Answer:
Bacteria
Explanation:
Bacteria are a group of single celled organisms that are neither plants or animals.
Bacteria lack cell organelles such as the nucleus and the chlorophyll.
They can be found in many environments and most of them are adapted to survive in extreme environments such as hot-springs where the temperatures are extremely high.
Unlike the plant cell wall, bacterial cell wall has a layer of peptidoglucan which determines their shape. Their cytoplasm contains both DNA and RNA.
They have sharp teeth up to 3 inches long and they are big
DNA replication needs to occur because existing cells divide to produce new cells. Each cell needs a full instruction manual to operate properly. So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!