The endocrine system through the use of hormones
Answer:
The right answer is A
Explanation:
Because animals take in sugar and oxygen, break them down and release carbon dioxide and water along with ATP as usable energy.
Answer:
1. Providing structure --> Collagen makes skin strong yet flexible.
2. Maintaining homeostasis --> Insulin controls the concentration of sugar in the blood.
3. Fighting Disease --> IgA prevents the buildup of viruses and bacteria in the gut.
4. regulating chemical reactions --> Pepsin works in the stomach to speed up the breakdown of food.
