Activity 1:  Independent & Dependent Variables

1. After reading about independent and dependent variables on Canvas, test your understanding by providing the independent and dependent variable for the following scenarios:

1.  Measuring temperatures of young adults and seniors to see if there is a difference based on age.

Dependent variable:                                        Independent variable:

• Determining if gender has an effect on % body fat of male and female students in the class.

Dependent variable:                                        Independent variable:

• Exploring the relationship between exam scores and the time spent studying.

Dependent variable:                                        Independent variable:

Activity 2:  Homeostasis

You are outside on a very cold day and your body temperature begins to drop below 36°C, falling outside the normal range.

 Fill-in the following, to show what occurs in your body to maintain temperature homeostasis.

            Normal range body temp:______________________­­­__           Set point:________________

­

Stimulus:__________________________________________________________________

(What is the stimulus in this scenario?)

Sensor:_______________________________

(What is the sensor for temperature in the body?)

Integrating center:______________________

(Which part of the body serves as the integrating center for temperature?) Be specific.

Effector(s):______________________________

(What is/are the effectors that can respond?)  Can you find two?

Response:_____________________________________________________________________

(What is the response of the effectors and how does this affect body temperature?)

Conclusions: Summarize what the purpose of this negative feedback mechanism is in the body.

List at least three other homeostatic conditions that humans must maintain other than temperature.

            1.

            2.

            3.

Activity 3:  Allometric Relationships

1.         Make an observation and form a hypothesis: Pick a body measurement from the list below that you believe corresponds to height. Then formulate a hypothesis that can be tested.

                    a) Observations: State one or more observations related to your scientific inquiry.

                Observation(s):

b) Hypothesis:Generate a hypothesis and include a justification for your hypothesis.

    Hypothesis:

2.         Collect Data: Place measurement date in the table below.

TABLE 1

Enter your individual data in the following google document https://docs.google.com/spreadsheets/d/1aJN8YOY1_uNTujiL_-dWexkZcpQEtyhm_sw9cldK8RU/edit?usp=sharing

3.         View Results: Create a scatter plot graph with trend line and R-squared value.

                        (Place graph here)

– Label the X-axis with your independent variable and include the correct units.

– Label the Y-axis with your dependent variable and include the proper units.

– Label your figure (graph) with an appropriate title.

4.         Statistical Analysis and Conclusion: Does the R-squared value support your hypothesis?  Explain your answer.

5.         List at least three possible sources of error for this experiment.  (Hint: Were there any parts of the experiment that needed more explanation or could have been done differently by different people?)