Download Cell Cycle

“Cell division is
part of the cell
cycle”
Section 3.2 & 3.3
Do Now
• Label the following diagram
• 1- chromosome
• 2- chromatid
• 3- centromere
Objectives
• Describe the main events of the cell cycle
• Differentiate interphase from mitosis
• Construct a cell cycle model from paper plates.
Cell Cycle
• “normal sequence of development and division of a cell”
• Two main phases: Interphase & M-phase (Mitosis)
Interphase
• There is no division in interphase, just growth.
G1: organelles duplicate, cell grows
S: DNA replicates (is copied)
G2: cell grows, prepares to divide
M-phase (Mitosis)
• Mitosis= “nuclear division”
• PMAT+ C
•
•
•
•
•
Prophase
Metaphase
Anaphase
Telophase
Cyokinesis
Plate Models
• You are now going to make a study tool using
paper plates.
• Follow along while I show you how to fold the
plate, use the directions as a guide.
• Pass out plates
Mitosis
• Creates 2 genetically IDENTICAL daughter cells.
Prophase
• DNA condenses to form chromosomes.
• Each chromosome has 2 chromatids and a centromere
• The nuclear membrane disappears
Metaphase – “Middle”
• Chromosomes line up in the middle of the cell at the
“equator”
Anaphase – “away”
• Chromatids split
• Spindles pull to opposite sides of the cell AWAY
from each other
Telophase
• 2 Nuclei form
• Nuclear membrane forms
around each group of
chromosomes.
• The chromosomes become
chromatin again.
Cytokinesis
• Division of the
cytoplasm.
• Occurs differently in
plant and animal cells.
• 2 New daughter cells!
Cytokinesis
• Animal Cells:
• Membrane pinches together and
forms a cleavage furrow until the
cells separate.
Cytokinesis
• Plant Cells:
• Cell plate forms which
becomes the cell wall and
divides the two cells.
Section 3.3
“Both sexual and
asexual reproduction
involve cell division”
• Eukaryotic cells divide by mitosis
and cytokinesis.
• Ex: skin cells apart of skin tissue
(aren’t independent)
• Most unicellular organisms use
cell division to reproduce
through asexual reproduction.
• Asexual Reproduction: one
organisms produces one or
more new organisms that are
identical to itself and that live
independently of it
Binary Fission
• A form of asexual reproduction
occurring in prokaryotes.
• The parent organism splits in
two, creating two independent
daughter cells.
• Genetically all the same!
Budding - Organism develops tiny buds on its body.
• Genetic material the same!
• Can bud anywhere OR specialized
cells in certain parts of the body.
• Detaches when it reaches a
certain size
• Both unicellular and multicellular
can reproduce by budding.
Hydra
Regeneration
The process of new
tissue growth at sites
with wounds or lost
limbs.
Bacteria
Many bacteria have a very short
generation time.
Some can have a new generation of
cells in less than 30 min.