Download 10-2 Cell Division

Chapter 10: 10-2 Cell Division
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genetic info is carried by chromosomes
made of DNA and proteins
Humans = 46 chromosomes (23 pair)
not visible until cell division begins
before cell division each chromosome is replicated or
copied.
Each chromosome consists of two
identical sister chromatids (B)
Centromeres are located in center of
chromatids (A)
period between cell division is called Interphase
 cell cycle is a series of events that cells go through as
they grow and divide.
 During the cell cycle, a cell grows and prepares for
division, and divides to form 2 daughter cells, each of
which then begins the cycle again.
o M phase, G1, Synthesis, G2 back to mitosis
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Interphase:
o G1  growing, protein synthesis, metabolism
o S synthesis of DNA, chromosomes are
replicated.
Chapter 10: 10-2 Cell Division
o G2  (shortest) final preparation before Mitosis
o Cell is ready for Cell Division!
 Biologists divide the events of mitosis into four
phases: Prophase, metaphase, anaphase, and telophase
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1st and longest phase
Chromosomes become tightly coiled and visible
Centrioles migrate toward poles (not in plants)
Spindles form—a fanlike microtubules
structure that helps separate
chromosomes.
nucleolus disappears
nuclear envelope break down
2nd phase (usually shortest)
chromosomes line up across the center
of the cell.
Microtubules connect centromere to
spindle.
3rd phase
sister chromatids separate and become
individual chromosomes
Chapter 10: 10-2 Cell Division
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move toward poles
ends when chromosomes stop moving
4th and final phase
chromosomes uncoil back to tangled
chromatin
nuclear envelope re-forms
spindles break apart
nucleolus becomes visible in each daughter cell.
mitosis is complete
mitosis is the division of the nucleus
Cytokinesis is the division of the cytoplasm
cell membrane pinches in
In plants, cell plate forms in
between each nuclei and
eventually become the cell
wall.