Science of Biology Notes

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Science of Biology Notes
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First of all, what is science?

• Draw a vertical line on your paper, and label the
  two sides as science and not science
• Brainstorm a few examples of specific academic
  disciplines on each side
• (besides the normal broad high school classes
  like English, Math, Science, Social Studies)
• Take a minute

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What is Science? (1-1)

• The root sci- means to know. Science is one
  way of investigating the world in which we live.
  Science strives to
• explore and understand the natural world,
• explain events in the natural world, and
• use those explanations to make useful
  predictions.
• Are some things unpredictable?

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Things that are not science include things like

• Art
• Religion
• Literature
• Opinion

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Is science better than these things?

• No! it is simply another way of exploring the
  world in which we live
• Science can only concern itself with testable
  things and\or observable things

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Is scientific knowledge a set truth?

• No!
• In our scientific explanations, we explain how
  things work using the knowledge we have to
  explain natural phenomena
• When our knowledge base changes, our explanation
  may change

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What is Science? (1-1)

• Scientists use observations (process of gathering
  information by using your five senses) to gather
  data.
• They also use known data to make inferences (a
  logical interpretation of the data based on past
  experiences).
• Practice

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Determine in the picture if it is an observation
(O) or an inference (I)
O

1. _____ There are 2 doors.
2. _____ The people are fighting because someone
   ate their cookies.
3. _____ One door is closed.
4. _____ They are hitting each other hard.
5. _____ Glass is broken.

I
O
I
O
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What do scientists do?

• BASIC SKILLS
• 1. Observing- Noting the properties of objects
  and situations using the five senses
• 2. Classifying- Relating objects and events
  according to their properties or attributes
  (Involves classifying places, objects, ideas, or
  events into categories based on their
  similarities.)
• 3. Space/Time Relations- Visualizing and
  manipulating objects and events, dealing with
  shapes, time, distance, and speed

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What do scientists do?

• BASIC SKILLS
• 4. Using numbers- Using quantitative
  relationships, e.g. scientific notation, error,
  significant numbers, precision, ratios, and
  proportions
• 5. Measuring- Expressing the amount of an object
  or substance in quantitative terms, such as
  meters, liters, grams, newtons, etc.
• 6. Inferring- Giving an explanation for a
  particular object or event
• 7. Predicting- Forecasting a future occurrence
  based on past observations or the extension of
  data

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What do scientists do?

• INTEGRATED SKILLS
• 8. Defining Operationally- Developing statements
  that present a concrete description of an object
  or event by telling one what to do or observe.
• 9. Formulating models- Constructing images,
  objects, or mathematical formulas to explain
  ideas
• 10.Controlling variables- Manipulating and
  controlling properties that relate to simulations
  or events for the purpose of determining
  causation in experimental research design

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What do scientists do?

• INTEGRATED SKILLS
• 11. Interpreting Data- Arriving at explanations,
  inferences, or hypotheses from data that have
  been graphed or placed in a table (this
  frequently involves concepts such as mean, mode,
  median, range, frequency, distribution,
  chi-square test, t test)
• 12.Hypothesizing- Stating a tentative
  generalization of observations or inferences that
  may be used to explain a relatively larger number
  of events but that is subject to immediate or
  eventual testing by one or more experiments in
  experimental research design
• 13.Experimenting- Testing a hypothesis through
  the manipulation and control of independent
  variables and noting the effects on a dependent
  variable interpreting and presenting results in
  the form of a report that others can follow to
  replicate the experiment using experimental
  research design

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How Scientists Work

• The Scientific MethodScientists solve
  problems, but the method may vary based on the
  problemThe three types of investigations
• Experimental Research Design
• Correlation
• Descriptive Investigation

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Steps to Experimental Scientific Investigation
(The Scientific Method)

• 1. Observe make an observation of the world
  around you. There are two kinds of observations
• Qualitative observation descriptive observation
• Ex The plant is green.
• Quantitative observation a numerical
  observation.
• Ex The flask contains 12.45 ml. There are 4
  pennies.
• Which kind of observation? Lets practice!

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Determine if the statement is qualitative (A) or
quantitative (B).
A

• _____ The sky is blue.
• _____ There are 4 clouds.
• _____ There are 3 hills.
• _____ The first hill is small.
• _____ The clouds are small.
• _____ There are a total of 38 birds.

B
B
A
A
B
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Franceso Redi

• 400 years ago, people believed that living things
  appear spontaneously from non-living matter
  (spontaneous Generation). Francesco Redi however
  wanted to disprove this idea. He considered it
  likely that flies laid eggs too small for people
  to see.

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• 2. Ask a question based on your observation,
  ask a question to investigate.
• Ex. Redi asked the question How do new living
  things, or organisms, come into being?
• 3. Research - Look in books, journals and the
  internet to make additional observations and
  research about the questions you made from your
  observation.

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• 4. Formulate a hypothesis - Propose a
  scientific explanation to the question being
  observed and researched. The statement must be
  testable. (Which is best? does not lend itself
  to being tested). At the end of the
  investigation, you will either accept or reject
  your hypothesis.
• Ex. If meat is left uncovered, then flies will
  leave eggs on the meat, creating maggots.

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• 5. Perform a controlled experiment - Develop and
  use the experimental design to test your
  hypothesis. Whenever possible, the hypothesis
  should be tested by an experiment in which only
  one variable is changed at a time. All other
  variables should be kept unchanged, or controlled.

Testing fertilizers on plant growth? Keep all
other factors constant!
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• Ex. Redi created a controlled experiment in which
  only 1 variable was deliberately changed each
  time. Redi was able to determine that when the
  gauze was not present, flies could reach the meat
  and maggots would appear. When gauze was present,
  flies could not reach the meat and no maggots
  would appear.

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• Variables Factor being tested
• Controlled- Variables that are kept constant
• Independent- Variable being manipulated (in a
  graph found on the x-axis or the horizontal axis)
• Dependent- Variable that responds (in a graph
  found on the y-axis or the vertical axis)
• Control Group the group where the independent
  variable is NOT applied. Meaning, nothing is
  changed. Used for comparison.

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A way to remember variables

• Dependent
• Responding
• Y - axis
• Manipulated
• Independent
• X - axis

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• Independent variable? ____________
• Dependent Variable? _____________
• Controlled Variables? _____________
• Control Group? ________________

Cover on the jar
Maggots
Type of meat, size of jar
No cover on the jar
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Repeat your experiment!

• The more times you do it, the more accurate your
  data and results will be!!

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• 6. Observe again - Collect data (measurements)
  and perform analysis on the data using graphs and
  charts

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• 7. Draw conclusions - State whether or not the
  evidence supports the hypothesis based on your
  data and analysis.
• Please notice that we do not prove hypotheses!
  Proof exists when the chance for error is 0.
  There is always some chance for error (no matter
  how small it is) and this existence of chance
  error means we cannot prove anything in true,
  honest, science.

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• 8. Report back to the community Experiments
  results can be used by other to help them with
  their own experiments. This is what keeps
  science progressing.

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What is the difference between a hypothesis, a
theory, and a law?

• A hypothesis is a possible explanation for a set
  of observations. It has not yet been thoroughly
  tested.

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What is the difference between a hypothesis, a
theory, and a law?

• A theory is a well tested explanation that
  unifies a broad range of observations.
• A theory explains observations simply and
  clearly, and predictions can be made from them.
• It is widely accepted by the scientific
  community.

Theory of Plate Tectonics
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What is the difference between a hypothesis, a
theory, and a law?

• A law is a summary of observed natural events
  they are less comprehensive than theories and
  normally are associated with a mathematical
  expression. It is also widely accepted by the
  scientific community.

Law of Universal Gravitation
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Studying Life

• What is Biology?
• Etymology bio means life, -ology means the
  study of-
• Characteristics of Living Things all living
  things have all eight things in common

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Studying Life

• 1) They are made up of units called cells.

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2) Reproduction (sexually or asexually)
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3) Has a universal genetic code (DNA or RNA)
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4) Grows and develops
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5) Responds to the environment
http//www.ciadvertising.org/studies/student/99_sp
ring/theory/eileen/mytheo/passion3.gif
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6) Obtains and uses materials and energy
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7) homeostasis- maintains a stable internal
environment
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8) Evolution- Groups change over time
http//www.ichthus.info/Evolution/PICS/horse-evol.
jpg
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Branches of Biology

• Biology is studied at many levels of organization
  from simple to complex
• 1) Molecules groups of atoms

Atoms ?
Molecules ?
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2) Cell smallest functional unit of life
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3) Groups of cells tissues, organs, and organ
systems
http//68.90.81.6/ScienceTAKS/Integration/Cells_fi
les/image022.jpg
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4) Organism individual living system
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5) Population group of organisms of one type
that live in the same area
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6) Community populations that live together in
a defined area
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7) Ecosystem community and its nonliving
surroundings
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8) Biosphere the part of Earth that contains
all ecosystems
http//oceancolor.gsfc.nasa.gov/SeaWiFS/ICONS/seaw
ifs_biosphere_icon.jpg
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Tools and Procedures (1-4)

• Biologists use metric measurement (the SI system)
  to gather and interpret data.
• SI is the universal measurement system.

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Tools and Procedures (1-4)
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Conversions

• The metric system is universal measurement system
  based on the number 10. The meter is the
  distance value, the gram is the mass value, and
  the liter is the volume value.

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Conversions

• If you want to change a larger unit into a
  smaller unit, move the decimal point to the
  right.
• If you want to change a smaller unit to a larger
  unit move the decimal point to the left.
• Example problems
• Convert 100 g to kg. 100.0 g
• 0.0074 kL ________________ L

.1 kg
7.4
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Scientific Notation

• to make large or small numbers easier to read
• Numbers that are very small (many numbers after
  the decimal) have negative exponents
• Numbers that are very large (many numbers before
  the decimal) have positive exponents

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Scientific Notation

• The goal is to have a single non-zero number to
  the left of the decimal (1-9) and the exponent at
  the end tells you how many decimal places over in
  which direction you would move to get to the
  original number.
• Scientific Notation is really only useful if it
  will make the number shorter. If the number does
  not have several zeros in front or behind of the
  number taking up space, scientific notation will
  only make the number longer. Keep this in mind
  when converting.

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Scientific Notation

• Example
• 0.0000000001 kg is easier to read as 1.0 x 10-10
  kg
• 1094600000 cm is easier to read as 1.0946 x 109
  cm
• Practice problems
• 1980084600000 g _____________________
• 0.00034568 cm _______________________
• 14698 g _____________________________

1.9800846 x 1012
3.4568 x 10-4
14698
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Graphing- how a scientists shows patterns in data
collected.

• There are several kinds of graphs not all of
  them are useful for data communication. Which
  type of graph is appropriate for which situations?

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Line Graph

• Line graph - compares two things in which items
  on one axis affect the items on the other axis.
  If you are comparing anything to time, it is
  usually a line graph.
• (Ex. Amount of CO2 in the atmosphere over the
  last 6 decades)

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Line Graph
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• Bar graph - compares two or more values. (Ex.
  Number of students with red hair in each class)

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Bar Graph
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• Pie Chart- effective in showing proportions or
  percentages of a whole thing. (Ex. Comparing
  the percentage vote that each candidate received
  in the election)

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Pie Chart
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Graphing

• Always draw lines with a ruler, use pencil, and
  use map pencils when necessary. Make sure your
  graph contains all components
• Title tell what you are comparing or displaying
  (be descriptive).
• X-axis label and give scale.
• Y-axis label and give scale.
• Key give meanings of the symbols and colors
  used on the graph.
• Data points clearly marked, and label them if
  you do not have grid lines.

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Microscopes

• Biologists use microscopes to see living things
  that are too small for the unaided eye. The two
  basic categories of microscopes are

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1) Light microscope produces magnified images
by focusing visible light rays. This microscope
can be used to magnify up to 1000 times
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2) Electron microscope produce magnified images
by focusing beams of electrons. This kind is
used to magnify tens and hundreds of thousands of
times for extremely small object like a virus.
The hair on the leg of a fly(magnified by a
factor of 1000)
Salt crystals on the antennas of an
insect(magnified by a factor of 5000)
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Other techniques and tools

1. Cell cultures - in order to study cells under a
   controlled condition, a biologist can take a
   single cell and place it in a Petri dish with
   nutrient solution to help the cell regenerate and
   fill the whole dish. This cell culture can be

• used to isolate a single kind of cell, or study
  interactions between cells and chemicals.

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Other techniques and tools

• 2. Cell fractionation - in order to study a
  single part of a cell, the cells can be lysed
  (burst open) and the broken cells can be added to
  a liquid and placed in a tube. This tube can be
  placed in a centrifuge which spins the tubes at
  high speeds which

• causes cell parts to settle at different levels
  based on their density, the densest parts will
  land on the bottom.

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Other techniques and tools

• 3. Autoclave - in order to sterilize tools and
  kill anything a scientist may have been growing
  to test, the must kill it with an autoclave. The
  large steel machine uses heat and pressure to
  raise the temperature

• above normal boiling point of water to a
  temperature in which no bacteria, viruses, or
  spores can survive.