The Science of Biology
What is Science? What is its
purpose?
• To investigate questions
• To support or refute a theory
• To gain knowledge
The Scientific Method!
 State the Question
 Form a Hypothesis
 Conduct an Experiment
 Collect Data
 Draw A Conclusion
Qualitative vs. Quantitative
Qualitative
Quantitative
 Describes data using
 Describes data with
words
 Quality
numbers
 Quantity
 Ex. There are many
 Ex. There are 14 cars
red cars in the
parking lot
in the parking lot
Designing an Experiment
How many variables are in a
typical experiment?
How many variables can be
tested at one time?
The main parts of an experiment
 Independent Variable (manipulated)
 Dependent Variable
(responding/result)
 Control
Determine the variables in the
experiment
 A botanist is studying the affect of fertilizer
on pea plants.
 She test 5 plants. She adds 6 oz of fertilizer
to plant 1, 7 oz of fertilizer to plant 2, 8 oz
to plant 3, 9 oz to plant 4 and no fertilizer
to plant 5. She waters each of the plants
with 200mL of water everyday for 2 weeks
and places them in the sun for 3 hours each
day.
Homework  ( Due Tuesday 8/11)
 Experimental Design Assignment
 Design an experiment to answer a question you have about
the natural world
 Design needs to include:
 The question being investigated
 Your hypothesis (“if then statement”)
 Procedures (how would you test it)
 Variables
 Data Collection ( how would you collect data)
Key Experiments From the Past
 Francesco Redi: Refuted Spontaneous
Generation
 John Needham: Retested Redi’s
experiment
 Lazzaro Spallanzani: Retest Redi’s
Experiment
Key Experiments From the Past
 Louis Pasteur: Spontaneous Generation
 Pasteurization & sterilization
Characteristics of Living Things
1. Made of Cells
2. Reproduce
3. Based on Universal Genetic Code
4. Grow and Develop
5. Obtain and Use Materials and Energy
6. Respond the Their Environment
7. Maintain a Stable Internal Environment
(homeostasis)
8. Change Over Time
The Metric System Units:
 Length = The __________ from one point
to another
 Volume = The amount of ________ an
object takes up
 Mass = The amount of __________ in an
object
 Temperature = The measure of
_________ or _________
SI Units
 Length = m
 Volume (solid) = cm3
 Volume (liquid) = mL
 Mass = kg
 Temperature = Celsius
Scientists often record their data in a
table or _______.
There are multiple types of graphs:
______, _______, or a ____ ______.
 X- axis is along the
___________plane
 Y-axis is along the __________plane
Microscopes
 Light Microscope: produces magnified
images by focusing _______ _______ ____.
 Most commonly used microscope
 Compound Light Microscope: allows light to
pass through the specimen and uses _____
lenses to form an image.
Lab report format
Length
Width
Height
Volume
Trial 1
Trial 2
Trial 3
Average
Circumference
Difference from
Average
Trial 1
Trial 2
Trial 3
Average
X
Sodium Table
Mass of
Mass of
Sodium and Beaker (g)
Beaker (g)
Trial 1
Trial 2
Trial 3
Average
Mass of
Sodium
Chloride (g)
Pre Lab Quiz
1.
What is the metric unit used to measure mass?
2. What is the metric unit used to measure length?
3. What information will you be collecting about the
block?
4. What information will you be collecting about the
sodium chloride?
5. What is one lab safety rule you think you should follow
during lab?
Post Lab Questions
1.
Did you and your partner measure the same distance
for each side of the block? If not, what do you think
may have caused the discrepancy?
2. What parts of the lab activity provided opportunities
for human error?
3. Why is it important to ALWAYS include the metric
units of the measure in your data?
Microscopes
Electron Microscope: produces
magnified images by focusing ______
of ________.
 Can produce images almost
1000 times more detailed
than a light microscope.
Two Types of Electron Microscopes:
 Transmission Electron Microscope (TEM):
shine a beam of electrons through a thin
specimen.
 Scanning Electron Microscope (SEM): scan
a narrow beam of electrons back and forth
across the ____________ of the specimen.