Answer: cell tissue organ and organ system.
Explanation:
Fossils only form if certain qualifications are met, and some organisms cannot meet them, so they just cease to exist, not a single sign of them. This could happen if they were organisms that decayed completely. Fossilization can include freezing, drying, and encasement, usually in tar or resin.
Producers, because they're the start of the food chain and without them there will be no food chain.
Explanation:
Your heart muscle cells –
