<span>B. Covalent bonds because the carbon likes to share its electrons with the hydrogen atoms</span>
No, it is nowhere near "homeostasis." Perhaps it is a homeostatic mechanism or a natural immunological response of the body.
No, because there is only so much food for them to eat.
The same applies for all levels of the food chain.
External respiration (correct answer) involves the exchange of oxygen and carbon dioxide within the environment.
The exchange of wastes through the skin is just called excretion by sweating.
There is no exchange of nutrients that occur in the lungs but rather absorption of nutrients is the function of the gastrointestinal tract.
The exchange of oxygen and carbon dioxide within the cell is called cellular respiration and involves carrying oxygen from the blood to the cell then the cell uses it as the final electron acceptor in the electron transport chain. The metabolic wastes of the cell, primarily carbon dioxide, goes now to the bloodstream to be exchanged for oxygen in the lungs.
