EQ: How do the cells in your body reproduce? Mitosis and Meiosis EQ: How do the cells in your body reproduce?

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 Down’s Syndrome

Trisomy 21

Trisomy 18 Edward’s Syndrome

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) Haploid- 1 set of chromosomes (n) 1 from mom, 1 from dad Haploid- 1 set of chromosomes (n)

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.

Zygote: Fertilized egg Gamete: Reproductive cell (sex cell) that contains the haploid set (n) 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.

Why Genetic Diversity?

Crossing Over Chromosomes wrap around tightly and exchange DNA Results in Genetic Diversity

Comparison of Mitosis and Meiosis Mitosis occurs in all cells of the _____ except _____________. Meiosis only occurs in the formation of _____________. body egg and sperm egg and sperm

Comparison of Mitosis and Meiosis In meiosis, each _______ cell divides ______ to produce a total of ___ cells. In mitosis each _______ cell divides _____ to form ___ cells. diploid twice 4 diploid once 2

Comparison of Mitosis and Meiosis In meiosis, each of the four cells contains _____ the number of chromosomes as the parent cell. In mitosis, each new cell contains the ______ number of chromosomes as the original cell. half same

Comparison of Mitosis and Meiosis In mitosis, the homologous pairs do not come together to form _______. In meiosis, the homologous pairs do come together to form _______. While the chromosomes are in tetrads, _____________ may occur. There will be no crossing over in _______. tetrads tetrads crossing over mitosis

Comparison of Mitosis and Meiosis In meiosis, the four haploid cells contain ________ combinations of chromosomes from each other. In mitosis, the new cells contain ________ copies. different identical

LEFT SIDE ACTIVITY Draw the label the stages of Mitosis Draw and label the stages of Meiosis