The functions of some proteins change depending on whether they are in the light or in the dark they are photoreceptive (PR) proteins. A team of scientists recently determined that PR proteins bind to DNA to regulate gene expression in microbes. Answer the following three questions about this scenario.
-Suppose that the team of scientists conducted the following experiment: They mixed the PR proteins with DNA in a test tube and measured the amount of protein that bound to the DNA after 10 minutes under variable amounts of light. What was the independent variable in their experiment?
A) the amount of light that they exposed the test tube to
B) the amount of PR proteins bound to DNA
C) the type of PR proteins used in the experiment
D) the amount of time the light was exposed to the test tube

Question

Quizplus · Accepted Answer

The independent variable is the amount of light that they exposed the test tube to, as they are measuring the amount of protein that binds to DNA under variable amounts of light. The amount of PR proteins bound to DNA, the type of PR proteins used in the experiment, and the amount of time the light was exposed to the test tube are not being varied in this experiment.

The Functions of Some Proteins Change Depending on Whether They