The Importance of Mitosis

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The Importance of Mitosis
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The need to heal!
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The need to grow!
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DNA

• Made of nucleotides
• Phosphate
• sugar
• Nitrogen base
• Adenine
• Guanine
• Cytosine
• thymine

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Coiling

• Uncoiled DNA called chromatin- between cell
  divisions
• Happens during cell division
• DNA wraps tightly around proteins called histones

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Chromosomes

• Chromosome- consists of two identical halves
  connected together by a cnetromere
• Chromatid- a half of one chromosome.
• Contains one complete set of information
• Copies itself to make the other chromatid

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How many chromosomes??

• Each human diploid cell is 2N and contains 46
  total
• 23 identical pairs
• ( 23 x 2 46 ) homologous chromosomes
• carry the same traits

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How many chromosomes??

• Egg and sperm cells only carry one set of 23
• Each human haploid cell is N
• Egg and sperm combine to form 2N or 46
• All other chromosomes are called autosomes
• Each human or animal cell has sex chromosomes XX
  or XY
• Define the sex of the organism

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Cell Cycle

• G1 cell grows
• S DNA replication
• G2 Prepare to divide
• M Mitosis

INTERPHASE
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2-4-8-16, etc
Quicktime video
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Stages of Mitosis

• Prophase
• Metaphase
• Anaphase
• Telophase
• Cytokinesis

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Birth of a Brain Cell

• Quicktime movie

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TWO REASONS FOR MITOSIS

• Healing/Repair
• Growth
• THE NEXT SLIDES ARE GRAPHIC

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REASON FOR MITOSIS
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Let the healing begin
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• Better

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Much better
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Mitosis in onion root tip

• Why onion root tip?
• Actively growing, lots of cells dividing
  (mitosis)
• Where exactly should you look on the microscope
  slide?

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Cell division differences in plant vs animal cells

• Which is the animal cell and which is plant?
• Which stage of mitosis is being shown?

CLEAVAGE FURROW
CELL PLATE
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Stages of mitosis id slide 1
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2 and 3
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4 and 5
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6 and 7
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8 and 9
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10, 11, 12
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13, 14, 15
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16, 17, 18
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• YOUR QUIZ ON MITOSIS IS TOM.
• Heres what you need to be able to do