Biology: The Study of Life
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
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
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
So, What Is The difference:
Growth Vs.
Development
Adapt Vs.
Evolve
Growth: Refers to
an increase in size.
Adapt: Inheritance
of traits that make
you better suited
for the Env.
Development:
Deals with
maturation
Evolution: The
sum of all the
Successful
adaptations.
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.
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.
Types of Observations:
Qualitative
NOT measured
using numbers.
IE: Beauty
Observation
and/or Data
Can be measured
Quantitative
IE: Height,
weight, etc
What kinds of observations is
he making?
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
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.
Applying The Scientific Method
make observations /
state problem
form hypothesis
design controlled
experiment
collect data
may support
hypothesis
draw conclusion /
publish
analyze results
may not support
hypothesis
form a new
hypothesis
The Scientific Method
Students (state the problem)
Hate
Every
Dumb
Class
(hypothesis)
(experiment)
(data)
(conclusion)
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
Name those variables!
In other words…
Independent
Variables
Dependent
Variables
Descriptions
Descriptions
Cause
Before
Input
What you do
IF
\Effect
After
Output
What happens
THEN
Dependent Vs. Independent
Variables
Types of
Variables
Dependent
variables
(responding )
Independent
Variable
(manipulated)
Is Always
graphed on Yaxis (DRY)
Is Graphed on
the X- Axis
MIX
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.
An Example Experiment
Mrs. Fernandez’s 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.
0 mL
3 mL
6 mL
Your Turn….
 What is the independent variable in
Dominick’s 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?
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?
 What’s the main idea?
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
III. Other things to keep in mind:
A. Always use metric system!
 Distance: meters
 Volume: liters
 Temperature: oC
 Mass: grams
Ladder Method
1
2
KILO
1000
Units
3
HECTO
100
Units
DEKA
10
Units
DECI
0.1
Unit
Meters
Liters
Grams
How do you use the “ladder” method?
1st – Determine your starting point.
2nd – Count the “jumps” to your ending point.
3rd – Move the decimal the same number of
jumps in the same direction.
CENTI
0.01
Unit
MILLI
0.001
Unit
4 km = _________ m
Starting Point
Ending Point
How many jumps does it take?
4. __. __. __. = 4000 m
1
2
3
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.
Redi’s Experiment on
Spontaneous Generation
OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.
HYPOTHESIS: Flies produce maggots.
PROCEDURE
Uncovered jars
Covered jars
Controlled Variables:
jars, type of meat,
location, temperature,
time
Several
days pass
Manipulated Variables:
gauze covering that
keeps flies away from
meat
Responding Variable:
whether maggots
appear
Maggots appear
No maggots appear
CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not
occur.
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?
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?
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?
Your Turn..
Do the next three examples on your own
and see how well you understand the
concept.
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?
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?
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?
What is the Diff?
 A scientific Law explains a natural
phenomena and is consistently observed
The law of gravity & Newton's Law’s of Motion
 A Theory is a well tested and complex
explanation based on much
experimentation and collection of factsThe theory of evolution & theory of relativity
But That’s 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!
Oh no… Here come the metric
problems!
Practice, practice, practice until your good
becomes your better and your better
becomes your best!
Metric Units
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)
Click the image to
watch a short video
about the meter.
1 Meter = 1000 Millimeters (mm)
Which is larger?
A. 1 meter or 105 centimeters
C. 12 centimeters or 102 millimeters
B. 4 kilometers or 4400 meters
D. 1200 millimeters or 1 meter
Measuring Length
How many millimeters are in 1 centimeter?
1 centimeter = 10 millimeters
What is the length of the line in centimeters? _______cm
What is the length of the line in millimeters? _______mm
What is the length of the line to the nearest centimeter? ________cm
HINT: Round to the nearest centimeter – no decimals.
Ruler: http://www.k12math.com/math-concepts/measurement/ruler-cm.jpg
Metric Units
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)
Kilogram Prototype
Click the image to
watch a short video
about mass.
1 Gram (g) = 1000 Milligrams (mg)
Which is larger?
A. 1 kilogram or 1500 grams
C. 12 milligrams or 12 kilograms
B. 1200 milligrams or 1 gram
D. 4 kilograms or 4500 grams
Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram
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_Triple_Beam_750-SO.jpg
Bottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg
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
Metric Units
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?
A. 1 liter or 1500 milliliters
Click the image to
watch a short video
about volume.
B. 200 milliliters or 1.2 liters
C. 12 cm3 or 1.2 milliliters*
* When referring to water
Liter Image: http://www.dmturner.org/Teacher/Pictures/liter.gif
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
What causes the meniscus?
A concave meniscus occurs when the molecules of the liquid
attract those of the container. The glass attracts the water on
the sides.
Top Image: http://www.tea.state.tx.us/student.assessment/resources/online/2006/grade8/science/images/20graphicaa.gif
Bottom Image: http://morrisonlabs.com/meniscus.htm
What is the volume of water in each cylinder?
Pay attention to the scales for each cylinder.
Images created at http://www.standards.dfes.gov.uk/primaryframework/downloads/SWF/measuring_cylinder.swf
Measuring Liquid Volume
Measuring Solid Volume
9 cm
We can measure the volume of regular object
using the formula length x width x height.
8 cm
_____ X _____ X _____ = _____
We can measure the volume of
irregular object using water displacement.
Amount of H2O with object = ______
About of H2O without object = ______
Difference = Volume = ______
http://resources.edb.gov.hk/~s1sci/R_S1Science/sp/e
n/syllabus/unit14/new/testingmain1.htm
10 cm
1
Remember the Ladder Method
2
KILO
1000
Units
3
HECTO
100
Units
DEKA
10
Units
DECI
0.1
Unit
Meters
Liters
Grams
How do you use the “ladder” method?
1st – Determine your starting point.
2nd – Count the “jumps” to your ending point.
3rd – Move the decimal the same number of
jumps in the same direction.
CENTI
0.01
Unit
MILLI
0.001
Unit
4 km = _________ m
Starting Point
Ending Point
How many jumps does it take?
4. __. __. __. = 4000 m
1
2
3
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
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. <
26. >
27. =
28. =
29. <
30. >
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).
Differentiate between Compound
Light Microscopes and Electron
Microscopes
Compound Light
How is object
viewed?
What is the
magnification?
________
light passes
through object
_______ x ______
eyepiece
objective
up to ______x
2000
Electron
beam of _______
electrons
illuminates object
much greater
magnification
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
Label the parts of the
microscope:
a
d
e
f
g
h
b
c
a- eyepiece
b- stage
c- diaphragm
d- coarse adjustment
e- fine adjustment
f- arm
g- objective
h- base
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
More on Microscopes
 In the microscope’s the field of view is
always a circle
 ALWAYS label total magnification on
your drawings
Then label name
of specimen and
identified structures
More on Microscopes
Measuring the microscope field of view on lowest power1. Place a clear plastic ruler with mm markings on top of the
stage of your microscope.
2. Using lowest power objective, focus your image.
3. Count how many divisions of the ruler fit across the diameter
of the field of view.
4. Multiply the number of divisions by 1000 to obtain the field of
view in micrometers (µm). Record this in µm (micrometers)
(1mm = 1000 µm)
Microscopes
 What is a light/compound microscope?
Click on the link below for more microscope facts
 compound microscope facts
Microscopes
What is an electron microscope?
Allows scientists to view a universe too small to
be seen with a light microscope. They don’t use
light waves; they use electrons (negatively charged
electrical particles) to magnify objects up to two
million times.
What is the difference between TEM
(transmission electron microscope) and a SEM
(scanning electron microscope)?
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 white…why?
Electron Microscope game
 Click the link!
microscope game