4. organism, organs, tissues, cells
The ultimate source of energy for most organisms is the Sun.
Answer:
D, loose hair.
Explanation:
If your hair is long enough, it could easily drift into the flame and catch on fire.
Answer:
The function of an organ system depends on the integrated activity of its organs. For instance, digestive system organs cooperate to process food. The survival of the organism depends on the integrated activity of all the organ systems, often coordinated by the endocrine and nervous systems.
Explanation: