Question

1. read the description of a laboratory investigation below and then answer the following questions. an experiment was designed to investigate the effect of caffeine on the heart rate of canaries. 60 canaries were gathered. all canaries lived in the same environment and received the same amount of water, the same amount of food, and the same type of food every day. all canaries were the same age, biological sex, and size. however, half the canaries were given caffeine and the other half were not. the heart rate of the canaries was measured every hour for 8 hours.

a. what is the independent variable in this experiment? (1 pt)
b. what is the dependent variable in this experiment? (1 pt)
c. write a hypothesis for this experiment. (2 pts)
d. what is the control group in this experiment? (1 pt)
e. what is the experimental group(s) in this experiment? (1 pt)
f. list four constants in this experiment. (4 pts)
g. what type of graph would best represent the data from this experiment? (1 pt)

Explanation:

Step1: Identify independent variable

The factor being changed is caffeine - presence or absence.

Step2: Identify dependent variable

The variable that responds to the change is heart rate.

Step3: Write hypothesis

A possible hypothesis is that caffeine will increase the heart rate of canaries.

Step4: Identify control group

The group without caffeine is the control group.

Step5: Identify experimental group

The group with caffeine is the experimental group.

Step6: List constants

Environment, amount of water, amount of food, type of food, age, biological sex, size are constants. Four can be: environment, amount of water, amount of food, type of food.

Step7: Determine graph type

A line - graph would best show the change in heart rate over time for both groups.

Answer:

a. Presence or absence of caffeine
b. Heart rate of canaries
c. Caffeine will increase the heart rate of canaries.
d. Canaries not given caffeine
e. Canaries given caffeine
f. Environment, amount of water, amount of food, type of food
g. Line - graph