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WELCOME TO BIOLOGY 112!
Biology is about making observations of living things
What observations can you make about this cartoon?
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Resources on my web site:
Lectures Outlines/notes Homework/extra credit assignments Review Materials, Objectives Syllabus (link on main lecture page) Prelabs are also on my lab web site.
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Admin:• Pass out outline of notes and syllabus• Go over syllabus
This Class is HARD!
Don’t procrastinate Try to study every night Details matter You’ll need to know all this stuff for micro &
A&P Ask me if you have questions
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General Info FOOD: ok in lecture room (as long as it’s
quiet); NONE allowed in lab PHONES: please turn it off; if you need to
make / take a call, be respectful and go outside. Penalty if it rings a 2nd time!
IN GENERAL: be respectful of everyone in the class
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Chapter 1: Why Study Biology? Biology: scientific study of life Important to study and understand life in a
scientific wayAwareness and appreciation of life Important in decisions of life Issues dealing with biology arise daily
Characteristics of Life
• What things in this picture are living?
• What things are non-living?
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Characteristics of Life
Bacteria Is it living?
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Characteristics of all living things What are some characteristics that are
shared by all living things but NOT by non-living things?
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Characteristics of all living things1. CELLULAR ORGANIZATION
2. METABOLISM
3. HOMEOSTASIS
4. GROWTH
5. REPRODUCTION
6. HEREDITY
7. EVOLUTION
Today and through the term, we’ll be discussing these properties of life
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1 - CELLULAR ORGANIZATION
Living things are composed of CELLS Self-contained living units Unicellular (single cell) Multicellular (many cells)
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Cells/organisms are highly Organized
Complex function Organization is required
for function
Humans have organ and tissue systems
Even bacteria have organization
Characteristics of life2. Metabolism
All the chemical reactions involving the energy and materials acquired and converted to another form by an organism.Living Things Acquire/Use Materials and
Energy from their Environment and Convert them into useful products.
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2 - METABOLISM Collect energy from their
environment and use it to grow and develop
Energy of sunlight – Photosynthesis Energy from other living organisms –
Cellular Respiration
Metabolism examples
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MOVEMENT
PHOTOSYNTHESIS
Thru Metabolism Life Responds to the Environment
Energy gives the organism the ability to respond to environmental stimuli
This response involves metabolism
Many organisms have multiple senses Smell, hear, taste, touch,
and see
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Response to Environment
Senses often different than a human’s Ultraviolet/infrared light Electrical/ultrasonic fields Magnetic fields
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Response to Environment
Senses often different than a human’s Detection of chemicals
(flies/insects)
This response involves metabolism and may change the metabolism of the cell
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3. Homeostasis Life Actively Maintains its Structure and its Internal Environment.
Organisms respond to env changes to keep their internal operating conditions within tolerable limits, else they …
Characteristics of life
3 - HOMEOSTASIS
Ability of an organism to keep internal environment of cell or organism relatively constant compared to outside environment
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HOMEOSTASIS
Uses Regulation to keep the internal environment of cell or organism relatively constant compared to outside environment
Regulation and homeostasis are very similar
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Regulation
Done in various ways. Example, we keep
our internal environment relatively constant in our glucose levels by either releasing or storing glucose.
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-Regulation
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ANIMAL TEMPERATURE - BEHAVIORS
PLANT CARBON DIOXIDE - STOMATA
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4 - Growth and Development
DNA as a blueprintOrganisms grow and propagate themselvesOrganisms develop and grow in complexity
Growth and Development
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(3) Living things grow and develop
5 - Reproduction
Living organisms reproduce or replicate themselves
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Reproduction
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EGG AND SPERM POLLEN, FLOWERS, SEEDS
6 - Heredity
Genetic material (DNA) is passed from parents to offspring
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7 - Evolve
Mistakes are made in replicating DNA Causing the characteristics of a population to
change
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4. Living Things Grow,
5. Reproduce
6. Using DNA (Heredity)
7. and have the Capacity to Change & Evolve
Last 4 Characteristics of life:
DNA -deoxyribonucleic acid ... molecule encoding for life. DNA is inherited ... offspring from its parent(s).
DNA ... instructions for all traits, proteins and RNA. Errors occur in replicating DNA overtime
Life has been around for 3.8 billion years ... lot of time for new variants t.... and better use their environment.
Evolution is a change in a population over time occurring mainly from mutation and natural selection. These changes ... DNA.
In life’s hierarchy of organization, new properties emerge at each level
Life’s levels of organization define the scope of biology– Life emerges through organization of various
levels– Each level is built from one or more lower
levels– With addition of each new level, novel
properties emerge
Biosphere
Ecosystem
Community
Population
Nucleus
Cell
Tissue
Organ
OrganelleMolecule
Atom
Organism Brown pelican
Organ system
Life’s Hierarchy
Biosphere
EcosystemFlorida coast
CommunityAll organisms onthe Florida coast
PopulationGroup of brown
pelicans
Organism Brown pelican
Life’s Hierarchy
Nucleus
Nerve
Spinal cord
CellNerve cell
TissueNervous tissue
OrganBrain
OrganelleNucleus Molecule
DNA
Atom
Organism Brown pelican
Organ systemNervous system
Brain
Life’s Hierarchy
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Organization of Life
Atoms Smallest unit of elements*
Molecules Smallest unit of compounds*
Cells Smallest unit of life
Populations The unit that changes with time
* Will be discussed in chemistry
Species vs PopulationPopulation –cats in an area
Species –all kitty cats
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What’s a species?
A group of organisms that can interbreed and produce fertile offspring
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Why “fertile offspring”?
The mulehorse-donkey
hybridCannot breed
Levels of Classification
Scientists way of making sense of over 1.8 million different types of organisms
Group similar organisms into ever bigger groups
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Levels of Linnaean Hierarchy
Seven levels Add Domains for
eight
Levels of Classification
How do we classify all these organisms?
Levels of Classification
How do we classify all these organisms?
Single-celled prokaryotes
Single- or multi-celled eukaryotes
Single-celled prokaryotes
Classification: The Tree of Life The Tree of Life is based on DNA
sequence similarity
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Evolve vs Grow
EVOLVE: Species change over generations
GROW: Individuals change over organism’s lifespan
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Father of Evolution
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Darwin’s Theory of Natural Selection Individuals in a
population vary in their traits
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Darwin’s Theory of Natural Selection Individuals in a
population vary in their traits
More offspring are produced than the environment can support
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Darwin’s Theory of Natural Selection Individuals in a
population vary in their traits
More offspring are produced than the environment can support
Better-suited individuals reproduce more
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Natural Selection Overview
Natural selection occurs as heritable variation responds to environmental factors that favor the reproductive success of some individuals over others
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Current Example of Evolution – Multidrug-resistant Bacteria
EvolvedR to Penicillin obtained from a Mold Staphylococcus
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Biological Diversity
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Theory of Evolution explains the diversity seen in the natural world
Review of the Properties of Life
CELLULAR ORGANIZATION (or ORDER)
HOMEOSTASIS or REGULATION
GROWTH and DEVELOPMENT
METABOLISM and/or RESPONSE TO ENVIRONMENT
REPRODUCTION with DNA
HEREDITY (DNA) EVOLUTION
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-Review of Cells
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ANIMAL CELL
PLANT CELL
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CELL SIZE COMPARISON
-Review of Cells
• Animal• Plant• Bacteria• Noncellular
viruses
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SUMMARY
All living things share certain characteristics
The differences between living and non-living are not clear-cut
Levels of organization define biology and Different properties emerge at each level
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SUMMARY
All living things share certain characteristics
The differences between living and non-living are not clear-cut
Living things are classified into domains and kingdoms
Levels of organization defines biology
The Scientific Method:How Scientists ThinkDeductive Reasoning Makes a decision by
applying a general principle
Inductive Reasoning Makes a general principle
by applying many different specific observations
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Should I touch this piece of metal?
Two Approaches to Science
1. DISCOVERY SCIENCE No experiments Based on observations Inductive reasoning –
general principles derived from large number of specific observations
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EXAMPLE: All living things are composed of cells
Two Approaches to Science
1. HYPOTHESIS-BASED SCIENCE Involves carefully planned experiments Based on observations Deductive reasoning – takes a general
statement and extrapolates specific results we would expect
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How Scientists Think
Biology is a science, and all science must have merit, or it will not be accepted .... How do scientists ensure that their facts and theories are accepted by others? ...the scientific method!
Pasteur's hypothesis testing of spontaneous generation.
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The Scientific Method1. make an observation. Observe some aspect of
nature and ask a question about it.. 2. develop a hypotheses about a possible answer
or solution to your question.3. use hypotheses to make a prediction about ...
observe next, devise ... test your prediction with an experiment.
4. if results do not confirm the hypothesis, discard or modify it. Otherwise, repeat devise new tests to confirm your results.
5. make a conclusion by analyzing ... Report your findings.
The Scientific Method hypotheses -an educated guess about an
observation. ...not been tested. theory -in common English, an explanation
for an observation or an educated guess. scientific theory -an explanation that has
not been disproved after years of rigorous testing. ... used ... to explain additional observations. Evolution ... main theory underlying all biology.
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Example OBSERVATION: Millions
of fish are periodically killed in mysterious die-offs in the mid-Atlantic. Their bodies are covered in bleeding sores.
QUESTION: What is causing this to happen to these fish?
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Hypothesis
What is an hypothesis? A testable explanation
that explains an observation
Addresses the question which came from the observation
Example Hypothesis: A microscopic protist, Pfiesteria, was killing the fish
What is your hypothesis about the fish die-offs?
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Predictions
Based on the hypothesis Can be tested Example—two testable predictions
Pfiesteria would be found in larger numbers during the die-offs
Pfiesteria would be capable of killing healthy fish
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Experiments Designed to test the predictions Results either support or refute hypothesis An experiment should only test ONE thing
(the variable) Everything else should be the same
(constant) You need something to compare to (control)
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Experiments
Results from testing Pfiesteria was found where fish were dying Pfiesteria quickly killed the fish in the laboratory Pfiesteria infect and kill fish cells
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Conclusion
Does the evidence presented support or refute the Pfiesteria hypothesis?
Note in science, we can disprove a hypothesis (refute it), but we can never prove it.
A disproven hypothesis can be revised to include new information.
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The Scientific Process does not…
Make moral judgments Prove or disprove faith-based beliefs Determine personal aesthetic values Produce a FINAL answer because it is
always open to more testing. You can only support a hypothesis, not prove it.
Experiment
Does Brand X fertilizer really help my plants grow?
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WATER
WATER +
FERTILIZER
Controlled Experiments Have:
TWO GROUPSExperimental groupControl group
INDEPENDENT VARIABLE – the one thing in the experiment different between the two groups. What you change in your experiment
CONSTANT Variables – the things that are the same between the groups
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Controlled ExperimentControl Group Experimental Group
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WATER
WATER +
FERTILIZER
INDEPENDENT VARIABLE?CONSTANTS?
Controlled Experiments
DEPENDENT VARIABLE – the thing (or things) in the experiment that you are measuring
The dependent variable DEPENDS on the independent variable
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Control Group Experimental Group
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WATER
WATER +
FERTILIZER
DEPENDENT VARIABLE?HINT: the dependent variable depends on the independent variable
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Scientific Method - Discussion Problems Find a partner Discuss each scenario with your partner,
then share with the group Scientific Method problems