warm-up 11/15/10
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Warm-Up 11/15/10• LIST the Phases of the Cell Cycle.
• Which Phase of the CELL CYCLE includes Prophase, Telophase, Anaphase, Metaphase?
• Put the Above-mentioned Phases in the correct Chronological Order.
Warm-Up 11/16/10• Which organism has larger cells?
• How does Size & Shape Affect how efficient a Cell is?
Warm-Up 11/16/10
• Identify the formula for the following:–Surface Area
–Volume
What are the metric units associated with each measurement?
• Identify the formula for the following:–Surface Area
• SA of Rectangle = 2(lw + lh + wh)
• Volume of Rectangle = L x W x H
• What are the metric units associated with each measurement?
– SA Ex: 2 [(2m x 2m) + (2m X 2m) + (2m x 2m)] = 24m2
– Volume Ex: 2m x 2m x 2m = 8m3
• What is the ratio of SA to Volume in the following example?
–SA Ex: 2 [(2m x 2m) + (2m X 2m) + (2m x 2m)] = 24m2
–Volume Ex: 2m x 2m x 2m = 8m3
–SA / Vol = 24m2 / 8m3 = 3 / 1
Warm-Up 11/17/10
• What is the purpose of the Cell Cycle?
• What are the Phases of Mitosis in chronological order?
Exit Ticket
• Identify the differences between the Cell Cycle and Mitosis.
Cell Growth and Reproduction
Section 10.2
CSII-H
Limits to cell growth
• DNA – can only control the needs of a small cell
• Cell Size - cell must have a low surface to volume ratio
• Cell Division – when a cell gets too large to control or function efficiently, cell division takes place
Cell Cycle
• Growth
• Nuclear division
• Cytoplasmic division.
Warm-up
• What are the 4 phases of mitosis?
– Prophase– Metaphase– Anaphase– Telophase
Interphase
• G1 – growth phase –> cell gets bigger and develops.
• S – synthesis phase –> DNA in nucleus is copied.
• G2 – growth phase –> more growing and developing; produce more organelles, enzymes, centrioles are replicated, etc.
Mitosis
• Nuclear division
• Yields 2 daughter nuclei that are genetically identical.
• Used for Growth and Healing.
Prophase• Chromatin condenses into
chromosomes, 2 identical strands of DNA attached by a centromere.
• Centrioles move to opposite ends of the cell.
• Nuclear envelope and nucleolus disappear.
• Spindle starts to appear.
Metaphase
• Chromosomes line up on Metaphase Plate between the centrioles.
• Spindle fibers attach to chromosomes at centromeres.
Anaphase• Centromeres are pulled apart
as spindle fibers contracts.• Chromatids (half of a
chromosome) are pulled in opposite directions.
• Chromatids are pulled to opposite ends of the cell.
Telophase
• Chromatids complete journey to the ends of the cell.
• Chromatin is formed as DNA elongates.
• Nuclear envelope forms around each set of DNA.
• Spindle disappears
• Nucleoli appear in each nucleus
Cytokinesis
• Cytoplasmic Division
• Begins during anaphase
• Furrow / ring starts to develop in the middle of the cell membrane
Cytokinesis
• In plants, you start to develop a cell plate
• Ring contracts until it completely separates the two new nuclei and about ½ organelles into each new cell
Control of the Cell Cycle
• Cyclins (proteins) regulate cell growth
• Internal regulators – only move to the next phase of the cell cycle when the previous phase is complete
Control of the Cell Cycle
• External regulators – if there is room, a cell divides; if neighboring cells are touching, cell growth is inhibited because space is scarce
Cancer
• Uncontrolled cell growth.
• Tumors are cells that do not respond to cell regulators.
• Results from a loss of regulation / control during the cell cycle.
Apoptosis
• Normal part of development for most cells in a multi-celled organism.
• Special enzymes will break cells down.
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