What is a fossil? an animal or plant that is extinct the bones of a dead organism an animal or plant that cannot evolve the remains of an ancient organism

Which of these organisms have the greatest amount of cell specialized

I’m doing some practice exam questions for biology, and i’m not sure how to do these 3 parts to the question.

Match the examples to the correct level of organization. 1. system level roses, snakes, puppies 2. organism level roots, stamens, leaves 3. tissue level bone, cartilage, blood 4. organ level heart, veins, arteries