Transcript 12.1 Identifying the Substance of Genes

10.1 Cell Growth, Division and
Reproduction
Limits to Cell Size

Large cells, more demands

What is information
overload?

Exchanging materials
 Surface area to vol. ratio
 Trouble getting in and out
 Cell
Division – 2 daughters
Cell Division and Reproduction
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Asexual Reproduction
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One parent
No Fuss, No Muss
Quick and Efficient (Survival)
Sexual Reproduction
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Two Parents
Gametes (sex cells)
Genetic Variation
Limit seasonal reproduction
10.2 The Process of Cell Division
Chromosomes
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Why is it necessary for cells to have their info
bundled?

What is the role of the chromosome in cell
division?
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To separate DNA precisely during cell division
Prokaryotic vs. Eukaryotic
Chromosomes

Amt. of DNA – Where located
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DNA Coils
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Histone proteins
The Cell Cycle
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Grows

Prepares for Division

Divides (two daughter cells)
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Prokaryotes
Rapid (binary fission)
 Copy DNA (when they reach a
certain size)
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The Cell Cycle

Eukaryotes
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Four phases
 G1 phase
 Cell Growth
 S phase
 DNA replication
 G2 phase
 Prep for Mitosis
 M phase
 Mitosis and Cytokinesis
Mitosis
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Prophase
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Condense, chromosomes
visible, spindle
Centromere (chrom. Attach.)
Chromatid (sisters)
Centrioles (related to spindle)
Mitosis
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Metaphase
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Centromeres line up in the
center
Spindles attach to centromeres
 Two poles
Anaphase
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Chromatids separate
Move to opposites ends
Mitosis and Cytokinesis
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Telophase (end of mitosis)
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Opposite of Prophase
Chromosome spread out
Nuclear envelope reappears
Spindle breaks up
Nucleolus reappears
Cytokinesis
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Div. of cytoplasm
Plants vs. Animals
Animal
Cell
Plant Cell
10.3 Regulating the Cell Cycle
Controls on Cell Division
 Regulated

by Proteins
When you have an injury cells
must divide to repair
 Regulatory Proteins or
cyclins.
 Internal regulators
 External regulators
 (IR) Make sure chromosomes
are duplicated
 (IR)Programmed cell death
 Apoptosis
 Development
 Parkinson’s
 (ER) Growth Factors – due to
injury
 (ER) Growth Inhibitors so cells
do not get too crowded
Cancer: Uncontrolled Cell Growth

Disorder where cells lose
control of growth

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Do not respond to normal
signals
Tumor – not all are cancerous
 Malignant or Benign
 Defective genes (p53)
Treatments
 Local, radiation,
chemotherapy
10.4 Cell Differentiation
From One Cell to Many

Embryo – Developmental stage
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Differentiation – cells specialized
 Can be mapped
 Determines when a cell
becomes specialized
 Mammals have factors that
give them flexibility as to
when specialization occurs
Stem Cells and Development
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Types of cells in Development
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Totipotent (all cells)
 Blastocyst forms
 Inner cell mass
 Pluripotent (most cells)
 Embryonic stem cells
 Multipotent (many types)
 Adult stem cells
 Depends on where the
come from