Lab 1 Report Sheet Name Team No.

Heart Rate, Cardiovascular Fitness

and the Scientific Method Date Lab Section

Biology 100 – K. Marr

Prelab Questions

Instructions

Read the handout on the Scientific Method before attempting to answer the questions that follow! Be prepared to hand in and discuss these questions at the start of your lab session.

Major Components of an Experiment: Complete the following statements.

  1. The variable that the investigator varies in the experiment (e.g. humidity, temperature, concentration, etc.) is called the______variable.
  1. The variable that the investigator measures, counts, or observes is called the______variable.
  1. Variables that are held constant during an experiment so that they don’t impact the results of are known as ______variables.
  1. The treatment that removes the independent variable or sets at its standard value is known as a ______.
  1. A tentative answer to a question is called a ______.

Scientific Questions: Which of the following are scientific questions that can be answered using the Scientific Method? Indicate your response by circling yes or no before each question. Briefly explain how you came to your decision in each case.

6.  Scientific Question: Yes or No? Do childhood immunizations cause autism is some children in the United States? Explanation:

  1. Scientific Question: Yes or No? Did the 60 year-old man develop skin cancer on his nose because he did not use sun screen as a teenager? Explanation:

Developing Hypotheses:

  1. Restate each of the following hypotheses as “If..., then...” statements

a.  Hypothesis: Students that attend class regularly usually get better grades than those with poor attendance.

b.  Hypothesis: The application of fertilizer to apple trees each spring may result in better apple production.

  1. Write a testable hypothesis for the following question using the “If... then...” format. Why is the rate of skin cancer higher today than it was 100 years ago?

Independent Vs Dependent Variables

Identify the independent and dependent variables in the following experiments

10.  Your body weight measured daily for 30 days

a.  Dependent variable: ______

b.  Independent variable: ______

11.  Your body temperature three hours after taking two ibuprofen tablets

a.  Dependent variable: ______

b.  Independent variable: ______

Control Treatment: Suggest a control treatment for each of the following experiments.

12.  Ten pea plants are sprayed with a plant growth hormone dissolved in alcohol and their height measured daily for two weeks after the spraying.

Control treatment:

13.  Your pulse rate is determined after 4 minutes of aerobic exercise. (Hint: the control is what the heart rate after exercise will be compared to.)

Control treatment:

Line vs. Bar Graphs: Indicate if the data obtained in the following experiments should be plotted as a line graph or a bar graph. Briefly explain your reasoning.

14.  Number of coddling moths visiting the yellow, blue, and green pheromone traps.

Line graph or Bar Graph? (circle one) Why?

15.  Pea plant height measured daily for 10 days.

Line graph or Bar Graph ? (circle one) Why?

Instructions: Neatly complete table 5 on the following page as your team conducts the experiment during your scheduled lab period.

Biology 100 – K. Marr – Revised Winter 2008 Lab 1 Report Sheet – Page 8 of 13

Table 5. Class Results

Team
No. / Test
Subject / Personal Data / Experimental Data (bpm = beats per minute; fp = fitness points)
Gender / Age (years)
(check the appropriate box) / Exercises regularly / Smoker / BMI / Standing Resting HR / Reclining HR / Reclining to standing / HR after step test / Total Fitness Points
M / F / < 18 / 18-20 / 21-25 / 26-30 / 31-35 / >35 / Yes / No / Yes / No / bpm / fp / bpm / fp / bpm / fp / bpm / fp
1 / 1
2
3
4
2 / 1
2
3
4
3 / 1
2
3
4
4 / 1
2
3
4
5 / 1
2
3
4
6 / 1
2
3
4
Class Average

Biology 100 – K. Marr – Revised Winter 2008 Lab 1 Report Sheet – Page 8 of 13

Analysis of the Data

The following exercises will allow you to practice writing and answering scientific questions, writing hypotheses to answer these questions, and using the data in Table 5 to test these hypotheses. Exercise 1 will serve as a model for writing a scientific question and a hypothesis in the “If ….., the ……” format.

Exercise 1. Examining the Effect of Gender, exercise and smoking on Cardiovascular Fitness

a)  The Question: On average, which factor, gender, exercise or smoking has the greatest effect on cardiovascular fitness in this class?

b)  Hypothesis #1: If exercise has the greatest impact on cardiovascular fitness, then the test subjects that exercise regularly will on average have more total fitness points than test subjects that do not exercise.

Hypothesis #2: If smoking has the greatest negative effect on cardiovascular fitness, then

c)  Graph the Data: Use the data in table 5 and the grid below to construct a graph that shows the relationship between the dependent and independent variables in the two hypotheses, above. Include all of the following on the same graph: average total fitness points for males and females, smokers and nonsmokers and test subjects that exercise regularly and those that do not exercise. Should the data be plotted as a bar graph or line graph? Look at the variables involved—are they discrete or continuous variables? See the handout on the Scientific Method for tips on how to make a proper graph. Ensure that each axis is labeled fully (including units of measure), and compose an informative title for this figure in the space provided below the grid.

Note: You may use a graphing program (e.g. Excel) to plot the data as outlined above. If you use a graphing program, after printing, cut and tape the graph to fit in the space below.

Figure 1. ______


Exercise 1 (cont)—effect of gender, smoking and exercise on cardiovascular fitness

Evaluate the Hypotheses: Use complete and well articulated sentences to answer the following questions.

d)  Narrative Summary. Write a paragraph that summarizes the results displayed in your graph (fig. 1) on the previous page. Use specific numerical data from your graph on the previous page as part of your response.

e)  Does the class data support or refute Hypothesis #1? Explain fully. Use specific numerical data from your graph on the previous page to support your response.

f)  Does the class data support or refute Hypothesis #2? Explain fully. Use specific numerical data from your graph on the previous page to support your response.

Exercise 2. Is there a relationship between BMI and cardiovascular fitness in this class?

a)  Propose a testable hypothesis of the “If....., then.....” variety used in Exercise 1 to answer the question above.

b)  Graph the Data: Use the data in table 5 and the grid below to construct a graph that shows the relationship between the BMI and total fitness points for all test subjects. Consider the following questions when designing the graph: Is BMI or total fitness points the independent variable? Should the data be plotted as a bar graph or line graph? Look at the variables involved—are they discrete or continuous variables? Ensure that each axis is labeled fully (including units of measure), and compose an informative title for this figure in the space provided below the grid.

Note: You may use a graphing program (e.g. Excel) to plot the data as outlined above. If you use a graphing program, after printing, cut and tape the graph to fit in the space below.

Figure 2. ______


Exercise 2 (cont)—relationship between BMI and cardiovascular fitness

Evaluate your Hypothesis: Use complete and well articulated sentences to answer the following questions.

c)  Narrative Summary. Write a paragraph that summarizes the results displayed in your graph (fig. 2) on the previous page. Use specific numerical data from your graph on the previous page to support your response.

d)  Does the class data support or refute your hypothesis? Explain fully. Use specific numerical data from your graph on the previous page to support your response.

e)  According to the class data, is what is the relationship between BMI and cardiovascular fitness? Explain fully. Use specific numerical data from your graph on the previous page to support your response.


Exercise 3. Is there a relationship between age and cardiovascular fitness in this class?

a)  Propose a testable hypothesis of the “If....., then.....” variety used in Exercise 1 to answer the question above.

b)  Graph the Data: Use the data in table 5 and the grid below to construct a graph that shows the relationship between the age and average total fitness points for each age group. Consider the following questions when designing the graph: Is age or total fitness points the independent variable. Should the data be plotted as a bar graph or line graph? Look at the variables involved—are they discrete or continuous variables? Ensure that each axis is labeled fully (including units of measure), and compose an informative title for this figure in the space provided below the grid.

Note: You may use a graphing program (e.g. Excel) to plot the data as outlined above. If you use a graphing program, after printing, cut and tape the graph to fit in the space below.

Figure 3. ______


Exercise 3 (cont)—relationship between age and cardiovascular fitness

Evaluate your Hypothesis: Use complete and well articulated sentences to answer the following questions.

c)  Narrative Summary. Write a paragraph that summarizes the results displayed in your graph (fig. 3) on the previous page. Use specific numerical data from your graph on the previous page to support your response.

d)  Does the class data support or refute your hypothesis? Explain fully. Use specific numerical data from your graph on the previous page to support your response.

e)  According to the class data, is what is the relationship between age and cardiovascular fitness? Explain fully. Use specific numerical data from your graph on the previous page to support your response.


Exercise 4. Which team in the class has the best cardiovascular fitness?

a)  Graph the Data: Use the data in table 5 and the grid below to construct a graph that shows the relationship between the average total fitness points for each team in this class. Consider the following questions when designing the graph: Is team number or total fitness points the independent variable. Should the data be plotted as a bar graph or line graph? Look at the variables involved—are they discrete or continuous variables? Ensure that each axis is labeled fully (including units of measure), and compose an informative title for this figure in the space provided below the grid.

Note: You may use a graphing program (e.g. Excel) to plot the data as outlined above. If you use a graphing program, after printing, cut and tape the graph to fit in the space below.

Figure 4. ______


Exercise 4 (cont)—which teach has the best cardiovascular fitness

Analysis of the Data: Use complete and well articulated sentences to answer the following questions.

b)  Which team has the best cardiovascular fitness? The worst cardiovascular fitness? Use specific numerical data from your graph (fig. 4) on the previous page to support your response.

c)  Analyze the Personal Data in Table 5 for the most and least fit teams in the class. Which factor(s) were most important in determining cardiovascular fitness for each team? Explain fully. Use specific numerical data from your graph on the previous page to support your response.

Exercise 5. Weaknesses in the experiment—are there any variables that were not controlled?

What weaknesses or flaws do you see in this experiment that might have an impact on the validity of the results and conclusions? Suggest ways the experiment could be improved to correct for each of the weaknesses or flaws. Record your responses on in the table below

Weaknesses in Experiment / Improvement
1.
2.
3.
4.

Exercise 6. Additional hypotheses and the next experiment

Suggest additional and/or modified hypotheses that might be tested and briefly describe what the next experiment might be.

Application and Review Questions

  1. Samples of the freshwater algae Elodea from Lake Tapps were placed in 0.5%, 1.0%, 1.5%, and 2.0% salt solutions and then examined under the microscope to determine the effect the salt solutions have on the Elodea cells. What would be a suitable control treatment for this investigation?
  1. Why is it important that an experiment has only one independent variable?
  1. Can an experiment have more than one dependent variable? Explain and give an example.

3. a) For the class, on average how did the heart rate change after moving from a standing position to a reclining position? Use specific numerical data to support your response.

b) How do you account for this change? (Hint: don’t forget about gravity!)

  1. Current research indicates that most heart attacks occur as people get out of bed after a night’s sleep. Account for this observation in light of your experimental findings in this experiment. ? (Hint: don’t forget about gravity!)
  1. Why would athletes need to work longer and harder than the average person before their heart rates were at the maximum value?
  1. Why is science said to be “self-correcting”?

Biology 100 – K. Marr – Revised Winter 2008 Lab 1 Report Sheet – Page 8 of 13