IN Pg. 2

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IN Pg. 2 Use pg. 197 Biology Book.

• What is the difference between a hypotonic and a
  hypertonic solution?
• Answer in Blue, Black or Pencil

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Do it now Pg. 2N.12.B.2 http//www.rpdp.net/scien
cetips_v2/N12B2.htm

• The ecological resource consumption practices of
  the average citizen of the United States
• is less than all other parts of the world.
• is balanced by recycling plastic items.
• is greater than most countries in the world.
• contributes to sustainable living practices.    

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Do it now Pg. 2N.12.B.2 http//www.rpdp.net/scien
cetips_v2/N12B2.htm

• The ecological resource consumption practices of
  the average citizen of the United States
• is less than all other parts of the world.
• is balanced by recycling plastic items.
• is greater than most countries in the world.
• contributes to sustainable living practices.    

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Mitosis

• Notes Pg. 3

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What is the Cell Cycle?

• A period of time from the
• beginning of one cell division to the
• beginning of the next cell division.
• Divided into 4 phases
• (G1, S, G2, and M)

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G1 Phase
M Phase
S Phase
G2 Phase
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What happens in interphase?

• S Phase
• Chromosome replication
• DNA molecules duplicate

• G1 Phase
• Growth and activity
• Cell double in size
• Number of ribosomes and mitochondria double

• G2 Phase
• Final preparation for cell division
• Spindle fibers assemble

• Mitosis
• Actual cell division

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What is Mitosis?
Mitosis - is the process of nuclear division
in eukaryotic cells.
Before mitosis begins, the chromosomes in the
nucleus of each parent cell must replicate
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• Chromosome -
• has 2 coiled chromatids, joined at the centromere

• Chromatid -
• Single strand of a chromosome
• Found in identical pairs
• Called sister chromatids

• Centromere
• Part of the chromosome where the chromatids are
• attached

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Chromosome
Chromatid
Centromere
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Chromosome
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What are the 4 Phases of Mitosis?
Prophase Metaphase Anaphase Telophase
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 What areMitosis and Cytokinesis?
Spindle forming
Centrioles
Centromere
Chromatin
Centriole
Nuclear envelope
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Individual chromosomes
Telophase
Anaphase
Nuclear envelope reforming
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What is Prophase?

• Longest phase of mitosis (60)
• Chromosomes come together and form thick
• thread like structures
• Centrioles (animals cell only) separate
• Spindle fibers grow from the centrioles

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Prophase
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Prophase
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What is Metaphase?

• Shortest phase of mitosis
• Chromosomes are completely attached to
• spindle fibers
• Chromosomes line up in the center of the cell

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Metaphase
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Metaphase
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What is Anaphase?

• Centromeres holding the chromatids split
• Microtubules pull the chromatids apart
• Chromosomes are now at two separate ends
• of the cell

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Anaphase
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Anaphase
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What is Telophase?

• Spindle fiber begins to break apart
• Chromosomes at each end of the cell, start
• to spread out
• Nuclear membranes form around each
• cluster of chromosomes
• Two distinct nuclei are formed within the
• cell

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Telophase
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Telophase
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What is Cytokinesis?

• Cytoplasm and its contents divide into
• 2 daughter cells
• Each daughter cell receives 1 nucleus
• and half of the cytoplasm

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Cytokinesis
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2 Daughter Cells
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After cytokinesis, the daughter cells return to
interphase
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Mitosis (Onion Cell)
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Mitosis (Onion Cell)
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Cell Cycle and Cell Division Facts
Mouse Cell - completes the cell cycle in 22
hours Bean Cell - completes the cell cycle in 19
hours Adult Human - Around 2 trillion cell
divisions occur in a 24 hour period This 25
million cell division per second
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Do it now Pg. 2

• Accurate estimates of the age of Earth were not
  possible until what discovery was made?
• Earths molten core cools at predictable and
  measurable rates.
• Radioactive decay occurs in certain elements at a
  constant rate.
• The oldest fossils are found in layers at the
  bottom of rock strata.
• The shrinking diameter of the Sun can be used to
  infer the age of planets.

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Nature of ScienceN.12.B.4 http//www.rpdp.net/sci
encetips_v2/N12B4.htm

• Accurate estimates of the age of Earth were not
  possible until what discovery was made?
• Earths molten core cools at predictable and
  measurable rates.
• Radioactive decay occurs in certain elements at a
  constant rate.
• The oldest fossils are found in layers at the
  bottom of rock strata.
• The shrinking diameter of the Sun can be used to
  infer the age of planets.

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Out Pg. 2

• What is the longest phase of Mitosis and why does
  it take so long?
• Answer in blue, black or pencil.

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IN Pg. 4

• What are the phases of Mitosis in order?
• Answer in Blue, Black or Pencil

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Do it now Pg. 4

• Patricia A. Bolton suggests deliberate deceit
  and dishonesty, including forged or fabricated
  data, falsified or invented results, and
  plagiarism belongs within the category of
• honest mistakes.
• noncompliance.
• scientific misconduct.
• ethical behavior.