In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Question: Plant cells have structures that animal cells? Answer: lack
Plant cells have structures that animal cells lack.

Question: Trees release what gas as a byproduct of photosynthesis, thereby facilitating human respiration? Answer: oxygen
Trees release oxygen gas as a byproduct of photosynthesis, thereby facilitating human respiration.

Question: What term describes the overall ability of an animal to survive and produce offspring? Answer: fitness

The term fitness describes the overall ability of an animal to survive and produce offspring.