An ameba is a single-celled, heterotrophic organism. in order to meet its energy needs, it relies directly on the interaction of which cell structures?

Cell membrane and mitochondria.

Explanation:

The cell membrane and mitochondria helps the amoeba to gain energy. The food is engulfed inside the amoeba by the false foot.

The cell membrane folds itself and and traps the food particle which gets inside the cell.

The food is converted into ATP inside the mitochondria which provides energy to amoeba for the proper functioning.

hence, the correct answer is Cell membrane and mitochondria.

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.