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MITOSIS
Think About This…
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What is this?
What IS cancer?? What are some causes?
What are some reasons for cell division?
How do you think a cell would accomplish
this task?
SO WHY LEARN ABOUT CELL
DIVISION??
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Growth
Cancer- uncontrolled growth
Cells have given life spans; need to
replace!
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Lining of esophagus 2-3 days
Lining of small intestine 1-2 days
Skin 2-4 weeks
Stem Cells
All Cells Come From Cells
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One concept of the cell theory we just
learned about!
All organisms reproduce their own kind…
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Asexual Reproduction
Sexual Reproduction
Types of Cell Division We Will Learn
About
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Mitosis- Division of somatic cells (body
cells)
Meiosis- Creation of gametes (sex cells)
Lab- You Are a 19th Century Cell
Biologist
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In this lab, you will assume the role of a biologist
in the mid-1890s. You are fascinated by the
power of the microscope to reveal the inner
workings of living cells. The invention of the
compound microscope, along with new stains,
make it possible for you to see cell structures
that no one has ever seen before. You plan to
collaborate with your colleagues to discover the
events of cell division.
Lab- You Are a 19th Century Cell
Biologist
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Things you know right now:
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1) The cell has many organelles.
2) The nucleus seems to be pretty important.
3) There seem to be “structures” inside the
nucleus that undergo changes during cell division
(chromosomes).
Lab- You Are a 19th Century Cell
Biologist
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1) Obtain a microscope and a slide of onion
root tip.
2) Focus under low power.
MITOSIS-ONION ROOT TIP
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3) Move to high power; only adjust here
with the fine focus.
Lab- You Are a 19th Century Cell
Biologist
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4) Select one cell whose chromosomes are
clearly visible & sketch in the box.
5) Look around and select 4 other cells whose
internal appearances are different and sketch
them as well.
6) Try and place your sketches in order from 15.
7) Check your answers with Mrs. Romano…
how many did you get right??
Lab- You Are a 19th Century Cell
Biologist
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8) Identify the phases of cell division.
9) Count the number of cells in your slide in
each stage of cell division.
10) Answer the analysis questions.
MITOSIS
Review- Cell Parts
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TERMS TO KNOW:
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Nucleus
Nuclear envelope
Centriole
Spindle Fiber
Chromatin
Chromatid
Chromosome
Centromere
Chromatin vs. Chromosomes
Do All Cells Divide??
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NO!!
Muscles, neurons, red blood cells, white
blood cells generally DO NOT go through
mitosis.
Cell Cycle
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Orderly sequence of
cell division
INTERPHASE- Cell
grows, DNA replicates,
gets ready to divide;
LONG
MITOSIS (cell divides)
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4 parts
Chromosome duplication
MITOSIS- Step 1 of 4
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Prophase- chromosomes condense,
nuclear membrane disappears, spindle
forms
MITOSIS- Step 2 of 4
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Metaphase- chromosomes move to center
of the cell and attach to spindle fibers
MITOSIS- Step 3 of 4
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Anaphase- Chromosome strands move
towards opposite ends
MIATOSIS- Step 4 of 4
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Telophase- Chromosomes reach ends;
nuclear envelope reforms; cytoplasm
divides (CYTOKINESIS)
Plant vs. Animal Cell Mitosis
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ANIMALS- cleavage
furrow
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PLANTS- cell plate
Stages in an onion root tip
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Movie
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Mitosis Video
Review- Mitosis
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Animation
Mitosis Movie!!
Cancer
 Out-of-control
cell reproduction
 TUMOR- mass
of cells
 Benign
 Malignant
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Breast Cancer cells
Metastasis
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Most dangerous property of cancer cells is
their ability to spread beyond their original
site
Detection
Detection
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Visual
Radiation Imaging (spot glows under UV
light)
Biological or chemical test (spot changes
color when exposed to a chemical)
Treatment
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Radiation Therapy
Chemotherapy
Causes
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Getting older
Genetics
Tobacco
UV radiation (sunlight)
X-rays
Certain chemicals
(asbestos, vinyl
chloride, nickel)
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Certain viruses/
bacteria (HPV,
Hepatitis C, HIV)
Certain hormones
(excess estrogen)
Alcohol
Poor diet/ lack of
exercise
Melanoma- One Type of Skin Cancer
Breast Cancer
Lung Cancer
Prostate Cancer
Leukemia
Colon Cancer
Video
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The Genetics of Cancer