Question

select the correct answer: a marine biologist wishes to test the hypothesis that heavy grazing by fish causes the brown alga laminaria to stay short rather than grow upright. which of the following variables could be manipulated successfully at the shore to test this hypothesis? a. add nutrients to the ocean water around the algae to see if it will grow taller b. increase the amount of dissolved carbon dioxide in the water around the algae to see if they grow taller c. place a netted screen around the algae to restrict fish from grazing on the algae and check for any change in growth d. alter the intensity of light to see if this is the cause of the algaes stunted growth e. protect the algae from ocean waves to see if wave shock is causing the stunted growth

Explanation:

The hypothesis is about fish - grazing affecting algae growth. Option C directly manipulates the fish - grazing variable by restricting fish access to the algae, which is relevant to testing the given hypothesis. Other options (A - nutrients, B - carbon dioxide, D - light intensity, E - wave shock) manipulate variables not related to fish - grazing.

Answer:

C. place a netted screen around the algae to restrict fish from grazing on the algae and check for any change in growth