Using the scientific method biologists have discovered patterns in the living world that explain both its unity and diversity 1 Unit 1 Key learning The unity and diversity of life indicate that all living things evolved from common ancestry ID: 783112
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Slide1
Biology is a Discipline of Science
Using the scientific method, biologists have discovered patterns in the living world that explain both its unity and diversity.
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Slide2Unit 1: Key learning
The unity and diversity of life indicate that all living things evolved from common ancestry.The scientific method is a systematic approach to problem solving that increases the speed at which discoveries are made & allows scientists to have confidence in the theories that are generated.
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Slide3Unit 1: Essential question
How do scientists use the scientific method to establish theories and laws in Biology?
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Slide4What is Life?In order to study life, we first have to define what life actually is…
Read the “Preview:” section on page 3 of your unit guide. Work with your partner to come up with your best definition of life and write it in the space at the bottom of page 3.
4UG – Page 3(Cross out question #1 on page 3 & question #2 on page 4 of your unit guide)
Slide5Launch activity:
Working collaboratively (???) with your partner, write a list of at least 2 reasons why each object should be considered a living organism and 1 reason why it shouldn’t.
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UG – Page 4
Slide6Launch summary:
Living things can be identified as being separate and different from non-living things using a specific set of shared characteristics.
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Slide7Unit 1: Concepts
The Unity and Diversity of Life (I)The Scientific Method (E)
Scientific Theories (E)
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Slide88
Essential questions 1.1 & 1.2:
What characteristics are shared by all living things? (
Unity
)2. Why do all living things share these characteristics, but differ in other ways? (
Diversity)
Slide9Question:
What are some of the major groups (
kingdoms) that biologists can use to divide living organisms?
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Animalia
Bacteria
Protista
Fungi
Plantae
Archaea
UG – Page 4
Slide10Kingdoms continued
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All organisms that are placed into a kingdom share common characteristics with all other members of that kingdom.Organisms from different kingdoms generally differ greatly from one another.
Slide11Despite being diverse in appearance, Earth’s organisms share 6 common characteristics.
All forms of life (simple or complex) must satisfy a few basic needs in order to survive.
The better an organism is at satisfying these needs, the more likely it is to survive and reproduce.
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UG – Page 5
Slide12Six characteristics unify the diversity of living things.
Cellular organization
MetabolismHomeostasisGrowth and developmentResponse to stimuliHeredity
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Slide131. Cellular organization
(the cell theory)All organisms are composed of one or more cells.All cells arise from pre-existing cells.Cells are the smallest unit of structure and function; in other words, the smallest structure considered to be alive.Each cell has a specific form that helps it to perform specific tasks.The activities of cells are controlled by information stored in their genes.
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Q #1 –
Page
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Slide14Question:
Does
form determine function, or does function dictate form?This concept will be continually explored over the course of this unit and again as we deal with these topics in depth in later units. Generally speaking…If you change the form of something you change its functionality or its ability to function within the body.
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Q #2
– Page
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Slide152. Metabolism
C
hemical reactions are necessary for organisms to obtain or use energy.Energy is necessary to sustain life.All energy enters the biosphere when producers use photosynthesis or chemosynthesis to store energy.Some organisms called consumers can only obtain energy by ingesting other organisms.
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Q #3-5
– Page
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Slide16Question:
What are 3 living organisms that you would call biological producers?
What are 3 living organisms that you would call biological consumers?
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Slide17Class Starter:17
Talk to your partner to answer the following without looking at your notes:List the 6 characteristics shared by all living things.
Slide183. Homeostasis
Homeostasis is the maintenance of a steady internal environment in response to a changing external environment.
All living things must maintain a stable and consistent internal environment in order to effectively conduct their metabolism.
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Slide19Question:
What types of things does your body do to maintain homeostasis?
Pressure sensations cause you to release solid and liquid wastes.Hunger sensations cause you to eat.Dry mouth sensations cause you to drink.
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Individual cells also must regulate their internal environments in response to chemical cues and imbalances.
Q #6
– Page
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Slide204. Growth and development
All organisms begin life as a single cell.
Multicellular organisms increase their size through a growth process driven by cell division.As cells divide, they may take on specialized functions during the process of development (zygote-embryo-infant-adolescent-adult).
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Q #7
– Page 7
Slide21Question:
How is fetal development different than development once a human is born?
Fetal development is a much more drastic metamorphosis, with tissues (muscle, nervous, etc.) being formed from undifferentiated cells, while development after birth is more cognitive (our ability to understand our world).In order for cells to correctly differentiate and take on their proper functions, development must not be affected by chemical mutagens such as drugs, alcohol or caffeine.
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Q #8
– Page 7
Slide22Question:
Why does your body feel pain?The perception of pain helps your body to avoid those things that might cause bodily harm.
We can also assume that fear is necessary to help us avoid potential pain that may result from our actions.Ironically, organisms in a natural setting that are most likely to act against their fears, have the most to lose and the most to gain!
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Q #9
– Page 7
Slide235. Responsiveness to stimuli
Organisms must respond to the world around them, in order to:
find food, locate shelter, find mates, Escape from danger.Cells may not have the complex sensory abilities of multicellular organisms, but they must still perceive the environment around them in order to maintain homeostasis (open and close gates, communicate with other cells).
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Slide246.
Heredity
Reproduction keeps a species alive, since no individual lives forever.Information is passed from one generation to the next (heredity) and defines the characteristics of that generation.This passage of information from generation to generation is the reason
why evolution occurs.
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Q #10-11
– Page 7
Slide25Going Further: Heredity and evolution
Genes store information regarding the structure of specific proteins.
Genetic information is stored in a molecule called DNA.Changes in the DNA of a gene are called mutations, and lead to variations in organisms (blue or brown eyes).The differing success of these variations is called natural selection. Natural selection occurs when organisms with favorable characteristics survive and reproduce- this is just one mechanism for evolution.
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Q #12
– Page
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Slide26Summarizing:
Suppose you find an object that looks like an organism. How might you determine if your discovery is indeed alive?
You would look for evidence of…Cellular structure and functionMetabolismHeredityGrowth and developmentHomeostasisResponsiveness to stimuli
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Summarize
– Page
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Slide27ReviewHow do the 6 characteristics that all living organisms share unify the diversity of life?Cellular Organization
MetabolismHomeostasisGrowth & DevelopmentResponse to stimuliHeredity
27All living things, no matter how different from each other, must perform all 6 characteristics to be considered a living organism.
Review
– Page
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Slide28Unit 1: Concepts
The unity and diversity of life (I)The scientific method (E)Scientific theories(E)
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Slide2929
Essential question
2.1
:
What steps must be taken to ensure a proper application of the scientific method?
Slide30Scientific method basics…
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Slide31The Scientific method is a systematic approach to problem solving.
Steps required in using the Scientific Method
Generate questionsConduct background research Develop a hypothesis and make predictionsDevise an experiment to test the prediction Conduct the experiment and analyze data Draw conclusions based on observed dataRepeat the tests or devise new ones
Submit results and conclusions for publication
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Give one – Get one
Slide32Scientific Method
It is expected that you know the steps of the scientific method from your earlier science classes. If you aren’t confident in your knowledge of it, use the unit guide to refresh your memory.Lab Time!!!32
Slide33Questions that do not deal with the physical world are un-testable.
Questions may arise in many ways:
Human curiosity, such as “How did the universe form?”Human need, such as “How can we prevent cancer from killing a patient?”Questions may arise during a different scientific investigation and be reported in scientific papers as avenues for future study.The question will appear in the “Introduction” section of a scientific paper.
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1.
Generate questions
about objects, organisms and/or events that can be answered through scientific investigations (i.e. natural as opposed to supernatural phenomenon).
Slide34Scientific journals provide peer reviewed resources documenting the conclusions of past investigations.
Continued observations may yield a deeper understanding of the question / problem.
A pilot study may be undertaken to provide for a deeper understanding of a problem.The “Introduction” section of a scientific paper will include any research necessary to provide a context (understanding) for the question / problem.
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2.
Conduct
background research
in order to understand the context of the problem
(e.g. literature search, continued observation, limited experimentation, etc.
).
Slide35Hypotheses
are “educated” guesses since they are based upon background research.A
hypothesis such as “I believe that the more active a body is, the greater the breathing rate will be,” allows a researcher to develop a prediction such as, “If I put a man on treadmill, then his breathing rate should rise above its resting level.”The hypothesis will appear in the “Introduction” section of a scientific paper.
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3. Develop a
hypothesis
(educated guess)
and use it to make predictions that follow the “
if-then
” process.
Slide36Experiments should be well controlled and represent the smallest departure from the natural state of a system.
One
variable (the independent variable) should be tested at a time, in anticipation of a change in the dependent variable.By testing one variable at a time, a scientist can determine whether altering that variable produced the desired result.The experimental design will appear in the “Methods” section of a scientific paper.
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4. Devise a way to test the prediction
(i.e. making systematic observations, constructing theoretical models, conducting experiments).
Slide37Data should be collected in tables and analyzed using graphs and other statistical analysis techniques designed to determine the reliability of trends.
Trends observed in large data sets are more reliable than those seen in smaller sets.
The analysis techniques that were employed will appear in the “Methods” section of a scientific paper while the tables and figures will appear in the “Results” section.
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5
. Conduct the test and
analyze experimental data
using a variety of statistical methods.
Slide38Many investigations will not support the hypothesis but do offer a researcher the ability to eliminate a possibility.Very often the experimental design is flawed in such a way as to cause a researcher to redesign the experiment.
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6.
Draw conclusions
based on observed data; in other words, did the experiment support or refute the hypothesis.
Slide39If the test was not flawed and did support the hypothesis, repetition should be completed; time, money and availability of subjects / specimens will determine how much repetition is acceptable.
If a test was flawed, the researcher will need to redesign the experiment to address the errors and again assess the ability of the investigation to answer the question at hand.
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7.
Repeat the tests
or devise new ones that address experimental error or faulty design
Slide40Once conclusions are made, a researcher must submit their work to a peer reviewed journal to be evaluated prior to publication.
Published journals will provide other researchers in the field access to the conclusions made and allow them to advance their own research.
The data used to make conclusions will appear in a the “Results” section of a scientific paper while the conclusions and other related details will appear in the “Discussion” section of a scientific paper.
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8. Submit results and conclusions for
publication
with suggestions made for additional steps that might be done experimentally.
Slide41Question:
What are some problems that science might seek to solve?
How does a new drug affect the growth of cancer?How has a population fluctuated as a result of environmental distress?Science can not address questions that are supernatural such as “Did God create the Earth?”Questions such as this are valid but not of a scientific nature.
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Slide42Scientists use common speech and measurements to make their results understandable to people all around the world.
Scientific terminology is written in latin in order to keep it consistent within each language.Felis concolor rather than Mountain LionMeasurements are made using metric units so that scientists are all using a common system.1 kilogram rather than 2.2 poundsThe
results of scientific experimentation are reported using a refereed system of scientific papers.Each paper reports specific information in a standard fashion.
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Slide43The variable to be tested is compared to a control group.
Only one idea at a time should be tested (
variable).The control group receives no experimental treatment and closely approximates reality.The results of the variable can be compared to the control to see if a change occurred.
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Slide44There are actually two variables in each experiment.
The manipulated variable
(independent) is the one factor that is changed.A variable group exercises 3 days a week, while a control group maintains their normal routine.The responding variable (dependent) is what you expect to change in response to your “tinkering”.The variable group loses weight, while the control group maintains their normal weight.
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Slide45Question:
How can we measure the affect of exercise on the rate of breathing?
Generate question- completed!Conduct background research Develop a hypothesis and make predictionsDevise an experiment to test the prediction Conduct the experiment and analyze data Draw conclusions based on observed dataRepeat the tests or devise new onesSubmit results and conclusions for publication
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Slide46Question: What was the
manipulated (independent) variable in our experiment?
The amount of activity was the manipulated variable since it’s what we altered.The rate of breathing was the responding variable (dependent) since it’s what we measured to see if there was a change.The rate of breathing “responded to” the amount of activity.
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Slide47Bubble-ology LabRead the introduction and complete the Pre-lab portion of the bubble-ology lab packet.
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Slide48Scientific writing is presented using a standardized journal format that allows readers to find evidence of each of the part of the scientific
method.The MASD science faculty have compiled a manual to aid you in the process of writing scientific papers- keep it for the entire year!
In Biology class, we will write each of the sections of a scientific paper after an appropriate lab activity.In addition to the specifics of scientific paper formatting, we expect you to write with attention paid to proper grammar and spelling.
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Slide4949
Slide50Unit 1: Concepts
The unity and diversity of life (I)The scientific method (E)Scientific theories(E)
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Slide5151
Essential question
3.1
:
How does an idea become a scientific theory?
Slide52Stop and Read Handout the article – “Problems with Vocabulary, Science and
Culture”Jigsaw – Form groups of THREE (no more…no less) and wait for further instructions.
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Slide53ARTICLE SUMMARY STATEMENT
The author uses the evolutionary theory to exemplify the difference between the technical and everyday use of the term “theory.”
This is similar to the misuse of the terms idiot (adult with a mental age of 3 or less) and moron (adult with mental age of 8-12).
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Slide54Hypothesis, theories, and laws represent differing degrees of certainty within the scientific world.
A hypothesis
is an educated guess, and must be tested scientifically before it is confirmed or rejected.A theory is our best explanation for a large number of observations. In order to survive, it must stand the test of time, and repeatedly produce accurate hypothesis.In order to be scientific, a theory must be falsifiable.A law is a directly observable and predictive explanation for how the physical universe will behave under certain conditions.Generally explained by an equation.
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Slide55Question:
What are some current scientific theories that you’ve heard of?The Big bang theory
(not the TV show)The Theory of evolutionThe Theory of plate tectonics
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Slide56The study of biology requires knowledge of theories from many fields of science.
Earth science
: Plate tectonics, climate change and the study of the chemical / physical properties of the Earth.Chemistry: Atomic theory and the study of the properties of atoms, elements and compounds.Physics: The study of matter and energy.
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Slide57Biologists help solve the world’s problems by applying knowledge from our many theories.
Biologists help to…
Prevent destruction of the world’s ecosystemsRainforests provide food sources and potential medicines.Feed the growing global populationGenetically engineered crops provide a greater yield, while requiring less pesticides and fertilizer.Cure disease e.g. cystic fibrosis, AIDS and cancer.Gene therapy and pharmaceuticals.
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