Professor tan studies water quality in streams near chemical plants. which is a type of qualitative data that professor tan should record during these studies?

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.

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.

your answer is going to be physical weathering