Proteins or polypeptides. (They are interchangeable)
Answer:
wrong, it's D. deoxygenated blood has lower levels of oxygen inside of it compared to oxygenated blood
Explanation:
Deoxygenated blood is blood with low levels of oxygen that flows toward the heart. Oxygenated blood if blood with high levels/exposure to oxygen that flows away from the heart.
Although A is true, it doesn't explain the difference, more like a fact.
Explanation:
our chemical barriers protect almost every infection we can get in our body
