Chapter 4
CELL REPRODUCTION
CELL DIVISION AND MITOSIS
Cell cycle-every cell has a lifecycle –
birth, growth and development and
death
Length of cycle varies
I PMAT
INTERPHASE
When a cell copies its genetic
material (chromosomes) in the
nucleus and prepares for cell division
PROPHASE
Nuclear membrane disappears
Centrioles move to opposite ends of
the cell in an animal cell
Spindle fibers begin to form in
animal and plant cells
METAPHASE
Pairs of chromatids line up across
from each other (like football line of
scrimmage)
Spindle fibers connect to centomere
of each pair of chromatids
ANAPHASE
Spindle fibers pull chromosomes to
opposite ends of the cell
TELOPHASE
Spindle fibers disappear
Chromosomes become encased in a
new nuclear membrane
TELOPHASE
Cell membrane pinches in and the
cytoplasm divides for an animal cell
and two new identical cells are
formed - cytokinesis
In a plant cell a new cell plate forms
as the cell divides and will become a
new cell wall for the new cells
Process repeats itself
cytokinesis
RESULTS OF MITOSIS
Two new, identical cells form from
mitosis
Mitosis is for growth and repair of
organism
ASEXUAL REPRODUCTION
Only one parent needed
Offspring are identical to the parent
Some plants reproduce by sending
out shoots or runners, strawberry
plant
ASEXUAL REPRODUCTION
Fission – when one organism divides itself
in two
Budding – a new organism grows off the
side of the parent and then releases when
ready
Regeneration – process of regrowing a lost
body part, or forming new, identical
organisms from the separated body part –
seastar or sponges