Cell Division growing bigger

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Cell Division growing bigger!

• Also called Cell Reproduction!

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Why do cells divide?

• New cells for growth. You as 1 cell (ew!) and
  now trillions!
• New cells for repair / replacement liver donors,
  cat scratches, broken bones
• RBC!! WBC!! Go go go!

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Sex. Or not?

• Asexual reproduction in cells leads to identical
  daughter cells
• EX your skin, bacteria, paramecium, amoeba
• Sexual reproduction in cells leads to new genetic
  combinations. Like you! (EW!!)
• EX how sperm and eggs get together (EW!)

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Binary Fission what bacteria do in you!

http//www.emc.maricopa.edu/faculty/farabee/biobk/
BioBookmito.html
PROKARYOTIC CELL DIVISION (recall no nucleus!)
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• Chromosome yours look like this
• ONLY visible during cell division.
• What you see is a replicated chromosome.
• Each side is a chromatid.
• Sister chromatids are identical.

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Sister chromatids

• Held together by the centromere!
• DNA and proteins!
• Super condensed for division.
• Histones
• Nucleosomes

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How are chromosomes condensed for proper division?

HISTONES protein spools like a yo-yo DNA is
wrapped around histones like the string on a yo
yo NUCLEOSOMES coiled up DNA and protein unit
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In your cells DIPLOID

• You have 2 copies of each chromosome
• 46 total
• 23 from mom
• 23 from dad
• 22 pairs are autosomes
• 1 pair are sex chromsomes determine gender
• XX you are a gal, XY you are a guy

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karyotyping

• Play a matching game.homologues are paired up
  can see some genetic abnormalities

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Karyotyping 2
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Diploid buddies!

• Homologous chromosomes
• Homosame
• Same type of info but not exact info
• Again, one from mom, one from dad pair
• EX moms chromosome says HHT,
• dads chromosomes says no HHT

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Haploid sperm and egg

• 23 total chromsomes no buddies here!
• Half the normal diploid number
• N versus 2 n
• Just like math n n 2 n
• (more on meiosis later..)
• Gametes (sex cells) are haploid!

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The cell cycle!

• I interphase like intermission in a play
• P prophase PRO before
• M metaphase M middle
• A anaphase
• T telophase
• C cytokinesis CYTO cytoplasm

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The Cell Cycle or cell clock