Question

A student set up an experiment to show the effect of light color on photosynthesis in Elodea plants. She filled three test tubes with distilled water and placed a piece of Elodea in each of the tubes. She added a drop of phenol red, which turns red in a basic solution and yellow in an acidic solution. She blew in each tube to add carbon dioxide, which caused the distilled water to become more acidic so the phenol red turned yellow. She exposed Tube A to white light, Tube B to green light, and Tube C was wrapped in aluminum foil. Which of the tubes should she expect to turn red the fastest?

Answer 1

Answer:

Tube A will turn red the fastest.

Explanation:

• Tube A will turn red fastest because Elodea plants will take up the white light and carry out photosynthesis.

• In tube B, the red colour will not be generated fastly because plants do not use green light. Usually, the green light is just reflected by the plants and it is not absorbed.

• In tube C, no photosynthesis will be able to occur because due to the wrapped aluminium foil the plants could not receive any light for photosynthesis.