Transcript Cell Division - Beaver Local High School

Cell Division
Section 8.2

All cells are derived from the division
of pre-existing cells

Cell division is the process by which
cells produce offspring cells
Cell division in Prokaryotes

Binary fission- the division of a
prokaryotic cell into 2 offspring cells
Cell division in Eukaryotes

Mitosis- results in new cells with
genetic material that is identical to that
of the original cell

Meiosis- reduces the chromosome
number by half in new cells
The cell cycle

The repeating set of events that make up
the life of a cell

Interphase- the time between cell divisions

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M phase- mitosis
Cytokinesis- the division of the cytoplasm
of the cell
Interphase

G1 phase-offspring cells grow to mature size

S phase- the cell’s DNA is copied

G2 phase- the time gap following the S
phase and preceding cell division

G0 phase- cells do not copy their DNA and
don’t prepare for cell division
Mitosis

Divided into 4 phases: prophase,
metaphase, anaphase, and telophase
Prophase

First phase of mitosis
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Centrosomes- appear next to the
disappearing nucleus
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Centrioles- found in animal cells
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Spindle fibers- made of microtubles
radiate from the centrosomes in
preparation for mitosis

Mitotic spindle- equally divides the
chromatids between the 2 offspring
cells

Kinetochore fibers- attach to
kinetochore

Kinetochore- disk-shaped protein

Polar fibers- extend across the
dividing cell from centrosome to
centrosome
Metaphase

Second phase of mitosis

The kinetochore fibers move the
chromosomes to the center of the
dividing cell
Anaphase

Third stage of mitosis

Chromatids of each chromosome
separate at the centomere
Telophase

Fourth stage of mitosis

Spindle fibers disassemble

Chromosomes return to a less tightly
coiled chromatin state
Cytokinesis

Cleavage furrow- pinches the cell into
2 cells (animal cells)
Cell plate- membrane-bound cell wall
(plant cells)