cells and cellular processesion.uwinnipeg.ca/~jfranck/bio1115_fall_2008/adobe files/biology t… ·...
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Cells and Cellular Processes
Biology 05.1115/3Biology 05.1115/3Fall 2008Fall 2008
Introduction
• Instructor: Dr. Jens Franck• Ph. (204) 789-1411• [email protected]• Rm 3L04 (Lockhart Hall)
Mark Breakdown• Lecture Midterm Exam 20%• Lecture Final Exam 40%• Lab Midterm Exam 10%• Lab Final Exam 25%• Lab Assignments 5%
• Total 100%
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A+ 90-100%A 85-89%A- 80-84%B+ 75-79%B 70-74%C+ 65-69%C 58-64%D 50-57%F <50%
����������� ���• Lab Instructor: Beata Biernacka
• Rm 4C71• [email protected]
• Lab Location: 3C42 (Centennial Hall)• Labs Start week of September 8th
• Purchase Lab Book prior to first lab at Petrified Sole Bookstore (Bulman Centre)
• The lab has a WebCT based web site (for all students in all lab sections)
• Transfer between sections possible afterfirst week of labs
• If you are waitlisted, attend the lab of your choice
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• Lectures• Textbook
• Text• CD-ROM• Text Website
• Course Website (WebCT server)• PowerPoint Slides• Class mail• https://claimid.uwinnipeg.ca/claimid
• Me
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What is Life ?• Life is highly organized• Life reproduces• Life responds to environment• Life takes in energy (and transforms it)• Life shows growth and development• Life adapts to its environment
What is Life ?
• Life is highly organized
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���� ���������• Short term response to the environment
���� ���������• Life takes in energy and raw materials
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• Homeostasis• “Regulation”
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���� ���������• Life shows growth and development
���� ���������• Adaptation: Life adapts to its
environment through natural selection (evolution)
Pygmy Seahorse
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• Biologists explore life from the microscopic to the global scale
• The study of life• Extends from the microscope scale of
molecules and cells to the global scale of the entire living planet
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• From the biosphere to organisms
Figure 1.3
1 The biosphere
Biosphere
Ecosystem
Community
OrganismsPopulations
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• From cells to molecules
Cell
8 Cells
6 Organs and organ systems
7 Tissues
10 Molecules
9 Organelles
50 µm
10 µm
1 µm
Atoms
Figure 1.3
Ecological Level of Organization
• Organism• Population• Community• Ecosystem
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"�����#��$�%!����!�"����� �• Living organisms and their environmental
form interconnecting webs
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• The dynamics of any ecosystem include two major processes• Cycling of nutrients, in which materials
acquired by plants eventually return to the soil
• The flow of energy from sunlight to producers to consumers
The Study of Life• Chemical Level of Organization
• Atoms• Molecules• Macromolecules
Carbohydrates LipidsProteinsNucleic Acids
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Atoms
MoleculesMacromolecules
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The Study of Life
• Cellular Level of Organization• Organelles• Cells• Tissues• Organs• Organ Systems• Organism
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%$��&����#������������• All cells share certain characteristics
• They are all enclosed by a membrane• They all use DNA as genetic information
• There are two main forms of cells• Eukaryotic• Prokaryotic
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• Prokaryotic cells• Lack the kinds of membrane-enclosed
organelles found in eukaryotic cellsEUKARYOTIC CELL
Membrane
Cytoplasm
Organelles
Nucleus (contains DNA) 1 µm
PROKARYOTIC CELL
DNA (no nucleus)
Membrane
Figure 1.8
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• Cells contain chromosomes made partly of DNA, the substance of genes
Egg cell
Sperm cell
NucleicontainingDNA
Fertilized eggwith DNA fromboth parents
Embyro’s cells with copies of inherited DNA Offspring with traits
inherited fromboth parentsFigure 1.6
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The Continuity of Life
• All life uses DNA to store and inherit genetic information
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DNA directs cell metabolism and development
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• Due to increasing complexity• New properties emerge with each step
upward in the hierarchy of biological order
Cell
8 Cells
6 Organs and organ systems
7 Tissues
10 Molecules
9 Organelles
50 µm
10 µm
1 µm
Atoms
Figure 1.3
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• The study of DNA structure, an example of reductionism• Has led to further study of heredity,
such as the Human Genome Project
Figure 1.9
��� ����������• Systems biology
• Seeks to create models of the dynamic behavior of whole biological systems
• With such models• Scientists will be able to predict how a
change in one part of a system will affect the rest of the system
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CELL
Nucleus
Cytoplasm
Outer membraneand cell surface
Figure 1.10
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• Concept 1.3: Biologists explore life across its great diversity of species
• Diversity is a hallmark of life
Figure 1.13
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Species Genus Family Order Class Phylum Kingdom Domain
Mammalia
Ursusameri-canus(Americanblack bear)
Ursus
Ursidae
Carnivora
Chordata
Animalia
EukaryaFigure 1.14
%!����������������Three Domains of Life•Eukarya•Bacteria•Archaea
Common Ancestor?
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The Diversity of Life• Three domains
• Bacteria
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Archaea
%!������� ��������• Domain Eukarya
Protists
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
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Evolution
Evolution, Unity, and Diversity
• Diversity and unity are the dual faces of life on Earth
• Evolution is the core theme of biology
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• As diverse as life is• There is also evidence of remarkable
unity
Cilia of Paramecium.The cilia of Parameciumpropel the cell throughpond water.
Cross section of cilium, as viewedwith an electron microscope
15 µm
1.0 µm
5 µm
Cilia of windpipe cells. The cells that line the human windpipe are equipped with cilia that help keep the lungs clean by movinga film of debris-trapping mucus upward.Figure 1.16
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)� �������� ���• Population’s heritable variations exposed to
environmental factors that favor the reproductive success of some individuals over others
1 Populations with varied inherited traits
2 Elimination of individuals with certain traits.
3 Reproduction of survivors.
4 Increasing frequency of traits that enhancesurvival and reproductive success. Figure 1.21
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Webbing between digits makes bats adapted for flight.
Bat Skeleton
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Adaptive Radiation ofGalapagos Finches“Descent with Modification”
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• Inquiry is at the heart of science• A search for information and explanation,
often focusing on specific questions
• Two main processes of scientific inquiry• Discovery science• Hypothesis-based science
Hypothesis Based Inquiry
•Observation: The flashlight won’t Work.•Hypothesis 1
•Batteries are Dead
•Test Hypothesis•Replace Batteries
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• Results of Experiment• After replacing batteries: Flashlight still
doesn’t work
• New Hypothesis• Bulb is burnt out
• Test New Hypothesis• Replace Bulb
• Results of Experiment 2• After replacing bulb, flashlight now works.
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Flashlight Problem•Flashlight doesn’t work
•Formulate Hypotheses•Test Hypotheses
Scientific Method• Observation• Hypothesis• Experiment• Analysis
• Support or reject hypothesis
• New Hypothesis• Experiment - etc.
• In mimicry• A harmless species resembles a
harmful species
Flower fly(non-stinging)
Honeybee (stinging)Figure 1.26
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Controlled Experiment
Investigating Mimicry in Snake Populations
Eastern Coral Snake (poisonous)
Scarlet King Snake (non-poisonous)
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Field Experiments with Artificial Snakes
Controlled ExperimentExperimental group • artificial King snakesControl group • Brown artificial
snake
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Fig. 1-27
Artificial kingsnakes
Brownartificial snakes
83% 84%
17% 16%
Coral snakesabsent
Coral snakespresent
Per
cent
of t
otal
att
acks
on a
rtifi
cial
sna
kes
100
80
60
40
20
0
EXPERIMENTAL RESULTS