiosis where
two chromosomes pair up and exchange
segments of theirgenetic material.
Haploid
Gamete (Female)
Gamete (Male)
Meiosis
Fertilization
Organism
Zygote
Mitosis
Diploid
Why Genetic Diversity?
Genetic Diversity
Crossing Over
 Chromosomes wrap
around tightly and
exchange DNA
 Results in Genetic
Diversity