Answer:
D
Explanation: it's maintained by physiological processes
It is called socializing for the fishes & their groups are called schools
Answer:
The levels, from smallest to largest, are: molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere.
Answer: it's because they need to provide a lot of energy.
Explanation: fat cells have many mitochondria because they store a lot of energy. Muscle cells have many mitochondria, which allows them to respond quickly to the need for doing work.
