I believe the answer you are looking for has to do with cells, they are the basic building block of life and are the smallest life that can support itself.
Answer: D
Explanation:
Many unicellular organisms live in bodies of water and must move around to find food. Most often, they must obtain nutrients by eating other organisms. Plant-like protists, and some types of bacteria, can make their own food through photosynthesis.
"Mechanical" would be the kind of reproductive isolation among the choices given in the question that has been observed in these two species. The correct option among all the options that are given in the question is the first option or option "A". I hope that the answer has come to your help.
Because they are prokaryotic cells.
Answer:
it could be more susceptible to disease or it could be D
