Transcript Chapter 1 Art Slides

WELCOME TO BIOLOGY 112!

Biology is about
making observations
of living things
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What observations
can you make about
this cartoon?
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Admin:
• Pass out outline of notes and syllabus
• Go over syllabus
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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This Class is HARD!
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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 way
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 Awareness
and appreciation of life
 Important in decisions of life
 Issues dealing with biology arise daily
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Characteristics of Life
•
What things in this
picture are living?
•
What things are nonliving?
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Characteristics of Life
Bacteria
Is it living?
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Characteristics of all living
things
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What are some characteristics that are
shared by all living things but NOT by nonliving things?
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Characteristics of all living
things
1.
2.
3.
4.
5.
6.
7.
CELLULAR ORGANIZATION
METABOLISM
HOMEOSTASIS
GROWTH
 Today and through
REPRODUCTION
the term, we’ll be
discussing these
HEREDITY
properties of life
EVOLUTION
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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
Humans have organ
and tissue systems
Complex function
 Organization is required
for function
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Even bacteria have
organization
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Characteristics of life
2. 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.
2 - METABOLISM
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Collect energy from their
environment and use it to grow and
develop
Energy of sunlight – Photosynthesis
Energy from other living organisms –
Cellular Respiration
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Metabolism examples
PHOTOSYNTHESIS
MOVEMENT
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Thru Metabolism Life Responds to
the Environment
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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
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Senses often different
than a human’s
 Ultraviolet/infrared
light
 Electrical/ultrasonic fields
 Magnetic fields
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Response to Environment
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Senses often different
than a human’s
 Detection
of chemicals
(flies/insects)
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This response
involves metabolism
and may change the
metabolism of the cell
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Characteristics of life
3.
Homeostasis
Life Actively Maintains its Structure and
its Internal Environment.
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Organisms respond to env changes to keep
their internal operating conditions within
tolerable limits, else they …
3 - HOMEOSTASIS
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Ability of an organism
to keep internal
environment of cell or
organism relatively
constant compared to
outside environment
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HOMEOSTASIS
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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
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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
PLANT CARBON
DIOXIDE - STOMATA
ANIMAL TEMPERATURE
- BEHAVIORS
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4 - Growth and Development
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DNA as a blueprint
 Organisms
grow and propagate themselves
 Organisms develop and grow in complexity
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Growth and Development
(3) Living things grow and
develop
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5 - Reproduction
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Living organisms
reproduce or replicate
themselves
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Reproduction
EGG AND SPERM
POLLEN, FLOWERS,
SEEDS
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6 - Heredity
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Genetic material (DNA) is
passed from parents to
offspring
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7 - Evolve
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Mistakes are made in replicating DNA
Causing the characteristics of a population to
change
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Last 4 Characteristics of life:
4.
5.
6.
7.
Living Things Grow,
Reproduce
Using DNA (Heredity)
and have the Capacity to Change & Evolve
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
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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
Life’s
Hierarchy
Ecosystem
Community
Population
Organism
Brown pelican
Organ system
Organ
Tissue
Atom
Nucleus
Cell
Organelle
Molecule
Biosphere
Ecosystem
Florida coast
Community
All organisms on
the Florida coast
Population
Group of brown
pelicans
Organism
Brown pelican
Life’s
Hierarchy
Organism
Brown pelican
Spinal cord
Nerve
Organ system
Nervous system
Brain
Life’s
Hierarchy
Organ
Brain
Tissue
Nervous tissue
Atom
Cell
Nerve cell
Nucleus
Organelle
Nucleus
Molecule
DNA
Organization of Life
 Atoms
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Smallest unit of elements*
 Molecules
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Smallest unit of compounds*
 Cells
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Smallest unit of life
 Populations
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The unit that changes with time
* Will be discussed in chemistry
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Species vs Population
Population –cats in an
area
Species –all kitty cats
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What’s a species?
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A group of organisms
that can interbreed
and produce fertile
offspring
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Why “fertile offspring”?
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The mule
 horse-donkey
hybrid
 Cannot breed
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Levels of
Classification
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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
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Seven levels
Add Domains for
eight
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Levels of Classification
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How do we classify all these organisms?
Levels of Classification
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How do we classify all these organisms?
Single-celled
prokaryotes
Single-celled
prokaryotes
Single- or
multi-celled
eukaryotes
Classification: The Tree of Life
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The Tree of Life is based on DNA
sequence similarity
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Evolve vs Grow
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EVOLVE: Species
change over
generations
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GROW: Individuals
change over
organism’s lifespan
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Father of Evolution
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Darwin’s Theory of Natural
Selection
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Individuals in a
population vary in
their traits
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Darwin’s Theory of Natural
Selection
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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
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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
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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
Theory of Evolution
explains the diversity
seen in the natural
world
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Review of the Properties of Life
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CELLULAR
ORGANIZATION (or
ORDER)
HOMEOSTASIS or
REGULATION
GROWTH and
DEVELOPMENT
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METABOLISM and/or
RESPONSE TO
ENVIRONMENT
REPRODUCTION
with DNA
HEREDITY (DNA)
EVOLUTION
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-Review of Cells
PLANT CELL
ANIMAL CELL
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-Review of Cells
CELL SIZE COMPARISON
• Animal
• Plant
• Bacteria
• Noncellular
viruses
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SUMMARY
All living things share certain
characteristics
 The differences between living and nonliving 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 nonliving are not clear-cut
 Living things are classified into domains
and kingdoms
 Levels of organization defines biology
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The Scientific Method:
How Scientists Think
Deductive Reasoning
 Makes a decision by
applying a general
principle
Inductive Reasoning
 Makes a general principle
by applying many
different specific
observations
Should I touch this piece of metal?
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Two Approaches to Science
1.
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DISCOVERY SCIENCE
No experiments
Based on observations
Inductive reasoning –
general principles
derived from large
number of specific
observations
EXAMPLE: All living things
are composed of cells
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Two Approaches to Science
1.
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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
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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!
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Pasteur's hypothesis testing of
spontaneous generation.
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The Scientific Method
1. 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
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OBSERVATION: Millions
of fish are periodically
killed in mysterious dieoffs 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
Example
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What is an hypothesis?
A
testable explanation
that explains an
observation
 Addresses the question
which came from the
observation
Hypothesis:
A microscopic protist,
Pfiesteria, was killing
the fish
What is your hypothesis
about the fish die-offs?
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Predictions
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Based on the hypothesis
Can be tested
Example—two testable predictions
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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
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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.
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Experiment
Does Brand X fertilizer really help my plants grow?
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Controlled Experiments Have:
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TWO GROUPS
 Experimental
 Control
group
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 Experiment
Control Group
Experimental Group
INDEPENDENT VARIABLE?
CONSTANTS?
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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
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
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