Mycorrhizae are symbiotic associations between some fungi and the roots of many plants. Which of the following experiments best would test whether a plant benefits from the presence of the fungus?
A) Grow many individuals of Plant X with two different species of fungi. Then compare the average plant size and average number of seeds produced between the two groups.
B) Grow many individuals of Plant X and Plant Y without any fungus. Then compare the average plant size and average number of seeds produced between the two groups.
C) Grow many individuals of Plant X in shaded and unshaded conditions. Then compare the average plant size and average number of seeds produced between the two groups.
D) Grow many individuals of Plant X with and without its fungus. Then compare the average plant size and average number of seeds produced between the two groups.

Question

Quizplus · Accepted Answer

Experiment D directly tests the impact of the fungus on Plant X by comparing the growth and reproductive output of plants with and without the fungus, isolating the variable of fungal presence.

Mycorrhizae Are Symbiotic Associations Between Some Fungi and the Roots