Transcript Cell Growth & Division - Whitman

Eukaryotic Cell Division
•Stage 1: Mitosis
• Stage 2: Cytokinesis
Interphase-(the long period)
• G1 Phase: Cell grows, makes
new proteins and organelles
• G0 Phase: Cells “hang out” and
perform usual functions
• S Phase: DNA is replicated
• G2 Phase: Organelles required
for division are synthesized
•The shortest part of the
cell cycle
•Lasts from a few minutes
to several days
•Consists of 4 Phases:
-Prophase
-Metaphase
-Anaphase
-Telophase
• Nuclear envelope
dissolves
• Nucleolus disappears
• Chromosomes become
visible
• Centrioles move to poles
• Spindle fibers form
• Chromosomes line up at the
equator (center)
• Spindles connect to the
centromere of each chromosome
• Centrioles split chromosomes
into sister chromatids
• Phase ends once
chromatids
reach the poles
• Chromosomes uncoil
• A nuclear envelope
surrounds DNA
• Nucleolus re-forms
• Spindle fibers break down
• Cell division is not complete!
•Divides cytoplasm
In plants, a
cell plate
Forms
new
forms
cell
wall!
between the
2 new cells
Meiosis
During sexual
reproduction, gametes
(sperm or eggs) are
produced by each parent
Gametes contain half
the number of
chromosomes found in
most cells
When gametes unite, the
zygote then has the
normal number of
chromosomes
Dad’s
Mom’s
chromosomes
chromosomes
Dad’s
Mom’s
gametes
gametes
zygote
Diploid vs. Haploid
DIPLOID: Contains
BOTH sets of
chromosomes (1
from each parent)
HAPLOID: Contains 1
set of chromosomes
to combine during
sexual reproduction
with another to form
a DIPLOID cell.