UNIT 1 – Science of Biology

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• UNIT 1 Science of Biology
• NOTES
• Fill in packet during discussion.
• Be ready to make concept and vocabulary list.

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Topic 1A Characteristics of Living Things
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BIOLOGY The study of life Living things are
known as organisms. The living world and the
non-living world are mixed. As you look out the
window here at school or as you investigate any
environment you will find a mixture of the two.
How can we identify something as an organism?
For each of the items listed below state a reason
that makes it living or non-living
Clouds
Mushrooms
Fire
Automobile
Worm
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What characteristics do all living things share?
1. Living things are made up of units called
cells

• Some organisms are made of only one cell and some
  are made of trillions of cells.
• Cells are small self-contained units of living
  material that are separated from the surroundings
  by a barrier.

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Unicellular organism made of only one cell
Multicellular organism made of more than one
cell. In complex multicellular organisms such
as humans, many different types of cells work
together to perform the functions needed by the
organism.
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• Living things reproduce
• Reproduction is the life process that provides
  for continuation of the species. An individual
  will not die if it does not reproduce but the
  species will end if no members reproduce.

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Terms to know Sexual reproduction- requires
cells from 2 parents to create a new individual
different from each parent. Common in
multicellular organisms (trees, birds
etc.) Asexual reproduction requires only one
parent. Offspring is identical to parent.
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• The traits of living things are determined by the
  genetic code
• When organisms reproduce they pass on genetic
  information in the form of DNA to the offspring.
  
• In sexually reproducing organisms the offspring
  obtain a mixture of genetic information from each
  parent.
• In asexually reproducing organism the offspring
  have identical genetic information to the parent

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• Living things grow and develop.
• Every organism has its own life-cycle a
  pattern of growth and change that occurs over the
  organisms lifetime.

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• Living things obtain and use materials and
  energy.
• Examples
• Oxygen and sugar are needed by organisms to make
  energy.
• Food is needed to help build the body

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Chemical reactions take place in the body to
convert the materials from the environment into
forms usable by the organism. Metabolism is the
collection of all the reaction that take place
within an organism.

• Examples of Metabolic Reactions
• Building Cells
• Breaking down cells
• Converting oxygen and glucose to energy and
  carbon dioxide.

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6. Living things respond to their environment.
Organisms live in a constantly changing
environment. Examples Light, temperature
and amount of water change from day to day and
season to season. Plants and animals must
respond to these changes or they will die.
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7. Living things maintain and a stable internal
environment. The steady state (balance) inside an
organisms body is known as HOMEOSTASIS. While
the environment outside changes an organism must
be able to keep conditions inside mostly the
constant. If homeostasis is disturbed the
organism will become sick and will die if the
balance is not fixed.
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8. Taken as a group, living things change over
time
Life has changed significantly over the history
of the earth. The process of this change is
known as evolution.
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CHECK YOUR UNDERSTANDING 1 (Complete in Chapter
Summary Packet) In essay format discuss what
characteristics all living things have in common
and how life on earth is different. Be sure to
include the following terms in your response in a
way that demonstrates an understanding of the
term Organism, unicellular, multi-cellular,
sexual reproduction, asexual reproduction, life
cycle, metabolism, homeostasis, evolution
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Sample Essay
Living things (organisms) can be distinguished
from non living things by several characteristics
and abilities. All organisms are comprised of
cells. Whether organisms are made up of a single
cell (unicellular) or many cells (multicellular)
they are able to carry out similar processes.
To continue the species all organisms must be
able to reproduce. Some species reproduce by
combining genes from two parents in a process
known as sexual reproduction. Some species
reproduce asexually and produce a genetically
identical offspring. All organisms carry on
chemical reactions in their body, called
metabolism, that allow them to maintain a state
of homeostasis or internal balance. Over time,
life on earth has evolved to include these common
characteristics, but life has developed many
different ways of accomplishing these processes.
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Topic 1B The Scientific Process
What is Science?
Science comes from a Latin word which means to
know
Therefore, Science is a way of knowing. It is
what we use to answer a question about the
natural world
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Science is all about inquiry. People ask
questions about nature and what they observe and
then actively seek to find answers.
The process of finding answers is known as the
Scientific Method.
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The scientific method has brought us the
technology we enjoy today.
These inventions are not the result of any one
discovery but the total knowledge collected over
centuries of scientific inquiry.
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The steps of the Scientific Method?
1-Define the problem (Whats the Question) What
are you trying to find out? What just
happened? Why does it do that?
HUH?
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Write 2 questions about the natural world which
you have wondered about? Examples of questions
Why do pigeons bob their heads when they walk?
Why do leaves turn color in the fall?
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2-Formulate a Hypothesis Hypothesis- A possible
explanation for an observation that can be
tested. Example Pigeons bob their heads
because it helps them see better.
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3-Testing the Hypothesis- Experimentation Finding
a procedure to either verify or disprove the
hypothesis Hypothesis is accepted only when
predicted effects are observed and repeatable
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• A. Experiment design is critical to make
  experiment and hypothesis accepted
• Controlled Experiment- Situation is set up more
  than once to test your hypothesis
• Variable- A single factor in the experiment is
  changed to see if this has an effect on the
  results
• Control group- One group in the experiment where
  no change is made.

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• Characteristics of a well designed experiment
• The sample size is large enough to draw a valid
  conclusion about the hypothesis
• Only one significant variable is tested through
  the experiment.
• A control group is present
• Conclusions must be based on measurable
  quantities or clear criteria and not subject to
  opinion of the observer.

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The dependent variable is the one that changes is
response to the other variable. The independent
variable is the one that causes the change the
other variable.
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In investigating questions where one factor
(variable) is dependent on another, phrase the
tests as The effect of ___________________ on
___________________________. Or __________________
____________ depends on _____________________
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Example The effect of rain amount on oak tree
growth. The growth of the tree depends on the
amount of rain. Therefore we call the growth of
the tree the dependent variable and the amount of
rain the independent variable.
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In the relationships below circle the dependent
variable and underline the independent variable.
(look for things that can be measured)
1. People gain weight based on the amount of
calories they take in.
2. The amount of sunlight available influences
how fast a tomato will ripen.
3. The amount of television watched by children
impacts attention span
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In general the dependent variable is plotted on
the y-axis and the independent variable is
plotted on the x-axis. Example Hypothesis
The more time a student spends thinking before
blurting out, the less time they spend in the
Assistant Principals office. Fill in the
dependent and independent variables on the axes
below
Time in AP office
Time spent thinking before speaking
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B. Measuring Variables
i. International System Units
Meter
Ruler
Gram
Balance/Scale
Liter
Graduated Cylinder
Seconds
Stop Watches
Celsius or Kelvin
Thermometer
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ii. The Scale of Biology
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• For each of the following organisms listed below
  choose the appropriate scale of measurement
  (metric) for scientists to use
• Weight of an Elephant __________________
• Width of a Bacteria _____________________
• Temperature of a liquid ________________
• Length of a feather ___________________
• Weight of a feather ___________________
• Height of a person ____________________

Kilograms
Micrometers
Celsius or Kelvin
Centimeters
Grams
Meters
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• 4-Analyzing and Drawing Conclusions
• Looking at data obtained in the experiment-
• (Use graphs, charts, pie graphs etc.)
• II. Looking for patterns or relationships
• Draw a conclusion about your data
• (Does the data support your hypothesis or not)

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5-Reporting Observations- Record your data and
report in detail your means experimentation and
observed results
Scientists must report all the details because
the experiment has to be repeatable.
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Practice Graph Problems
A. Baby chicks require a constant source of
food. As chicks grow, more energy is required
for daily activities. The following table gives
the grams of food eaten by a chick over a five
day period.
Graph in packet
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A water plant placed in bright light gives off
bubbles of oxygen. In the lab, it was noticed
that if the light were placed at different
distances from the plant in the aquarium, the
rate of bubbling varied. Plot a graph of the
following data.
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6. Tying Discoveries Together
A. Theories and Laws Theory-Explanations that
apply to a broad range of phenomena and that are
supported by experimental evidence Scientific
Law- Statement that describes some aspect of a
phenomenon that is always true
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How do you tell the difference between a
Scientific Theory and Scientific Law?

• A Scientific Law relates to a single action
• Example Gravity
• A Theory explains a series of related phenomena
• Example Evolution
• Cell Theory

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• Both theories and laws are well tested and widely
  accepted.
• Parts of theories can be adapted to new
  discoveries or to make them more understood, but
  the overall theory will not change.
• Laws are not flexible but can be put into
  simpler words.

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• Laws and Theories are different then Hypotheses.
  
• Laws and theories are well tested by
  experimentation.
• Hypotheses are educated guesses based on an
  observation before they are tested.

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Remember All Hypotheses are Valuable Even if a
hypothesis (testable guess) is false it is a
valuable tool because it may lead to further
investigations.
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Topic 1C Laboratory Techniques A. Main
Techniques used in Biology   1.Centrifugation Mat
erials of different densities suspended in a
liquid can be separated by spinning a tube at
high speeds   2. Micro dissection Tiny
instruments that work on one cell at a time
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3. Tissue Culture Maintaining living cells of
tissues outside the body (in vitro)
4. Chromatography A technique that separates
different substances from each other on the
basis of chemical or physical properties 
5. Electrophoresis A technique that separates
proteins, nucleic acids(DNA), and other
substances with an electric current
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6. Spectrophotometry Using light to analyze
what a substance is and how much is
present.
Photo means -
Light

• Staining
• A technique in which a dye is added to make
  a substance within a cell easier to observe.

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8. Microscopy
The microscope is perhaps the most important tool
in the history of biology. The invention of the
microscope opened up the worlds of cells to
scientists. The two types of microscopes used
in this class are compound microscopes and
dissecting microscopes.
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Important Microscope Vocabulary
Magnification enlargement of an object 100X
means that the image appears 100 times bigger
than the actual object.
Resolution the ability of a microscope to show
detail (clarity, sharpness).
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Compound light microscope The compound light
microscope brings light to your eye through a
combination of lenses that allow you to see small
Micro sized objects in a magnified form.
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To determine magnification you multiply the power
of each lens used.
4 (objective) X 10 (eyepiece) 40 magnification
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The best compound microscopes can reach a
magnification of about 2000X. Compound light
microscopes require light to work. The objects
observed in a compound microscope must be thin
enough for light to pass through.
4 x 10 40X
10 x 10 40X
10 x 40 400X
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Images in a compound microscope appear upside
down and backwards.
Examples
e
e
Would become
t
t
Would become
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• B. How to properly use a microscope
• Adjust the microscope to the low power objective
  and raise the stage to top position.
• Center the specimen over the light that is coming
  up through the hole in the stage.
• Look through the eyepiece of the microscope and
  adjust light so that it is comfortable for your
  eyes.
• Use coarse focus knob until object comes into
  view and then use fine adjustment to get sharp
  focus.
• You may then use higher power objectives with
  fine adjustment knob only.

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Dissecting Microscopes (also known as
Stereoscopes) Dissecting microscopes are
used to view an image in 3D format. Images are
not inverted or upside down.
Dissecting microscopes can not magnify as well as
a compound light microscope.
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C. Measuring with microscopes

• The area of the slide that you see when you look
  through a microscope is called the Field of
  View.
• You need to know the size of your field of view
  to estimate the size of the object.
• Use a thin metric rule to determine the size of
  field of view in millimeters (mm).
• Convert millimeters to micrometers using
• 1 millimeters 1000 micrometers

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Quick trick just move decimal 3 places to the
right Practice the following 1.3 mm 2.4 mm
.8 mm .25
1300 micrometers
2400 micrometers
800 micrometers
250 micrometers
The symbol for a micrometer is ?m
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Determining field of view when you change power
We can use proportions to determine the field of
view when the magnification changes Low power
Low field of view High power
High power field of view

Example If the diameter of the field of view on
low power (40X) is 4000 micrometers, determine
the field of view for medium power (100X)
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Example If the diameter of the field of view on
low power (40X) is 4000 micrometers, determine
the field of view for medium power (100X)
40X
?

ANS 1600 ?m
100X
4000?m
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• Estimating the size of an object with field of
  view
• Calculate the diameter of the field of view for
  the power of magnification.
• Looking through the eyepiece, estimate how many
  times the object will fit across the field of
  view.
• Calculate the size of the object using the
  formula below.
• Size of object diameter of field of view (in
  ?m)
• Number of times object fits across
• Remember to use ?m

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EXAMPLE
The image of the amoeba to the left is seen under
medium power (100X) with field of view 1600 ?m
Calculate size of the amoeba
The amoeba would fit across the field of view 2
times. Therefore, the approximate length of the
amoeba is 800 ?m or 0.8 mm.