Transcript Animal Cell

Animal Cell
Plant Cell
The Difference Between Animal and Plant
Cells
•Plants have a rigid cell wall that lies outside the cell
membrane. The cell wall provides structure and
support for the plant cell
•Fungi and most bacteria also have a cell wall
•Multi-cellular plants rely on the strength of
their cell walls to support the entire organism
•Plant cells contain chloroplasts which allow them to
make their own food through a process of
photosynthesis
Understanding the Cell Cycle
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Life begins as a single cell. After becoming an adult, your
body will contain several hundred trillion cells
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Without cell division, living organisms cannot grow and
develop
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In order for each new cell to have a complete nucleus and
complete set of DNA, the cell must go through a process
called mitosis
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Before mitosis can begin, the nucleus must make a copy of
its chromatin so that there are two complete sets of DNA.
This step is called replication
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The replicated chromatin coil up to form a double-stranded
chromosome which are joined in the middle by a
centromere
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Mitosis can now begin
The Phases of Mitosis
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The four phases of mitosis are prophase, metaphase,
anaphase and telophase. These phases always take place
in this order
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The end result of mitosis is the separation of replicated
DNA into two complete nucleus’ with identical sets of DNA
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Animals, plants, fungi and some protists all go through
mitosis, however, animal cells are the only ones that
contain centrioles
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At the end of mitosis, there is still only one cell but now has
two identical nuclei
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The cells now go through cell division
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In animal cells, the cell membrane pinches in near the middle of
the cell dividing the cytoplasm into two new cells
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In plant cells, a cell plate develops across the center of the cell
forming a new cell wall between the two new cells
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In both plant and animal cells, each new cell is an identical
copy of the original
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Mitosis and cell division occupy a small portion of a cell’s life
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The greatest portion of its time is spent in interphase
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During this phase, the cells grow, replicate its DNA and become
prepared for the first phase of mitosis
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Together, the processes of interphase, mitosis an cell division
are called the cell cycle
The Cell Cycle
The Cell Cycle in Your Body
 Responsible
for the growth and
development of all your body cells
 Ensures that the number of chromosomes
in the nuclei of your body remains
constant
 All humans have 46 chromosomes in each
nucleus of their body cells
 Mitosis
and cell division add to the total
number of cells in your body
 The process continues after you are fully
grown because cells do not live forever
 This occurs when they are no longer
needed or cannot function properly
 In your body, approximately three billion
cells die every minute
 Cells also die when they do not receive
enough food or oxygen
 If
you cut your skin or break a bone, the
injured tissue is repaired or remade
through mitosis. This process is called
regeneration.
 As we age, cells die and are replaced
more slowly. This results in changes to the
structure and function of major body
systems
 This results in wrinkles, loss of bone
density, and inability to fight off cancer.
Cancer- The Cell Cycle Out of
Control
Instructions in a cell’s DNA controls the rate of cell
division
 A cell is able to destroy themselves if genetic material in
the nucleus is damaged
 Occasionally the cell divides rapidly with damaged
nuclei. This results in cancer
 Cancerous cells interfere with surrounding cells and
disrupt normal functioning
 They pile on top of one another and produce tumours or
lumps
 They may move to other parts of the organism and
continue to grow
 They steal oxygen and nutrients
 Exposure to tobacco, asbestos, certain chemicals, some
viruses, radioactivity, and UV radiation are linked to
cancer
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Sexual Reproduction