1. Presenting…
Meiosis

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Why is meiosis important?
• It makes sexual reproduction possible. P.324
• Results in a new individual that has a unique
combination of genes.Pg. 613
• Each parent gives exactly one-half of the chromosomes.
• Making a full set of chromosomes for its species.

3. Meiosis
i = how i was created!
• Two nuclear divisions
• Produce or make:
1. Sex cells (sperm and
egg)
2. The sex cells have half
of the chromosomes of
the parent cell -23
3. This happens to make
cells for sexual
reproduction (Oh my!)

4. • Sex Cell
• Egg or sperm
• Sex Chromosome
• Thread-like
chromosome that
carries the genes
that determine the
sex of the offspring.
• XX=girl
• XY=boy

5. Meiosis Animation
• http://www.biology.arizona.edu/cell_bio/tut
orials/meiosis/page3.html

6. Comparison
Mitosis and Meiosis
• Mitosis
• Meiosis
• (My toe, sis!)
• Makes body cells.
• New cells have the same
number of
chromosomes as the
original cell. IDENTICAL
• (i was made this way!!)
• Makes sex cells.
• New cells have half of
the number of
chromosomes as the
original.
• New cells are identical
to the original cell
• No two sperm or egg
cells are ever exactly
alike.
•
Meaning:
Skin cells make skin cells,
bone cells make bone cells,
etc.
• Offspring or babies will be
unique!