Question

identify the independent variable in the following investigation. coral reefs compete for light and space with seaweeds that may cover the coral like a lawn. scientists measure the percent of coral covered with seaweed and the rate of coral growth in test plots with and without goby fish present. a) competition for light and space b) presence of goby fish in test plots c) coral reefs d) the percent of coral covered with seaweed and the rate of coral growth in test plots

Explanation:

The independent variable is the factor that is manipulated or changed in an experiment to observe its effect on the dependent variable. In this investigation, scientists are testing the effect of goby fish presence (by having test plots with and without them) on coral coverage and growth. So the independent variable is the presence of goby fish in test plots. Option a is the competition (not manipulated here), option c is the subject (coral reefs, not the variable being changed), option d is the dependent variable (what's being measured).

Answer:

b) presence of goby fish in test plots