Answer - Well to put it in short terms.
Cells such as water cells or aquatic microorganisms need and required to have a large surface area increased. Because this helps them stay afloat without spending much amount of energy to float.
Answer:
This question has little context, but I understand what you are trying to say.
The reason why dark moths survived while light moths weren't able to survive is due to the dark moths having conditions that allowed them to camouflage better than the light moths. An environmental condition that would allow this would be the dark moths and the light moths living in the same dark environment.
Explanation:
This questions seems like its missing other parts