Biology: The Study of Life

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Biology The Study of Life
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I. Science means to know (in Latin)

• A. Science is
• A body of knowledge
• A process to learn about
• the world
• B. Biology is
• Study of Life
• Biologists study the diversity of Life

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• Characteristics of Living Things
• 1-Living things are made up of cells
• 2-Living things reproduce (not essential for
  survival but essential for continuation of
  species)
• species group of organisms that can
  interbreed and produce fertile offspring
• 3-Living things change?growth and development

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• 4-Living things adjust to their surroundings
  (stimulus / response interactions)
• 5-Maintain homeostasis (balance internal
  condition)
• 6-Living things adapt and evolve
• 7-All Living things must get and use energy
• 8-Have a DNA genome
• Living Organisms possess ALL of the
  characteristics of life

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So, What Is The difference
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Homeo. What???

• Homeostasis Process by which organisms maintain
  constant and stable internal conditions.
  (temperature, blood glucose levels, hormone
  levels)
• Your body works like the furnace and
  thermostat in your home. The negative feedback
  loops run until they get to the proper level,
  like the temperature setting of the thermostat
  and then stops until they need to be adjusted
  again.

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The Scientific Method a method of investigation
involving observation and theory to test
scientific hypotheses

• Observation Using your senses to gather data.
• Inference The process of drawing logical
  explanations about what something means.
• Hypothesis A testable statement and possible
  explanation of an event based on prior knowledge
  and observations
• Prediction A prediction is a statement or claim
  that a particular event will occur in the future.
  Usually written as an If /Then statement.

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Types of Observations
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What kinds of observations is he making?
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• Kinds of DATA
• Quantitative produces numerical data that can
  be comparatively analyzed in graphs and tables
• a. Tables Title Table, Columns Rows have
  titles
• b. Graphs -3 main types
• line Graphs (measures change/
  time)
• bar (used for comparing groups)
• circle (pie) (shows )
• Qualitative Descriptive data written
  descriptions of observations

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Observation Vs.Inference Activity

• Mrs. Wade will be absent for the rest of the
  term. She won the lottery and thus decided to
  take a cruise around the world with her friends,
  Mrs. Walton and Mrs. Fernandez. She has left each
  team a bag personal items. She would like you to
  make 2 observations and two inferences about the
  contents (you have 5 minutes for this activity).
• Non-related example You observed that the ground
  was wet. Therefore, you infer that it had just
  rained.

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Applying The Scientific Method
make observations / state problem
form hypothesis
design controlled experiment
collect data
analyze results
may not support hypothesis
may support hypothesis
draw conclusion / publish
form a new hypothesis
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The Scientific Method

• Students (state the problem)
• Hate (hypothesis)
• Every (experiment)
• Dumb (data)
• Class (conclusion)

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B. Parts of a Controlled Experiment

• Types of Variables
• Independent variable (on x-axis)
• (aka Manipulated variable)
• a factor that is manipulated/determined by
  experimenter to see what the result will be
• Dependent variable (on y-axis)
• (aka Responding variable)
• a factor that responds to the changes in the
  independent variable what the experimenter is
  looking for

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Name those variables!
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In other words
Independent Variables Descriptions Dependent Variables Descriptions
Cause \Effect
Before After
Input Output
What you do IF What happens THEN

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Dependent Vs. Independent Variables
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Parts of a Controlled Experiment

• Control Group the group for which the testing
  conditions are not applied (may receive the
  Placebo).
• Experimental groups
• the groups where all conditions are held constant
  EXCEPT the one being tested
• Controlled variables (controls) Variables that
  the experimenters keep the same throughout the
  experiment.

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An Example Experiment

• Mrs. Fernandezs son, Dominick, would like to
  know what will happen to his gummy bears if he
  places them in water. So, he obtains three (3)
  gummy bears (all are of the same brand). He
  places one in 20 mls of water for 3hrs, the other
  for 12 hrs, and the last for 24 hrs. He uses a
  25ml graduated cylinder each bear.

3 mL
6 mL
0 mL
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Your Turn.

• What is the independent variable in Dominicks
  experiment? In what axis do graph it?
• What is the dependent variable in the experiment?
  In what axis do you graph it?
• What are the controlled variables in the
  experiment?

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C. Drawing a Conclusion

• The conclusion should always have two main parts.
• Confirm or reject the hypothesis
• Was the hypothesis correct?
• Overall statement of what was learned
• What happened and why did it happen?
• Whats the main idea?

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D. Publishing Results

• When a hypothesis has been tested and supported
  many times, a theory may be developed and
  published.
• A Theory is the best explanation science has to
  offer about a problem after much experimentation
  and collection of facts.
• A scientific Law explains a natural phenomena and
  is consistently observed

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III. Other things to keep in mind

• A. Always use metric system!
• Distance meters
• Volume liters
• Temperature oC
• Mass grams

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Ladder Method
KILO1000Units
HECTO100Units
DEKA10Units
DECI0.1Unit
CENTI0.01Unit
MILLI0.001Unit
4 km _________ m
How many jumps does it take?
4.
4000 m
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Gummy Bear Lab

• Read lab directions in lab hand-out and on board
• Conduct the lab.
• Clean up (everything must be spotless when lab is
  completed).
• Graph and answer questions
• Turn in assignment.

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Let's Review
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Redis Experiment onSpontaneous Generation
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Identifying Variables

• Two groups of students were tested to compare
  their speed working math problems. Each student
  was given the same problems. One group used
  calculators and the other group computed without
  calculators.
• What is the independent/manipulated variable?
• What is the dependent/responding variable?
• What is the controlled variable?

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Identifying Variables

• A study was done with an electromagnet system
  made from a battery and wire wrapped around a
  nail. Different sizes of nails were used and the
  number of paper clips that the electromagnet
  could pick up was measured.
• What is the manipulated variable?
• What is the responding variable?
• What are the controlled variables?

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Identifying Variables

• A study was attempted to find if the length of
  the string in a string telephone affected its
  sound clarity.
• What is the independent variable?
• What is the dependent variable?
• What are the controlled variables?

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Your Turn..

• Do the next three examples on your own and see
  how well you understand the concept.

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Identifying Variables

• An experiment was performed to determine how the
  amount of coffee grounds could affect the taste
  of coffee. The same kind of coffee, the same
  percolator, the same amount and type of water,
  the same perking time, and the same electrical
  source were used.
• What is the manipulated variable?
• What is the responding variable?
• What are the controlled variables?

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Identifying Variables

• Students of different ages were given the same
  puzzle to assemble. The puzzle assembly time was
  measured.
• What is the independent/manipulated variable?
• What is the dependent/responding variable?
• What is the controlled variable?

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Identifying Variables

• A study was done to find if different tire treads
  affect the braking distance of a car.
• What is the independent variable?
• What is the dependent variable?
• What is the controlled variable?

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What is the Diff?

• A scientific Law explains a natural phenomena and
  is consistently observed
• The law of gravity Newton's Laws of Motion
• A Theory is a well tested and complex explanation
  based on much experimentation and collection of
  facts-
• The theory of evolution theory of relativity

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But Thats NOT All ALL!

• How is THEORY used in everyday speech that is
  scientifically incorrect?

• Michael might say that he has a theory that Mrs.
  Wade will yell at the class today

• What would be a more ACCURATE word to use?

• If he had made the same statement but had
  replaced theory with hypothesis, THEN he would be
  scientifically correct!

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Oh no Here come the metric problems!

• Practice, practice, practice until your good
  becomes your better and your better becomes your
  best!

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km
Metric Units
m
cm
mm
The basic unit of length in the metric system in
the meter and is represented by a lowercase
m. Standard The distance traveled by light in
absolute vacuum in 1/299,792,458 of a second.
Metric Units 1 Kilometer (km) 1000 meters 1
Meter 100 Centimeters (cm) 1 Meter 1000
Millimeters (mm)
Click the image to watch a short video about the
meter.
Which is larger?
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Measuring Length
How many millimeters are in 1 centimeter?
Ruler http//www.k12math.com/math-concepts/measur
ement/ruler-cm.jpg
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kg
Metric Units
cg
mg
g
Mass refers to the amount of matter in an
object. The base unit of mass in the metric
system in the kilogram and is represented by
kg. Standard 1 kilogram is equal to the mass of
the International Prototype Kilogram (IPK), a
platinum-iridium cylinder kept by the BIPM at
Sèvres, France.
Metric Units 1 Kilogram (km) 1000 Grams (g) 1
Gram (g) 1000 Milligrams (mg)
Click the image to watch a short video about mass.
Which is larger?
Kilogram Prototype Image - http//en.wikipedia.org
/wiki/Kilogram
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Measuring Mass
We will be using electronic balances to find the
mass of various objects in this course. A weigh
boat, paper towel of some container with be
placed on the balance first and you will tare it,
zero it out. The the objects are placed in the
container and on the scale. The digital read-out
has two decimal places, which is the mass of the
object in grams.
Top Image http//www.southwestscales.com/Ohaus_Tr
iple_Beam_750-SO.jpgBottom Image
http//www.regentsprep.org/Regents/biology/units/l
aboratory/graphics/triplebeambalance.jpg
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Measuring Mass Electronic Balance
a- make sure the balance reads 0.00 g b-place
weigh boat or container you will use to hold the
material that is to be massed on balance and
press ON button just long enough for the read-out
to once again show 0.00 g (tare weigh boat) c.
remove the weigh boat and put the material in
it d. carefully place full weigh boat on balance
and read to 2 decimal places e- remove items,
clean up, zero out balance
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kL
Metric Units
cL
mL
L
Volume is the amount of space an object takes up.
The base unit of volume in the metric system in
the liter and is represented by L or l. Standard
1 liter is equal to one cubic decimeter
Metric Units 1 liter (L) 1000 milliliters
(mL) 1 milliliter (mL) 1 cm3 (or cc) 1 gram
Which is larger?
Click the image to watch a short video about
volume.
A. 1 liter or 1500 milliliters B. 200 milliliters
or 1.2 liters C. 12 cm3 or 1.2 milliliters
When referring to waterLiter Image
http//www.dmturner.org/Teacher/Pictures/liter.gif
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Measuring Volume
We will be using graduated cylinders to find the
volume of liquids and other objects.
Read the measurement based on the bottom of the
meniscus or curve. When using a real cylinder,
make sure you are eye-level with the level of the
water. What is the volume of water in the
cylinder? _____mL
Top Image http//www.tea.state.tx.us/student.asse
ssment/resources/online/2006/grade8/science/images
/20graphicaa.gifBottom Image http//morrisonlabs
.com/meniscus.htm
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Measuring Liquid Volume
What is the volume of water in each cylinder?
Images created at http//www.standards.dfes.gov.uk
/primaryframework/downloads/SWF/measuring_cylinder
.swf
A
B
C
Pay attention to the scales for each cylinder.
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Measuring Solid Volume
We can measure the volume of regular object using
the formula length x width x height.
_____ X _____ X _____ _____
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Remember the Ladder Method
KILO1000Units
HECTO100Units
DEKA10Units
DECI0.1Unit
CENTI0.01Unit
MILLI0.001Unit
4 km _________ m
How many jumps does it take?
4.
4000 m
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Lets Practice Metric Conversions!!!
Write the correct abbreviation for each metric
unit. 1) Kilogram _____ 4) Milliliter _____
7) Kilometer _____ 2) Meter _____ 5)
Millimeter _____ 8) Centimeter _____ 3) Gram
_____ 6) Liter _____ 9) Milligram _____ Try
these conversions, using the ladder method. 10)
2000 mg _______ g 15) 5 L _______ mL 20) 16
cm _______ mm 11) 104 km _______ m 16) 198
g _______ kg 21) 2500 m _______ km 12) 480
cm _____ m 17) 75 mL _____ L 22) 65 g
_____ mg 13) 5.6 kg _____ g 18) 50 cm _____
m 23) 6.3 cm _____ mm 14) 8 mm _____ cm
19) 5.6 m _____ cm 24) 120 mg _____ g
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Conversion Challenge 1. kg 2. m 3. g 4. ml 5.
mm 6. L 7. km 8. cm 9. mg 10. 2 g 11. 104000
m 12. 4.8 m 13. 5600 g 14. .8 cm 15. 5000
ml 16. 0.198 kg 17. 0.075 l 18. 0.5
m 19. 560 cm 20. 160 mm 21. 2.5 km 22. 65000
mg 23. 63 mm 24. 0.12 g 25. lt 26. gt 27. 28.
29. lt 30. gt
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Microscopes
Around 1590, two Dutch eye glass makers,
Zaccharias Janssen and his father Hans put
several lenses in a tube and invented the
compound microscope (which is a microscope that
uses two or more lenses). 
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Differentiate between Compound Light Microscopes
and Electron Microscopes
Compound Light Electron
How is object viewed? ________ passes through object beam of _______ illuminates object
What is the magnification? _______ x ______ up to ______x
light
electrons
eyepiece objective
much greater magnification
2000
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More on Microscopes
The eyepiece or ocular lens usually has a
magnification of 10 times (10x) Total
magnification is determined by multiplying the
eyepiece magnification times the objective lens
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Label the parts of the microscope
a

• a- eyepiece
• b- stage
• c- diaphragm
• d- coarse adjustment
• e- fine adjustment
• f- arm
• g- objective
• h- base

d
e
f
b
g
c
h
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More on Microscopes

• The two lenses in compound microscopes are
  eyepiece (ocular) and objective (although there
  may be more than one)
• You always carry a microscope with two hands-
  grasping the arm and the base
• The specimen is placed on a slide and onto the
  stage when viewed

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More on Microscopes

• In the microscopes the field of view is always a
  circle
• ALWAYS label total magnification on your drawings
• Then label name
• of specimen and
• identified structures

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More on Microscopes

• Measuring the microscope field of view on lowest
  power-
• Place a clear plastic ruler with mm markings on
  top of the stage of your microscope. 
• Using lowest power objective, focus your image. 
• Count how many divisions of the ruler fit across
  the diameter of the field of view. 
• Multiply the number of divisions by 1000 to
  obtain the field of view in micrometers (µm).
  Record this in µm (micrometers) (1mm
  1000 µm)

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Microscopes

• What is a light/compound microscope?
• Click on the link below for more microscope
  facts
• compound microscope facts

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Microscopes

• What is an electron microscope?
• What is the difference between TEM (transmission
  electron microscope) and a SEM (scanning electron
  microscope)?

Allows scientists to view a universe too small to
be seen with a light microscope. They dont use
light waves they use electrons (negatively
charged electrical particles) to magnify objects
up to two million times.

• TEMs allows beams of electrons to go through the
• specimen while SEMs beams of electrons bounce
• off of the specimen and result in a 3D image.
• All images are black and whitewhy?

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Electron Microscope game

• Click the link!

microscope game