Introduction to Biological Science

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Introduction to Biological Science

• Using the scientific method, biologists have
  discovered patterns in the living world that
  explain both its unity and diversity.

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Unit 1 Key learnings

• The unity and diversity of life indicate that all
  living things evolved from a common ancestor.
• Scientists approach their problems by applying a
  systematic approach called the Scientific method.
• Scientific theories are essentially facts.

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Unit 1 Essential question

• Why are scientists so confident about the
  accuracy of scientific theories?

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Launch 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 shouldnt.

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Launch summary

• Living things can be told apart from other
  objects by the presence of 7 specific
  characteristics.

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Unit 1 Concepts

• The unity and diversity of life
• The scientific method
• Scientific theories

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Essential questions 1-2

• What characteristics are shared by all living
  things?
• 2. Why do all living things share these
  characteristics, but differ in other ways?

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I. Despite being diverse in appearance, Earths
organisms share 7 common characteristics.

• All forms of life (simple or complex) need to
  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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Question What are some of the major groups
(kingdoms) that living things are divided into?

• Animals
• Plants
• Bacteria (Eubacteria and Archaebacteria)
• Fungi
• Protists
• Organisms are placed into these groups because of
  common structures. To a biologist, common
  structures indicate a descent from the same
  ancestors.

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II. Seven characteristics unify the diversity of
living things.

• Cellular organization
• Metabolism
• Reproduction and heredity
• Growth and development
• Homeostasis
• Adaptation
• Responsiveness to stimuli

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II./1. 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.
• Cell structures have forms that help them to do
  their jobs.
• The activities of cells are controlled by
  information stored in their genes.

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Question 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 units to come.

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2. Metabolism

• Many chemical reactions are necessary for
  organisms to obtain and 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 obtain energy by
  eating other organisms.

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Question Which kingdoms contain organisms that
are producers and which contain consumers?
A. Plants B. Algae and other Protists C. Bacteria
Producers
A. Animals B. Bacteria C. Protists D. Plants E.
Fungi
Consumers
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3. Reproduction and 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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Going 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 the mechanism for evolution.

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4. 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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Question 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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5. 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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Question 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.

Cells must also regulate their environments in
response to cues like these.
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6. Adaptation

• Organisms depend on each other and the
  environment in many ways.
• Ecology is the study of the interactions between
  living things with each other and with the
  environment around them.
• Since environments and their communities are
  constantly fluctuating, species often match these
  changes through the process of adaptation.

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Question Why is it that a species may adapt, but
an individual organism cannot?

• Individual organisms are defined by their genetic
  coding, while species are defined by the
  collection of genes (gene pool) within all
  members.
• Natural selection can shape the gene pool and
  cause major changes within a species over the
  course of many generations, while individuals are
  only able to improve within the limits of their
  genetic coding.

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7. Responsiveness to stimuli

• Organisms must respond to the world around them,
  in order to
• find food,
• locate shelter,
• find mates,
• or even 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 (find food, run from danger,
  communicate with other cells).

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Question 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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Question 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 function
• Metabolism
• Reproduction and heredity
• Life span (growth and development)
• Homeostasis
• Adaptation
• Responsiveness to stimuli

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Unit 1 Concepts

• The unity and diversity of life
• The scientific method
• Scientific theories

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Essential question 3
What steps must be taken to ensure a proper
application of the scientific method?
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Scientific method basics
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III. The Scientific method is a systematic
approach to problem solving.

• Steps required in using the Scientific Method
• Generate questions
• Conduct background research
• Develop a hypothesis and make predictions
• Devise an experiment to test the prediction
• Conduct the experiment and analyze data
• Judge the significance of the experimental
  information in answering the questions
• Repeat the tests or devise new ones
• Submit results and conclusions for publication

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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).

• Questions 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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2. Conduct background research in order to
understand the context of the problem (e.g.
literature search, continued observation, limited
experimentation, etc.).

• Scientific 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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3. Develop a hypothesis (educated guess) and use
it to make predictions that follow the if-then
process.

• Hypotheses 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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4. Devise a way to test the prediction (i.e.
making systematic observations, constructing
theoretical models, conducting experiments).

• Experiments 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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5. Conduct the test and analyze experimental data
using a variety of statistical methods.

• Data 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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6. Judge the significance of the experimental
information in answering the questions in other
words, did the experiment support or refute the
hypothesis.

• Many 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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7. Repeat the tests or devise new ones that
address experimental error or faulty design

• If 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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8. Submit results and conclusions for publication
with suggestions made for additional steps that
might be done experimentally.

• Once 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.
• Researchers will often make hypothesis during the
  presentation of their conclusions and suggest
  additional steps that might be taken to continue
  their work.
• 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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Question 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?

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IV. The 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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Science in the news segment- Frog Pollution
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V. There are actually two variables in each
experiment.

• The independent variable is the one factor that
  is changed.
• A variable group exercises 3 days a week, while a
  control group maintains their normal routine.
• The dependent variable 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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4. Scientists 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 Lion
• Measurements are made using metric units so that
  scientists are all using a common system.
• 1 kilogram rather than 2.2 pounds
• The 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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Question How can we measure the affect of
exercise on the rate of breathing?

• Generate question- completed!
• Conduct background research
• Develop a hypothesis and make predictions
• Devise a way to test the prediction
• Conduct the test and analyze experimental data
• Judge the significance of the experimental
  information in answering the questions
• Repeat the tests or devise new ones
• Submit results and conclusions for publication

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Question What was the independent variable in
our experiment?

• The amount of activity was the independent
  variable since its what we altered.
• The rate of breathing was the dependant variable
  since its what we measured to see if there was a
  change.
• The rate of breathing depended on the amount of
  activity.

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VI. Scientific 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 if forever!
• 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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Unit 1 Concepts

• The unity and diversity of life
• The scientific method
• Scientific theories

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Essential question 4
How does an idea become a scientific theory?
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ARTICLE 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 (mental age of 8-12).

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Stephen Jay Gould on the topic of evolutionary
theory

• evolution is as well documented as any
  phenomenon in science, as strongly as the earths
  revolution around the sun rather than vice versa.
  In this sense, we can call evolution a fact.
  (Science does not deal in certainty, so fact
  can only mean a proposition affirmed to such a
  high degree that it would be perverse to withhold
  ones provisional assent.)

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VI. Hypothesis, laws and theories 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 explanation for
  how the physical universe will behave under
  certain conditions.
• Generally explained by an equation.

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Question What are some current scientific
theories that youve heard of?

• The big bang theory
• The theory of evolution
• The theory of plate tectonics

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VII. The study of biology requires knowledge from
many fields of science.

• Earth science the study of the chemical and
  physical properties of the Earth.
• Chemistry the study of the properties of atoms,
  elements and compounds.
• Physics the study of matter and energy.

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Question How can biologists help solve the
worlds problems?

• Biologists help to
• Prevent destruction of the worlds ecosystems,
• Rainforests provide food sources and potential
  medicines.
• Feed the growing population,
• Genetically engineered crops provide a greater
  yield, while requiring less pesticides and
  fertilizer.
• Cure diseases like cystic fibrosis, AIDS and
  cancer.
• Gene therapy and pharmaceuticals.

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Genetically Modified Organisms (GMOs)- corn
RR- Round Up Ready Corn is developed with a
resistance to the herbicide called Round Up.
Bt Corn contains genes from Bacillus
thuringiensis