Transcript Mitosis Notes

MITOTIC CELL DIVISION
Miss Charney
Northville
Central School
WHY DO CELLS
REPRODUCE?
• Form of reproduction requiring only one
parent called asexual reproduction
• Growth
• Repair and replacement of cells and/or cell
parts
WHAT IS MITOSIS?
• Definition: process by which a cell’s
genetic material divides, creating two
complete sets of the cell’s genetic material
• Result: Two daughter cells that are
genetically identical
CHROMOSOME STRUCTURE
chromatid
Chromosomes are
composed of the
following:
telomere
centromere
1. Chromatids: paired
strands that compose
the chromosome
2. Centromere: tiny
disk holding
chromatids together
telomere
Condensed, duplicated chromosome
INTERPHASE
•
Definition: resting
stage that occurs
between cell
divisions
•
Involves 3 events:
1. Cell growth
2. Copying of DNA, or
replication
3. Centrioles replicate
STAGE 1:
PROPHASE
• Chromosomes become
clearly visible
• Nuclear membrane
disintegrates
• Centrioles move to
opposite ends, or poles,
of the cell
• Thread-like structures
called spindle fibers
appear and extend
between centrioles
STAGE 2:
METAPHASE
• Chromosomes align in
the center of the cell,
or equator
• Chromosomes are
attached to spindle
fibers via centromeres
STAGE 3:
ANAPHASE
EARLY ANAPHASE:
• Sister chromatids split
• Chromatids move away
from equator and toward
the poles
LATE ANAPHASE:
• Cell membrane begins to
pinch forming a
cleavage furrow
STAGE 4:
TELOPHASE
• Two nuclear
membranes form
• Spindle fibers disappear
• Cell membrane
continues to pinch in
and cytoplasm equally
divides, a process
known as cytokinesis