Living things obtain and use energy so alive?
The cell is fundamental unit of structure and function in living organisms .All cells arise from pre-existing cells by division . The cell theory states that the cell is the basic unit of life and that all other cells are developed from an existing cell. This theory was developed way back in the mid of 17th century.
Birds, just like humans, have a four-chambered heart.
The Kingdom Protista has a bunch of organisms thrown into the category because scientists have yet to sort them out properly. In the future these classifications might become more specific.
