Objective: How Does Fatigue Affect Muscle Performance?
Key Words: fatigue, squeeze, homeostasis, claim, evidence, fact
Do Now:
Read the paragraph and answer the two questions
below.
What causes fatigue?
A condition know as muscle fatigue occurs when
certain waste products of muscle cell activity
build up in the cells. Until these waste chemicals
are removed, the fatigue will continue.
• What is another word to describe “fatigue”?
Tiredness
• Why “rest” help recover from fatigue?
Rest allows the body to remove waste chemicals from cells
Objective: How Does Fatigue Affect Muscle Performance?
Key Words: fatigue, squeeze, homeostasis, claim, evidence, fact
Do the Following Activity
• Hold a spring-type clothespin between your thumb and index
finger.
• Pinch the ends together completely (until the two ends touch)
and release them.
• Do this as rapidly as possible for one minute.
• Record the number of times you could squeeze the clothespin
in one minute: __________
• Try the activity again, doing it the same way and using the
same two fingers as before.
• Record the number of times you could squeeze the clothespin
the second time:__________
Objective: How Does Fatigue Affect Muscle Performance?
Key Words: fatigue, squeeze, homeostasis, claim, evidence, fact
Answer the Following Questions
1. Some people are able to squeeze the clothespin more
times in a minute than others.
Suggest a possible explanation for this.
Having stronger muscles or better fine motor skills
2. Could you do as many in a minute the second time as you
could do the first time?
Provide a biological explanation for these results
If yes, first time squeezing the clothespin increased pulse rate, then second time
muscles gets more oxygen and nutrients, and have more energy.
OR
If not, first time squeezing took energy away for the muscles, then second time
muscles gets less oxygen and nutrients, and have less energy.
Objective: How Does Fatigue Affect Muscle Performance?
Key Words: fatigue, squeeze, homeostasis, claim, evidence, fact
Objective: How Does Fatigue Affect Muscle Performance?
Key Words: fatigue, squeeze, homeostasis, claim, evidence, fact
Part A. Questions
1. What does an increased pulse rate indicate about the heart rate and flow of blood in
someone’s body?
An increased pulse rate indicates that the heart will beat faster so the blood will flow more
rapidly
2. When muscles are active, cells use nutrients and oxygen at a higher rate and
produce waste chemicals and heat more rapidly.
Describe how the interaction of two or more body systems helps to maintain homeostasis
during periods of high muscle activity.
The circulatory system: the heart pumps faster, so more glucose and nutrients will be
delivered to the muscles.
The respiratory system: the lungs breathe more rapidly, so more oxygen is taking
in and carbon dioxide taking out.
Objective: How Does Fatigue Affect Muscle Performance?
Key Words: fatigue, squeeze, homeostasis, claim, evidence, fact
3. A student in your class suggests that when most people watch exciting sporting events on
television, their pulse rates increase.
What is a reliable way to find out if this statement is correct?
By designing a control experiment or an investigation
4. What specific evidence would you need in order to determine if what the student suggests
in question #3 can be supported?
You need to measure the pulse rate in different scenarios:
a. When people are watching exciting sporting events on TV
b. When people watch other kinds of programs on TV
Objective: How Does Fatigue Affect Muscle Performance?
Key Words: fatigue, squeeze, homeostasis, claim, evidence, fact
5. If you wanted to increase your clothespin-squeezing rate, would you suggest exercising or
resting before you did it?
Explain why you think your choice is the correct one
I would suggest exercise first because it produces a faster pulse rate,
which indicates that the blood is getting to the muscles faster.
OR
I would suggest relax first because exercise takes energy away from the muscles
and a person who has been resting will have more energy.
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
Investigating Claims
Student A claims that a person will be able to squeeze a clothespin more times in a minute
if the person exercise first. Student A suggests that exercising produces a faster pulse rate,
which indicates that the blood is getting to the muscles faster.
Student B claims that a person will be able to squeeze the clothespin more times in a
minute if the person does not exercise first. Student B suggests that exercise takes energy
away from the muscles, and a person who has been resting will have more energy.
•Which of the two students do you agree with?_______
•How could you find out for sure which claim is correct?
By designing a control experiment or an investigation
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
Design an Experiment
• You must now design and conduct a controlled experiment to
gather evidence that will determine which of the two claims is
correct.
• Be sure your experimental methods will provide enough data
upon which to base a valid conclusion.
• You will have to conduct several trials.
• Your report must include the following parts.
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
1. Problem
• Determine the question you are trying to answer
• Use the format:
“What is the effect of ___________
on _____________________?”
• Student A:
exercise first
What is the effect of _______________
clothespin squeezing rate
on _____________________________?
• Student B:
resting first
What is the effect of _______________
clothespin squeezing rate
on _____________________________?
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
2. Hypothesis
• The hypothesis is a tentative statement about the expected
relationship between the variables.
• Use the format:
“If _____________________________
Then ___________________________”
Student A:
If somebody exercises first
then she will increase the clothspin squeezing rate
Student B:
If somebody rests first
then she will increase the clothspin squeezing rate
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
3. Variables
• Your independent variable is the variable you chose to test in your
experiment.
• Your dependent variable is the variable you measure in your
experiment.
• The independent variable is ____________________________
exercise first / resting first
• The dependent variable is ______________________________
clothespin squeezing rate
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
4. Design of the Experiments
•Explicit the independent and dependent variables. (10 credits)
• Your independent variable is the variable you chose to test in your
experiment.
• Your dependent variable is the variable you measure in your experiment.
•Describe your experimental group in at least four steps. (10 credits)
•Describe your control group in at least four steps. (10 credits)
•
•
•
•
Decide how many individuals you will test,
What you will have them to do
How many trials you will conduct with each
How the control and experimental group differ
•List the materials you need to conduct your experiment (5 credits)
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
4. Design of the Experiments
Experimental Group
1.
Take ____students.
2.
Let them exercise first by (doing something)___ for (how long)___
3.
Ask them to hold a clothespin between their right thumb and index
finger. Ask them to pinch the ends together and release them.
4.
Count ______________________________________________
5.
Rest for _____ minutes.
6.
Repeat the experiment _______times.
Control Group
1.
Take ____students.
2.
Let them rest first for (how long) ________________
3.
Ask them to hold a clothespin between their right thumb and index
finger. Ask them to pinch the ends together and release them.
4.
Count ______________________________________________
5.
Rest for _____ minutes.
6.
Repeat the experiment _______times.
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
5. Observation Data table
Design a data table to record your observations
Control Group: Clothespin Squeezing Rate after _______________
Student’s
Name
Trial #1
Trial #2
Trial #3
Average
Experimental Group: Clothespin Squeezing Rate after __________
Student’s
Name
Trial #1
Trial #2
Trial #3
Average
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
6. Observations
Organize and graph your data using a line graph
Average Clothespin Squeezing Rate (times/min)
•
Average Clothespin Squeezing Rate of Students in class
After Exercise
After Resting
Edwin
Lin Han
Students
Adeb
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
7. Conclusion
• Review your hypothesis
• Explain your conclusion based on your observations and your
knowledge.
• My hypothesis is (true or false).
• According to my data _____________________________
• One possible explanation of my conclusion is __________
• This investigation has been performed by….
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
Making Connection Lab - Rubric
Items
Your
Grade
Teacher’s
Grade
1. Problem: Over 10 credits, you got:


The problem clearly determined the question you are trying to answer.
The problem is stated using the format:
“What is the effect of ___ on __________?”
2. Hypothesis: Over 10 credits, you got:


The hypothesis is a tentative statement about the expected relationship between the variables.
The hypothesis uses the format:
“If _______________ then _______________________”
3. Design of your experiment:





The independent variable is explicitly included (5 credits)
The dependent variable is explicitly included. (5 credits)
The experimental group is described in at least four steps. (10 credits)
The control group is described in at least four steps. (10 credits)
Both groups include

How many individuals you will test

What you will have them to do

How many trials you will conduct with each
The materials you need to conduct your experiment are listed (5 credits)
Observation:


Design one o more data tables that you will use to record the data (10 credits)
Plot your data in a bar-graph to summarize the data for easier understanding of what you found (10
credits)
State a conclusion:

Note whether you data supports or refuse your hypothesis (5 credits)

Include an explanation of how or why this conclusion follows from the data you collected. (5 credits)
Presentation:

The report is clear and concise, well written in proper English ( 10 Credits)

The presentation is neat and creative (5 credits)
Your total grade is
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
1.Correctly state the problem being debated in this research.
Remember this needs to be in the form of a question.
What is the effect of doing 50 jumping jacks
on the rate of squeezing a clothespin in one minute?
2. Using the correct format for stating a hypothesis, correctly state a hypothesis
for this experiment.
If I do 50 jumping jacks
Then I will squeeze a clothespin more times in one minute
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
3. Design a procedure using a minimum of five steps that could test this
proposal.
Experimental group:
1. Collect the materials: clothespins and stop watchers.
2. Ten people do 50 jumping jacks
3. They squeeze a clothespin for a minute
4. They measure the number of times they pinch the clothespin
5. Repeat the experiment 5 times and calculate the average
Control group
6.The same procedure as before, but they rest before squeezing
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
4. Explain what is meant by the independent variable
Independent variable is the variable you choose or test in the experimental group
5. What is the independent variable in this experiment?
The independent variable is to do 50 jumping jacks
6. Explain what is meant by the dependent variable
Dependent variable is the variable you measure in both the experiment and
control groups.
7. What is the dependent variable in this experiment?
Dependent variable is the number of time people squeeze a clothespin in
one minute
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
8. Explain what is meant by a control
Control is the experiment set up without independent variable.
9. What is the control in this experiment?
The control is the experiment in which people relax before squeezing
10. State or present data that will support your hypothesis for this experiment.
Draw a data table if you wish
Groups
1
2
3
4
Average
Control
Experimental Group
People who did jumping jacks before
squeezing were able to squeeze ____
times (___) than people who rested
before squeezing (___)
Objective: Design an Investigation to Support or Refute a Claim
Key Words: Claim, evidence, fact, hypothesis, variable
4. Conduct your experiment (5 credits)
• Gather the materials you will need, arrange for your “test subjects” and do the
experiment
5. Observation: Data table & Graph (20 credits)
• Design one o more data tables that you will use to record the data (10 credits)
• Plot your data in a bar-graph to summarize the data for easier understanding
of what you found (10 credits)
6. State a conclusion (10 credits)
• Note whether you data supports or refuse your hypothesis
• Include an explanation of how or why this conclusion follows from the data
you collected.
• The report is well written in proper English (10 Credits)