Some scientists think that complex eukaryotic cells formed from the Union of two separate prokaryotic cells. The engulfing or one prokaryotic cell by another is a plausible explanation of why A eukaryotic cells lack the defense mechanisms of prokaryotic cells. B eukaryotic cells don't share any similarities with prokaryotic cells. С organelles in a eukaryotic cell work cooperatively D organelles in a eukaryotic cell would attack other cells. Time Remaining 1 hour 15 minutes​

hello there the answer is d

the most common energy conversion is from kinetic energy to potential energy, and then from potential energy to kinetic energy.

later on comes the heat energy, mechanical energy, and other energy conversions.

this energy conversion is so common that we can find it in our day to day lives as well.

- one of the most common energy conversions involves the changing of potential energy to kinetic energy or kinetic energy to potential energy

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link: