Hand in W.S. 6.2 before the bell rings

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Class Topics
Title Biology 12/12/06
Objectives

• To begin learning about Chapter 6

• Hand in W.S. 6.2 before the bell rings
• Review for Chapter 6 Quiz 1
• Notes - mitosis
• Nothing great was ever achieved without
  enthusiasm.
• Ralph Waldo Emerson

Wednesday, October 12, 2016 1058 AM
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Finals Schedule12/15/06 - 12/21/06

• Revised lunch schedule
• Friday the bus leaves at 1040
• Buses run at regular times Mon, Tues, and Wed
• Thursday the bus leaves at 1100

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Class Assignments
By When
What

• W.S. 6.2 (DR/Quiz) 12/12/06
• Chapter 6 Quiz 1 12/14/06
• Due this class period
• Due next class period
• Due in the future

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Grade Sheet
1A SR p. 61 - 5 pts Measurement W.S. 10 pts
3A SR p. 42 6 pts
4A SR p. 47 5 pts
2A Measurement W.S. 10 pts SR p. 80 5 pts
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Postquiz Activities

• Read

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Length of cell cycle

• Ranges from 20 minutes to 20 hours
• Some cells divide constantly and others never
  divide
• Muscle cells
• Red Blood cells
• Skin cells
• Bone cells
• Nerve cells

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Mutation(Handout)

• Changes in chromosome structure
• Deletion
• Cri du chat syndrome
• 5p deletion
• Translocation
• 14-21
• Another cause of Down Syndrome

From http//www.criduchat.asn.au/criduchat/what.h
tmDiagram201
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Cell Cycle

• G1 - growth and normal cell activity
• G0 never divides again
• S - Synthesis of DNA
• DNA replication, Copying DNA, forming chromatids
• G2 - Growth for division, organelles double
• Mitosis - Division of the nucleus
• Cytokinesis - Division of the cytoplasm (cell)
• Interphase (longest phase)
• G1, S, G2, (G0 as well)

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Controlling the cell cycle

• Checkpoints
• 1. Cell growth (G1)
• to begin DNA synthesis
• Entry point for G0
• 2. DNA synthesis (G2)
• Checking for errors in DNA
• 3. Mitosis
• Exiting mitosis, beginning of G1
• A build up of proteins (cyclins) stimulate the
  move to next stage

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http//stemcells.nih.gov/info/scireport/appendixA.
asp
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Chapter 6 Quiz 1 Review

• Matching
• Centromere, chromatid, DNA, somatic cell, gamete
• Multiple choice
• Chromatin, diploid, gene, haploid, prokaryotic
  cell division
• Short Answer
• Human chromosome number, pairs of human
  chromosomes, sex chromosomes
• Mutation
• Deletion, translocation
• Cell cycle labeling

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Cancer

• What do you know about cancer?
• Uncontrolled cell growth
• Cells stop responding to control mechanisms
• Read p. 127

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Exploring Further

• What causes the damage to genes controlling the
  cell cycle?
• Carcinogens
• What do they do?
• Stepping on the Accelerator
• oncogenes
• Releasing the Brakes
• Tumor supressor genes

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Mitosis

• A process in which eukaryotic cells form two
  identical nuclei.
• Each cell receives a complete set of chromosomes
• Karyokinesis
• division of the nucleus - actual process of
  mitosis - not in prokaryotes
• Cytokinesis
• division of the cytoplasm, true cell division
• 2 exact replica independent cells
• Different in plant and animals

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Preparation for Mitosis

• Formation of spindles
• Microtubules and centrioles that move the
  chromosomes
• Centrioles form poles (only in animals)
• Microtubules of spindle attach to centrioles and
  centromere of chromosomes

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Mitosis

• Prophase
• Metaphase
• Anaphase
• Telophase

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Prophase

• 1st phase of mitosis (longest) -
• chromosomes begin to coil up from chromatin
• Centrioles appear
• Not in plants
• Organize microtubules and create spindle
• Spindle fibers appear
• clusters of microtubules

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Metaphase

• chromosomes move to the center of the cell
• equator
• metaphase plate
• Shortest phase

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Anaphase

• Chromosomes separate at the centromere
• Completed when movement stops

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Telophase

• Opposite of prophase
• chromosomes uncoil into chromatin
• Centrioles disappear (animals)
• Spindle fibers disappear
• Distinct nuclei are formed
• Beginning of cytokinesis (usually)

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Cytokinesis - Forming Daughter Cells

• Animal
• Cleavage furrow
• Dividing a balloon in two

• Plant
• Cell plate
• Dividing a room in two