1. natural selection acts on existing traits because you can not evolve into something you didn't have
2. original structures evolve to accomplish new function in order to survive
Answer:
The widest part of the body is below the middle. The body of a paramecium is asymmetrical. It has a well-defined ventral or oral surface and has a convex aboral or dorsal body surface. Its whole body is covered with a flexible, thin and firm membrane called pellicles.
Explanation:
Involuntary, meaning things in the body such as your heart is all regulated to act unconsciously while also receiving directives from the brain.
B) Geologic.
Hope this helps~!
~{Isle of flightless birds}