Elodia is a plant that lives in water. Like all plants, elodea can make its own food via photosynthesis. Oxygen is a gas produced during photosynthesis. Photosynthesis can only happen in the presence of light. To measure the rate of photosynthesis, a piece of elodia can be placed in an inverted test tube filled with sodium bicarbonate solution. Oxygen gas produced by photosynthesis will collect at the top of the tube. The experimental set up created by a student is shown above. What is the dependent variable in this experiment?

Photosynthesis is the only dependent variable

Explanation:

oxygen is a gas produced by photosynthesis

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.