Download 8. Mitosis Meiosis

8. Mitosis
Living Environment
Mr. Wiley
Overview of Mitosis
• Mitosis- cell division
• Cell Division- when one cell divides or splits into two new cells
• Asexual reproduction
• One “parent cell” becomes two “daughter cells”
• Cells are identical to the parent cell (same size, shape, DNA,
job)
• Occurs in somatic (body) cells
• Skin, eyes, muscles, organs, any cell that is not sperm/egg
I. Interphase
(PRE-Mitosis)
• Cell is preparing for
mitosis (division)
• DNA is duplicated
• Extra proteins and
organelles form
• Centrioles- proteins that
pull DNA apart
What does DNA
look like during
interphase?
II. M Phase
Two parts:
1. Mitosis “PMAT”
2. Cytokinesis
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
Interphase
A. Prophase
Prophase
• Nucleus begins to disappear
• DNA condenses to form
Chromosomes
• Chromosome- compact form of DNA,
looks like an X
• Centrioles move to opposite
sides of the cell
• Spindle fibers start to
form
What do you see?
Compare how the nucleus looks.
Compare how the DNA looks.
Compare how the centrioles look.
Is there anything new?
Prophase in real cells under the microscope
Prophase
B. Metaphase
• Chromosomes line up in
the middle of the cell
Metaphase
• Spindle fibers stretch
out and attach to
chromosomes
*Remember Metaphase…
“M” for “Middle”
because chromosomes
line up in the middle
What do you see?
Check out the
chromosomes &
spindle fibers
Metaphase in real cells under the microscope
Metaphase
C. Anaphase
*Remember Anaphase…
“A” for “Away”
because chromosomes
are being pulled away
from each other
Anaphase
• Spindle fibers pull
chromosomes apart
towards opposite sides
of the cell
What is happening?
Check out the
chromosomes &
spindle fibers
Anaphase in real cells under the microscope
• Two nuclei are formed
• Spindle fibers disappear
• Cell membrane starts to pinch
E. Cytokinesis
What is happening?
Cytokinesis
• Cell membrane pinches in and
cell splits
• Chromosomes unwind
Telophase
What is happening?
What formed/disappeared?
Anaphase
D. Telophase
Telophase in real cells under the microscope
Thirty seconds
Get a partner and dry erase board
What is it?
a
What is it?
b
What is it?
c
What is it?
D
What is it?
e
HeLa Cells
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Line of cells used for research
Named after Henrietta Lacks
Cells were stolen during her cancer treatment
Dr. Gey was successful in getting cells to perform mitosis in test
tube (1951)
Dr. Gey did not profit from these cells but sent them out to other
researchers
HeLa cells have been sold since 1954
60,000 articles, 11,000 patents
Family did not find out about HeLa cells until 1970s
The family cannot afford health insurance/care and many are sick
In the 1980’s a court case ruled that a patient has no rights to
money made off of their cells.
What are your opinions on this matter?
The accompanying diagram represents a cell process.
Which statement regarding this process is correct?
(A)Cell B contains the same genetic information that cells A and C contain
(B)Cell C has DNA that is only 50% identical to cell B
(C)Cell A has DNA that is only 75% identical to cell B
(D)Cells A, B, and C contain completely different genetic information