Download Cell Cycle

Asexual Reproduction
presents:
Mrs. Stewart
Honors Biology: Cell Growth and Division
1
1
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BELL WORK
How do little elephants grow up to be BIG
elephants?
BELL WORK
Are the cells of the adult elephant larger
than those of the baby?
 CLE
3210.4.2
Describe the relationships
among genes, chromosomes, proteins, and
hereditary traits.
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Evaluate
the reasons for asexual
reproduction in organisms
Differentiate
between the different
stages of the cell cycle in terms of
order of occurrence, and
chromosome location
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 What
do they look like?
They look like an “X” just
before the cell divides and an
“I” after they divide.
 How
many do humans have?
• 46 (23 pairs)
•(23 from mom, 23 from dad)
There are two different types of cell
division
Which type is performed depends on the
kind of “daughter cells” that are desired

Mitosis = identical
daughter cells with
same amount of DNA

Meiosis = genetically
different daughter
cells with half the
amount of DNA
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Somatic Cells
Every cell in the body EXCEPT
reproductive cells
Have all 46 chromosomes
Gamete
Sexual reproduction cells
(Example: sperm for males,
Ova/eggs for females)
 have half the amount DNA (23
chromosomes)
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Somatic
OR
Gametes
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THINK – PAIR - SHARE
Why do animals shed their skin?
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THINK – PAIR - SHARE
How does a cut heal?
Three
reasons why cells reproduce
by asexual reproduction:
1. Growth
2. Repair
3. Replacement
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At what point does it
become necessary for a
cell to divide?
When the cells resources are under
too great a strain from it’s size
• Cell Membrane not large enough to maintain needs
coming in/going out
• DNA, used for protein synthesis, cant keep up with
demands
• Organelles unable to keep up with demands (ie:
waste removal)
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Which
phase does
the cell
spend the
most time
in?
Interphase
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CELL CYCLE
INTERPHASE
ANAPHASE
PROPHASE
TELOPHASE
METAPHASE
CYTOKINESIS
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Create
a mnemonic device to
help you remember –
I-P-M-A-T-C
We
will vote on the best one
tomorrow in class. Winner gets
a two day “slack” pass.
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 Mitosis
 Cell
animation – mcgraw-hill
cycle animation – cells alive website
 Mitosis
– sumanas (step by step w/ tutorial
and quiz)
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•Time between cell divisions
•90% of a cell’s life
3 phases:
1. G1: Growth and everyday
activities
2. S: DNA replication
3. G2: preparation for Mitosis
(production of necessary
proteins/organelles)
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Mitosis
The process of dividing
the nucleus to create two
daughter cells, identical
to the mother cell
Mitosis
• Creates two daughter cells that are
identical to each other AND
identical to the parent cell
• Creates diploid cells (two sets of
chromosomes in each daughter
cell)
• Allows organisms to grow
• Allows organisms to replace
damaged/worn out cells
• P-M-A-T-C
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•The DNA (chromatin) organizes
into chromosomes
•The nuclear membrane
disappears
•Centrosomes (centrioles) move
to opposite ends of cell
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Chromosomes attach to spindle
fibers (by their centromeres), and
line up at the center of the cell
Spindle Fibers –
microtubules that help
separate
chromosomes during
division
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Chromosomes
separate at the
centromere, and the
sister chromatids are
pulled toward opposite
ends of the cell.
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Chromosomes
disorganize and
the nuclear
membrane
begins to reform.
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The division of the cell cytoplasm, usually
beginning during Telophase and finalizing
the production of two new daughter cells.
Each new cell will have about ½ of the
cytoplasm and organelles of the parent
cell.
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CLEAVAGE FURROW
VS.
CELL PLATE
ANIMAL
Plants
Cleavage furrow
indentation of the
cell membrane to
form two separate
cells
Cell plate
A cell wall is rigid and cannot
flexibly move and pinch together
to separate the newly formed
cells. So, a cell plate forms
between the two new cells. This
cell plate will harden and become
a cell wall for each.
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Interphase
Prophase
Metaphase
Anaphase
I PMATC
Telophase
Cytokinesis
I
PLAY MUSIC AT THE CLUB
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Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
Animal Mitosis -- Review
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
Plant Mitosis -- Review
Interphase
Reflection:
Y
Identify the following:
• Structure X
• Structure Y
Which stage of the cell cycle is shown?
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