Download Chromosomes

Mitosis
and
Cell Division
New Cells
• About 2 trillion new cells each day.
– About 25 million per second!!
• Cell division is also called cell
reproduction.
-
New Cells
• The type of cell division depends on
the type of cell.
– Prokaryotes divide differently than
eukaryotes. -
Mitosis
• Cells getting ready to divide.
– Non-reproductive cells.
• Takes place continuously.
– Except nerve cells. -
Stages of Mitosis
Interphase
• Most of the cell’s life cycle is spent in
this phase.
• Cell increases in size just before the next
phase begins. -
Stages of Mitosis
Prophase
• Mitosis begins.
• All organelles divide so number
doubles.
• All DNA coils up into chromosomes.
• Chromosomes copy themselves. -
Chromosomes
Chromatids
centromere
Sister
chromatids
chromatid
Prophase
Stages of Mitosis
Metaphase
• Chromosomes line up, break apart.
– Each side contains all genetic information.-
Metaphase
Stages of Mitosis
Anaphase
• Broken halves of chromosome pulled to
opposite sides of the cell. -
Anaphase
Stages of Mitosis
Telophase
• Nucleus re-forms.
• Mitosis is complete.
• Cell division almost done. -
Telophase
After Mitosis
• Cytokinesis: Cytoplasm divides and
you have two distinct daughter cells. -
Cytokinesis
Interphase
Inside
nucleus
Then,
tightly
into chromosomes.
DNA iscoils
in long
strands
in the nucleus
Prophase
Inside Cell
nucleus
centromere
Chromosome
Replicated
Chromosome
Metaphase
Inside Cell
Cell
Equator
Anaphase
Spindle fibers
Centriole
Telophase
Cytokinesis