Answer:
B. interconnected
Explanation:
All the systems in our bodies (humans are indeed animals) are connected with each other to create a functional being. The blood flows throughout the body, providing nutrients; the bones support the structure and protect the heart and lungs. They work together.
Why not A: The systems are all completely necessary. There's nothing extraneous in our bodies, because extraneous stuff takes up energy, and our biology is incredibly economical.
Why not B: They're not interchangeable. How would you like your bones to turn to blood? Uh-huh.
Why not D: They interact with each other consistently, so they're not separate or segregated.
Fossils best demonstrate what ancient organisms may have looked like when they lived long ago. Without fossils, knowing such things would be nearly impossible.
Answer: True.
Explanation: Cellular respiration can occur both aerobically (using oxygen), or anaerobically (without oxygen). During aerobic cellular respiration, glucose reacts with oxygen, forming ATP that can be used by the cell. ... In cellular respiration, glucose and oxygen react to form ATP.
