The document discusses cell division, emphasizing that all cells originate from pre-existing cells and that DNA must be replicated prior to division to ensure each new cell receives an identical set. It details the four stages of mitosis (prophase, metaphase, anaphase, telophase) and the process of cytokinesis, which divides the cytoplasm into two identical daughter cells. Additionally, it contrasts the processes in plant and animal cells during cytokinesis.

2. Cell Division
All cells are derived from pre-
existing cells
New cells are produced for
growth and to replace damaged or
old cells
Differs in prokaryotes (bacteria)
and eukaryotes (protists, fungi,
plants, & animals)
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3. Keeping Cells Identical
The instructions for
making cell parts
are encoded in the
DNA, so each new
cell must get a
complete set of the
DNA molecules
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4. DNA Replication
 DNA must be copied or
replicated before cell
division, Original DNA
 DNA is untwisted and strand
separate.
 Every nitrogenous bases
on the strands will pair
up with its suitable base
that floats in the
nucleus.
 Each new cell will then
have an identical copy of
the DNA
Two new, identical DNA strands

5. DNA Shape
Double helix: 2 spirals wound around
each other
But joined in
the middle

6. What’s Happening in Interphase?
What the cell looks like
Animal Cell
What’s occurring
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7. Mitosis
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8. Chromosomes in Dividing Cells
Duplicated
chromosomes are
called chromatids
& are held
together by the
centromere
Called Sister Chromatids

9. Four Mitotic Stages
Prophase
Metaphase
Anaphase
Telophase
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10. Mitosis
• Prophase:
• Chromosomes condense
• Nuclear envelope disappears
• centrosomes move to opposite sides of the cell
• Spindle forms and attaches to centromeres on the chromosomes
• Metaphase
• Chromosomes lined up on equator of spindle
• centrosomes at opposite ends of cell
• Anaphase
• Centromeres divide: each 2-chromatid chromosome becomes two
1-chromatid chromosomes
• Chromosomes pulled to opposite poles by the spindle
• Telophase
• Chromosomes de-condense
• Nuclear envelope reappears
• Cytokinesis: the cytoplasm is divided into 2 cells

11. Cytokinesis
 Means division of the cytoplasm
 Division of cell into two, identical halves
called daughter cells.
 In plant cells, cell plate
forms at the equator to
divide cell.
 In animal cells, cleavage
furrow forms to split cell
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12. Cytokinesis
Cleavage furrow Cell plate in
in animal cell animal cell
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13. Revise and Test Yourself
Review
of
Mitosis
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14. Name the Mitotic Stages:
Interphase
Name this?
Telophase Prophase
Name this?
Metaphase
Anaphase
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