Answer:The main way animal-like protists differ from plant-like protists is in the way they get energy. Animal-like protists are heterotrophs. ... Plant-like protists, on the other hand, are autotrophs. They can make their own energy from the sun or other sources just as plants can.
Explanation:
Oxygen.
Oxygen was fatal when organisms started using photosynthesis, this event was known as the Great Oxidation Event.
Answer:
To study objects that are way too small
