biology 1020: principles of biology instructor: dr. scott bowling
TRANSCRIPT
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Biology 1020:Principles of Biology
Instructor: Dr. Scott Bowling
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Today’s Lecture Topics
Active learning
Course syllabus / other initial business
Chapter 1: The Science of Biology
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• Groups of 3-4• 1 sheet of paper; answer:
– WHO ARE YOU? (first and last names)– WHY ARE YOU HERE? (in this class)– WHAT DO YOU WANT? (out of this class)
Answers are group answers, not individual – introduce yourselves, list your names, discuss the other two questions, then write group summaries for them.
You have five minutes – begin!
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Chapter 1: The Science of Biology
Scientific MethodCharacteristics of living things Information transfer in living systemsDiversity of Life / classification of living
systemsEnergy flow in living systems
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Chapter 1: The Science of Biology
Scientific MethodCharacteristics of living things Information transfer in living systemsDiversity of Life / classification of living
systemsEnergy flow in living systems
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• Discuss how the scientific method works, and the difference between inductive and deductive reasoning.
• Come up with examples of inductive and deductive reasoning.
• Do NOT worry about learning the scientific method as “step one – step two – etc.”
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• Discuss testable models, including terms for them and why “testable” matters. How does this relate to the supernatural?
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Biology is Studied Using the Scientific Method
Science is based on a systematic thought process
uses deductive and inductive reasoning makes testable models of how the universe
works
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Biology is Studied Using the Scientific Method
deductive reasoning summarize the information at hand draw conclusions from that information proceeds from the general to the specific
inductive reasoning generalization from several specific observations proceeds from the specific to the general must be careful, because it is impossible to prove the
accuracy of the generalization
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Deductive reasoningProceeds from the general to the specific If starting general assumptions are true,
then the conclusion must be trueExample:
All birds have wings.Sparrows are birds.Deduced conclusion would be:
Sparrows have wings.
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Inductive reasoning Drawing a generalization from several specific
observations Proceeds from specific to general Example:
Sparrows are birds, and they have wings. Falcons are birds, and they have wings. In fact, all birds that I have ever seen or heard of
have wings. By inductive reasoning, the conclusion would be:
All birds have wings.
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Inductive reasoning Impossible to prove the accuracy of the
generalizationDespite this shortcoming, it forms basis of
most science
…this is the main reason why science is an unfolding, evolving process
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Biology is Studied Using the Scientific Method
The scientific method in a nutshell: summarize existing observations make a model about how the universe
works (using those observations) test the model revise the model as needed and repeat
(and repeat, and repeat, and repeat….)
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Biology is Studied Using the Scientific Method
summarizing existing observations may also involve collecting new information or observations if there aren’t enough already
then a hypothesis is made; this is a testable model that:
explains the existing observations makes predictions that can be tested often more than one hypothesis is made
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Biology is Studied Using the Scientific Method
More observations are made to test the correctness of the hypothesis; where possible, an experiment is conducted
In an experiment conditions are controlled to provide a better and more reliable test
Experimental or treatment group - the individuals given the specific treatment or condition being tested (may be more than one treatment group)
Control group - the individuals not given the specific treatment (may be more than one control group)
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Biology is Studied Using the Scientific Method
observations and measurements are taken of the experimental and control groups
the data are compared the data should provide evidence to either reject
(disprove) or support (but never prove) the hypothesis
care must be taken that the experimental and control groups receive the same treatments except for the specific effect being tested; avoid things such as the placebo effect
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Analysis of Experiments Experimenter must
interpret the results (often using statistics)
Taking small sample sizes often results in errors in the estimate of the entire population
The larger the sample size, the more reliable the results
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The Scientific Method
Summarize existing observations (and make new ones)
Formulate a hypothesis, a model that:Explains existing observationsMakes testable predictionsCan never be proven true, only supported or
disproved
Test the hypothesis (experiment)
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01.04 Scientific MethodSlide number: 2
Observation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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01.04 Scientific MethodSlide number: 3
Question
Observation
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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01.04 Scientific MethodSlide number: 4
Question
Observation
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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01.04 Scientific MethodSlide number: 5
Question
Observation
Experiment
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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01.04 Scientific MethodSlide number: 6
Question
Observation
Rejecthypotheses1 and 4
Experiment
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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01.04 Scientific MethodSlide number: 7
Question
Observation
Rejecthypotheses1 and 4
Experiment
Hypothesis 5Hypothesis 3Hypothesis 2
Remainingpossiblehypotheses
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
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01.04 Scientific MethodSlide number: 8
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Question
Observation
Rejecthypotheses1 and 4
Experiment
ExperimentHypothesis 5Hypothesis 3Hypothesis 2
Remainingpossiblehypotheses
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
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Rejecthypotheses2 and 3
01.04 Scientific MethodSlide number: 9
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Question
Observation
Rejecthypotheses1 and 4
Experiment
ExperimentHypothesis 5Hypothesis 3Hypothesis 2
Remainingpossiblehypotheses
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
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Rejecthypotheses2 and 3
01.04 Scientific MethodSlide number: 10
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Question
Observation
Rejecthypotheses1 and 4
Experiment
ExperimentHypothesis 5Hypothesis 3Hypothesis 2
Remainingpossiblehypotheses
Last remainingpossible hypothesisHypothesis 5
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
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Rejecthypotheses2 and 3
01.04 Scientific MethodSlide number: 11
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Question
Observation
Rejecthypotheses1 and 4
Experiment
ExperimentHypothesis 5Hypothesis 3Hypothesis 2
Remainingpossiblehypotheses
Last remainingpossible hypothesisHypothesis 5
Predictions
Experiment 1 Experiment 2 Experiment 3 Experiment 4
Predictionsconfirmed
Hypothesis 1Hypothesis 2Hypothesis 3Hypothesis 4Hypothesis 5
Potentialhypotheses
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The Scientific Method
The recursive nature of the process: experiments provide more observations at any time more observations may be added in
and more testable models may be produced …this may in turn lead to more experiments, and
the process continues this generally leads to progress towards more and
more reliable models of how nature works creative thinking often plays a major role when
rapid progress occurs
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Scientific Method
Hypothesis, theory, and law A well supported hypothesis that links together
a large body of observations is considered a theory.
A theory that links together significant bodies of thought and yields unvarying and uniform predictions over a long period of time becomes considered a principle or law.
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• Discuss how the scientific method works, and the difference between inductive and deductive reasoning.
• Come up with examples of inductive and deductive reasoning.
• Do NOT worry about learning the scientific method as “step one – step two – etc.”
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• Discuss testable models, including terms for them and why “testable” matters. How does this relate to the supernatural?
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Scientific Method
caveats: Scientific models can only be proven false, never
proven true. Correlation does not equal causation. Testable predictions cannot include the supernatural
(the supernatural cannot, by definition, be tested scientifically); thus, the supernatural is outside the realm of science.
The term “theory” has a very different meaning in science than in most everyday conversations.
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Scientific Method
science and technology – the goal of science is to understand nature the goal of technology is to apply scientific
knowledge for a specific purpose
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Chapter 1: The Science of Biology
Scientific Method
Characteristics of living things Information transfer in living systems Diversity of Life / classification of living systems Energy flow in living systems
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• Explain the characteristics of living matter to each other. Answer the “Fido” question (will be described in class).
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Characteristics of Living Things Generally, life on Earth is defined such that all
living things… are made up of cells grow & develop regulate their metabolism perceive and respond to stimuli reproduce
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Characteristics of Living Things
All living things are made up of cells The cell is the basic unit of life, both in structure
and function; it is living material bounded by a membrane
Cells come from and give rise to other cells Some organisms are unicellular; some are
multicellular
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Characteristics of Living Things
All living things grow & develop growth - increase in size and/or number of
cells growth may be different in different locations
development – changes in roles of cells during life cycle of an organism individual changes as development proceed
throughout life
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Characteristics of Living ThingsAll living things regulate their metabolism
metabolism - the sum of the chemical reactions and energy transformations that take place within a cell
homeostasis - the tendency of an organism to maintain a relatively constant internal environment
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Characteristics of Living ThingsAll living things perceive and respond to
stimulistimulus - physical or chemical changes in the
internal or external environment of an organismcells “talk” to each other through cell signaling
via special molecules (such as hormones, neurotransmitters)
organisms signal state via behavior
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Characteristics of Living Things
All living things reproduceAll life arises from previous living formsReproduction can be asexual (copying):
Simple – cells merely splitMany unicellular organisms reproduce this wayVariation only by mutation in genes
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Characteristics of Living ThingsAll living things reproduce
Reproduction can be sexual:Sex = genetic recombinationComplex, typically involves fusion of specialized egg
and sperm cells to form a zygote (fertilized egg)Genes provided by parentsProvides for variation in offspring
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• Explain the characteristics of living matter to each other. Answer the “Fido” question (will be described in class).
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What is the primary way that information is transferred from one living generation to the next?
What (in biology) is a Domain?
What are the six kingdoms? (modern classification)
Why is energy important for life?
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Chapter 1: The Science of Biology
Scientific Method Characteristics of living things
Information transfer in living systems
Diversity of Life / classification of living systems Energy flow in living systems
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• Discuss the role of information in life, and how it is dealt with (on the molecular level).
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Organisms Contain an Information System
Information must be transferred from one cell generation to the next
In multicellular organisms, information must also be transferred from one generation to the next
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Organisms Contain an Information System
Cells have an information system made up of nucleic acids – specifically: DNA (deoxyribonucleic acid)
The information is encoded in regions of DNA called genes, the units of heredity
Genes are instructions that use a special, unique code
Instructions are generally for the production of specific proteins
The nucleic acid code is virtually identical in all species
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Organisms Contain an Information System
Organisms pass on their DNA to the next generation
Characteristics of each generation depend upon DNA
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Organisms Contain an Information System
Information is also exchanged between cells
Hormones are chemical signals used for intercellular signaling
Physical signals may also be used for intercellular communication
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• Discuss the role of information in life, and how it is dealt with (on the molecular level).
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Chapter 1: The Science of Biology
Scientific Method Characteristics of living things Information transfer in living systems
Diversity of Life / classification of living systems
Energy flow in living systems
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• Explain the binomial system and taxonomic hierarchy.
• What is a species name?
• What do the two words in a species name represent, and how do you write them?
• How will you memorize the hierarchy?
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The Diversity of Organisms Biologists use a hierarchical binomial system
for classifying organisms. about 1.8 million living species have been
identified, likely millions more
Taxonomy - the science of classifying and naming organisms
Carolus Linnaeus – 18th century Swedish botanist; developed a system of classification that is the basis of what is used today
binomial system because a combination of two names, genus and specific epithet, uniquely identifies each species
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Species - basic unit of classification or taxonomy if sexual, a group of organisms that can interbreed
and produce fertile offspring if asexual, grouped based on similarities (DNA
sequence is best)
Genus - a group of closely related species Species name has two parts (binomial)
Genus and specific epithet (using Latin or Latinized language)
The specific epithet usually describes something about the organism, or is based on the name of the discover
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Species name has two parts (binomial)Genus name is always capitalizedspecific epithet is never capitalizedThe complete species name is always
italicized (or underlined)Example: Homo sapiens or Homo sapiensMay abbreviate genus name if used
already and context is clear: H. sapiens
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Taxonomic classification is hierarchical
• A group of related genera make up a Family• Related families make up an Order• Related orders Class• Related classes Phylum or Division• Related phyla or divisions Kingdom• Related kingdoms Domain, the highest level of
classification in the modern system.
The gold standard for “related” is based on DNA sequence similarities, but other criteria are used as well (we don’t have the complete DNA sequence of all known species)
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Taxonomic classification is hierarchical
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Dashing King Philip came over for great…
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• Explain the binomial system and taxonomic hierarchy.
• What is a species name?
• What do the two words in a species name represent, and how do you write them?
• How will you memorize the hierarchy?
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• What are the three domains and six kingdoms?
• How do you decide which kingdom to put a eukaryote into?
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The most widely accepted classification
system today includesthree domains and six kingdoms
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Two domains consist of prokaryotes, organisms with no true cellular nucleus
Domain Archaea – Kingdom Archaebacteria bacteria typically found in extreme environments distinguished from other bacteria mainly by ribosomal
RNA sequence include methanogens, extreme halophiles, and
extreme thermophiles
Domain Bacteria – Kingdom Eubacteria very diverse group of bacteria examples: blue-green algae, Escherichia coli
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Domain Eukaryaeukaryotes, organisms with a discrete cellular
nucleus; divided into four kingdoms
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Domain EukaryaProtista
Single celled and simple multicellular organisms having nuclei
includes protozoa, algae, water molds, and slime molds
“lump group” for eukaryotes that do not fit in the other 3 kingdoms within eukarya
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Domain EukaryaProtista
NOTE: This kingdom is likely on the way out, to be replaced by several kingdoms based on genetic/evolutionary relationships instead
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Domain EukaryaFungi
organisms with cell walls consisting of chitinmostly multicellular, multi-tissuedincludes molds, yeasts, mushroomsmostly decomposers
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Domain Eukarya (cont.) Plantae (plants)
complex multicellular organisms having tissues and organs
Plant cells have walls containing cellulose most contain chlorophyll in chloroplasts, and carry
on the process of photosynthesis Nonvascular (mosses) and vascular (ferns, conifers,
flowering plants) Mostly producers
NOTE: kingdom is being replaced by Viridiplantae, which includes green algae
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Domain Eukarya (cont.) Plantae (plants)
complex multicellular organisms having tissues and organs
Plant cells have walls containing cellulose most contain chlorophyll in chloroplasts, and carry
on the process of photosynthesis Nonvascular (mosses) and vascular (ferns, conifers,
flowering plants) Mostly producers
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Domain Eukarya (cont.) Plantae (plants)
NOTE: kingdom is being replaced by Viridiplantae, which includes green algae
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Domain Eukarya (cont.)Animalia (animals)
Complex multicellular organisms that depend on other organisms for nourishment
Cells lack wallsTypically have organs and organ
systemsMost forms are motile
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• What are the three domains and six kingdoms?
• How do you decide which kingdom to put a eukaryote into?
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Chapter 1: The Science of Biology
Scientific MethodCharacteristics of living things Information transfer in living systemsDiversity of Life / classification of living
systems
Energy flow in living systems
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• What is the importance of energy in living systems?
• What are autotrophs and heterotrophs?
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Life Depends on a Continuous Input of Energy
All life depends upon energy
Original source mostly the sun
Energy flows through cells, organisms
Energy flows through ecosystems (the concept of a food chain or food web)
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Energy is used: To maintain existing cellular structures and
components (replacement of damaged or worn out materials within the cell)
To produce materials to support growth, development, and reproduction
To support: movement, either of cell itself or of materials into
and out of the cell signaling responses, such as hormone production
and perception, nerve impulses, etc. other forms of cell work, such as symbiotic
relationships with other organisms, defense against pathogens
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Producers (autotrophs) manufacture their own food from simple materialsusually produce food by the process of
photosynthesis:
Carbon dioxide + Water + light energy ───> Carbohydrate (food) + Oxygen
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Energy is released from food mostly by oxidative respiration
Carbohydrate (food) + Oxygen ───> Carbon dioxide + Water + energy
overall, producers use carbon dioxide and water and release food and oxygen
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Consumers (heterotrophs) obtain energy by eating other organisms
ultimate source of food is producersuse food and oxygen, and release carbon
dioxide and water
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Decomposers obtain energy by breaking down the waste products, by products, and dead bodies of producers and consumersStill heterotrophs (ultimate source of food
is producers)Decomposition recycles nutrients from
dead bodies back to living ones; without decomposers, living systems would starve for energy
Decomposers are usually bacteria and fungi
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• What is the importance of energy in living systems?
• What are autotrophs and heterotrophs?
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Themes learning biology is not just learning a set
of facts and concepts; you need to organize that information
watch for the recurrence of certain themes that come up repeatedly in biology (major examples on next slides)
in addition, an awareness of the process of scientific inquiry and the application of science (technology) are important aspects of any study of biology
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Themes The cell Information management
heritable information regulation interaction with the environment
Energy management Structure and function Unity and diversity Emergent properties Evolution – the core unifying theme that explains
much of the observations connected with the other themes