• AIM: How do we investigate the living
world?
• DO NOW: Read the first page of your
packet. Underline all of the main ideas.
Thursday 9/10/15
• AIM: How can we set up controlled
experiments?
• DO NOW: Over the summer I observed
that my sunflowers that were in my yard
were smaller than the sunflowers in the
alley. How can I determine why this
happened?
• HOMEWORK: Text read 11-13
Scientific Method
1. Make an observation
Based on your 5 senses
2. Research
find out what is already known about your
subject, & make your own observations
3. Form a Hypothesis
an educated guess or possible answer to
your observation that is based on your
research
4. Experiment
set up a situation to test your hypothesis
5. Record, Organize and analyzeData
•
•
keep track of your measurements and
observations
use graphs and
data tables to identify
trends in the data
6. Conclusion
•
•
•
•
does data support hypothesis??
explain what the data means
State if your hypothesis is true or false
Conclusions must be based on hard
evidence from your data
Tuesday 9/21/10
• AIM: How can we identify independent and
dependant variables in an experiment?
• DO NOW: Scientific Method handout, Back Page,
Francisco Redi
• Homework: Textbook Read pages 10-12. Answer
questions 1,2 and 5 on page 13
Designing an experiment
• Must have a purpose for investigation
• Experiment must be based on research, a
previous experiment or an observation
• Your EXPERIMENT should be based on
your hypothesis
Controlled Experiment
• Always setup in 2 sets
– Control Group
– Experimental Group
• an experiment in which only one variable is
manipulated at a time in order to establish a
cause/effect relationship.
• Why is it important to only manipulate one
variable at a time?
• You don't want more than one variable, or thing
that you're testing, because then, you don't know
which variable produced the result you obtained.
Which experimental setup is correct
and WHY?
Hypothesis, Theory & Law
Hypothesis: Prediction
•
•
needs to be tested,
may or may not be correct
Theory: Explanation
•
•
a former hypothesis that has been supported by
many experiments
can still be changed or discarded
Law
•
a theory that scientists are extremely confident
in (ex: the law of gravity)
Tuesday 9/22/09
• AIM: How can we set up a controlled experiment?
• DO NOW: 1- Copy your hw. 2- Use your plant research
projects to explain what seed germination is.
• Homework: In your project section, on a clean sheet of
paper, write your heading and develop a hypothesis and
controlled experiment related to your plant research.
Identify your independent and dependant variables,
control and experimental groups
• YOU WILL BE TESTING THIS HYPOTHESIS IN
CLASS!
Heading
• Hypothesis:
• Experiment
– Independent Variable
– Dependant Variable
– Control Group
Experimental Group
Seed germination
Controlled Experiments
• Set up two or more groups for comparison
• Groups are set up to be alike in all ways except one
• The one difference between the two groups at the start
of the experiment is called the “independent variable”
• The INdependent variable is the one you are IN
control of! Cause of change
• Dependant variable: Effected by the independent
variable
• Experimental Group(s) is (are) exposed to the
independent variable, the Control Group is not
Designing a controlled experiment
• Control setup use all the same equipment, same
conditions, but no variables are tested.
– Provides a baseline for which to compare the results with the
experimental setup.
• Experimental setup is set up exactly the
same way as the CONTROL, but one thing that
you want to measure is factored in.
– Uses the independent variable (cause) which
determines the dependent variable (effect).
Procedure
• Experimental procedures must be very
detailed and precise
• Must include specifics about amounts,
materials, temperatures and data collection
• Must be written step by step
Characteristics of Good
Experiments
Use large numbers in each group, this
increases the reliability of your results
Validity-other scientists should be able to
get similar results if they repeat your
procedures
Cautious Conclusions
• * don’t overstate the meaning of your data
• results could be affected by factors that
you are unaware of
Wednesday 9/22/10
• AIM: How can we organize our data?
• DO NOW: Explain how your height has
changed since the first grade.
• Homework: Textbook Read page 13.
Answer questions 3 and 4 page 13
How has your shoe size changed
since the first grade? Give an
estimate for each year.
Mrs Naus’shoe height over the years
How can we organize this data in a
more organized manor?
What are the different types of
graphs we can make?
Bar graphs, line graphs, pie charts
Using the data you collected,
organize your shoe size into a table
How can we use our table to
build a graph?
Setting up a line graph
•
Step 1:Identify Variables:
–
–
•
Independent: Goes on the X-axis
Dependent: Goes on the Y-axis
Step 2: Determine the variable range
–
•
Subtract the lowest data variable from the highest data variable
Step 3:Determine a scale(the numerical value for each
square) that best fits the range of each variable.
–
Spread the graph to use MOST of the available space.
Setting up a line graph
• Step 4: Number and label each axis.
– This tells what data the lines on your graph represent.
• Step 5: Plot the data points.
– Create a key or legend for multiple parts of data
• Step 6: Draw the graph
• Step 7: Title the graph
– your title should clearly tell what the graph is about
Thursday 9/23/10
• Homework: Text read pages 15 and 16
answer the reading check questions found
within the reading
DO NOW: Thursday 10/1/09
• Use the data table to
create a line graph
TIME (sec) Heart Rate
(bpm)
5
18
10
22
15
27
20
35
25
45
30
52
35
45
40
37
45
26
50
15
• Using the following
Time
data table create a graph(days)
Growth
Growth
Control(cm) Exp. (cm)
1
0
2
2
1
3
3
3
4
4
6
5
Monday 10/5/09
• AIM: Why is it important to be safe in the
lab?
• DO NOW: Read the paragraph and
underline the procedures you think are
incorrect
• HOMEWORK: Lab Safety Study Sheet
• EXAM FRIDAY!
•
Tuesday 10/6/09
• AIM: What are some of the lab instruments
that help us perform scientific experiments?
• DO NOW: handout Lab study sheet
• Homework: Lab Instrument handout
EXAM Friday
• Scientific Method
• Controlled Experiments: ind vs dep variable
– Control vs experimental grps
– Setting up line graphs
• Lab safety
• Lab instruments
Lab Equipment
Goggles
 USED
TO
PROTECT
YOUR EYES
DURING
EXPERIMEN
TS
Gloves
USED TO
PROTECT
YOUR
HANDS
DURING
EXPERIMENTS
Meter stick


Used to measure
distance
has millimeters,
centimeters &
inches on reverse
Thermometer
MEASURE
TEMPERATURE
IN DEGREES
CELSIUS (OC)
Triple Beam Balance
MEASURE
THE MASS
IN GRAMS
(g)
Beaker
Beakers hold solids or
liquids
Transfer of substances
Measure volume
Erlenmeyer flask
• Erlenmeyer flasks
hold solids or liquids
• Measure volume
Graduated Cylinder
A graduated
cylinder is used to
measure volumes of
liquids.
Milli Liter or Liter
Test tubes
• used to hold small
amounts of liquid
Thursday
Rubber Stoppers
Rubber stoppers are used
to close containers to avoid
spillage or contamination.
Containers should never be
heated when there is a
stopper in place.
Test tube holder
• is useful for holding a
test tube which is too
hot to handle.
Thursday
• AIM: How do lab instruments help us
perform controlled experiments?
• DO NOW: Get your plants. Today will be
your last measurement.
• Homework: your Final research project is
due on Tuesday
Test Tube Racks
Test tube racks are for holding and organizing test
tubes on the laboratory counter. Plastic racks may
melt in contact with very hot test tubes.
Glass Stir Rod
A glass rod is used to
manually stir solutions.
It can also be used to
transfer a single drop of
a solution.
Glass Tubing
• USED TO
TRANSFER
GASSES FROM
DIFFERENT
CONTAINERS
Funnel
A funnel is used
to aid in the
transfer of liquid
from one vessel
to another.
Bunsen Burner
Bunsen burners are used
for the heating of
nonvolatile liquids and
solids.
Ringstands and their Components
Ringstands are a safe and
convenient way to perform
reactions that require heating
using a Bunsen burner.
Ringstands and their Components
Iron Rings
Iron rings connect to a
ringstand and provide a
stable, elevated platform
for the reaction.
Ringstands and their Components
Utility Clamps
Utility clamps are used to
secure test tubes,
distillation columns, and
burets to the ringstand.
Litmus Paper
Red litmus paper is
used to identify
bases.
Blue litmus paper is
used to identify
acids.
• AIM: How do we take measurements in
Life Science?
• Do Now: Take Plant measurements
• Homework: Data table and graph handout
What is the Metric System?
• The metric system is
a system of
measurement that is
based on the
number ten
• It is often used in
science and in
countries around the
world
How is it different?
• The metric
system uses
meters, grams,
liters and Celsius
• The English
System uses feet,
ounces, gallons
and Fahrenheit
What can be measured?
• The metric
system can be
used to measure
mass, volume,
length, and
temperature
Anyone want to work
for me this weekend
What are units? •Words used to describe numbers
•Example:
meters, liters, grams, %, $…
What are…
Units
Tools
1. Length
Meter (m) Metric ruler
2. Volume
Metric ruler or
Liter,
mL graduated cylinder
Triple-beam
Grams (g)
balance
g/ml or g/cm3 Tools for mass &
volume
3. Mass
4. Density
5. Temperature
cm3 =
ºC or K
thermometer
What is matter?
• Anything that has mass &
takes up space
• Examples:
Solid, Liquids, & Gases
What is mass?
• Mass is the amount of matter in
an object
• Triple beam balance is used to
measure mass
• Measured in grams
What is weight?
• Weight is the amount of gravity
that acts upon an object
Are mass and weight the same?
• Mass and weight are different.
• Mass is the amount of matter in an
object and weight is determined by
the amount of gravity and matter
in an object.
• This is why your weight changes on
different planets
What is volume?
• Volume is the amount of space
an object occupies
What is length?
• Length is the
distance between
two points
What is temperature?
• Temperature is the average
motion of particles
• We can relate this motion to how
hot or cold it is.
What is density?
• Density is how much mass an
object has in a given space.
• The formula for density is:
Density
=
_ Mass__
Volume
How do we measure length?
• Length is measured using a
metric ruler or meter stick
• The metric units for length
are the meter (m),
centimeter (cm), and the
millimeter (mm)
How do we measure volume?
• We use a graduated cylinder for liquids
• We use a ruler for rectangular solids
(L x W x H)
• We use the water displacement method to
determine the volume of irregularly shaped
objects
• The metric units for volume are the liter
(L), the cubic centimeter (cm³), and the
milliliter (mL)
Volume of a liquid
• Measured with a Graduated Cylinder,
Beaker or Erlenmeyer flask
• Measured in Liters
The amount of space an object takes up
Graduated Cylinder
mL
Volume of a solid
• Calculated
– Length x width x height
• Measured in units3
Metric ruler
Length x Width x Height (L x W x H)
Volume Displacement
1. Add at least 20 mL of water to
graduated cylinder.
2. Place the object in the water.
3. Note where the water level rises & then
subtract:
Final Water Level - Initial Water Level =
Volume of the Object
50 mL
55 mL
5 mL
How do we measure mass?
• Mass is measured by using a
balance
• The metric units for mass are the
gram (g), and kilogram (kg)
The amount of matter in a given object
Triple-beam balance
Grams (g)
mg
499 g
578.6 g
389.3 g
How do we measure temperature?
• Temperature is
measured using a
thermometer
• The metric unit
for temperature
is Celsius (°C)
Length
Liter
Gram
ºC
Metric Ruler
Volume
Triple-beam balance
Temperature
Mass = The amount of matter in an object
Weight = The gravitational pull on the mass of an object