Transcript How Cells Divide - Mrs. Guida's AP Biology Class

How Cells Divide
Chapter 10
Bacterial Cell Division
• Binary Fission
• FtsZ protein
Eukaryotic Chromosomes
• Chromosome Numbers Vary
• Made of Chromatin
Some Vocab
•
•
•
•
•
Karyotype
Haploid
Diploid
Homologue
Chromatids
Overview of the Cell Cycle
•
•
•
•
•
G1
S
G2
M
C
• G0
Interphase
• G1, S, G2
Mitosis
•
•
•
•
•
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Prophase
• Condensation of Chromosome Contintues
• Spindle apparatus
– Asters
• Nuclear envelope disassembles
Prometaphase
• Micrtubules attach to the kinetochore
• Chromosomes begin to move toward the
equator of the cell
Metaphase
• Chromosomes are aligned at the equator
of the cell called the metaphase plate
• Chromosomes are attached to opposite
poles and are under tension
Anaphase
• Proteins holding centromeres of sister
chromatids are degraded, freeing
individual chromosomes
• Chromosomes are pulled to opposite
poles
• Spindle poles move apart
Telophase
• Chromosomes are clustered at opposite
poles and decondense
• Nuclear envelopes reform around
chromosomes
• Golgi complex and ER re-form
•
Cytokinesis
• Plant vs Animal
Control of the Cell Cycle
• Irreversible points
• Checkpoints
MPF
• Nondividing cells can be stimulated into
division by MPF
• MPF activity changes throughout the cell
cycle
• It is cyclin pluc cdc2 (aka Cdk)
– What is a kinase?
Three main Checkpoints
•
•
•
•
G1/S
G2/M
Spindle Checkpoint (APC)
Figure 10.20
Growth Factors
• Trigger intracellular signaling systems
• RTKs and MAP cascades
G0 Phase
• Dormant
• Liver vs Intestinal Lining Cells
Cancer
• Tumor Suppressor genes- p53, Rb
• Oncognes-ProtoOncogenes