Asnail, elodea (aquatic plant), or both were added to the tubes and they were stoppered. tubes were placed under a grow light for 24 hours and the results recorded. the test tubes were then covered for 24 hours to produce a dark environment and the results recorded. which statement best explains the change in test tube d from the light setup to the dark setup

The correct option is "The rate of photosynthesis decreased in the dark, thus the elodea used less CO2. The elodea and snails continued to produce CO2 through cellular respiration, raising the level of CO2 in the tube, causing the solution to become more acidic (yellow)."

Explanation:

The process of photosynthesis is dependent on light energy. As the test- tubes were kept in the dark hence, the rate of photosynthesis  was minimal. Less carbon dioxide was used for this process by the elodea.

The process of cellular respiration is not dependent on light. Hence, both the snail and elodea will carry out respiration and release carbon dioxide. Due to this carbon dioxide, the solution will turn acidic.

Adenine (A) and Thymine (T) produces a dark band on the chromosomes.It is in this region that dye stains of chromosomes that are rich in these base pairs.
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