Answer:
essential
Explanation: Amino acids are organic compounds composed of nitrogen, carbon, hydrogen and oxygen, along with a variable side chain group. Your body needs 20 different amino acids to grow and function properly. Though all 20 of these are important for your health, only nine amino acids are classified as essential
Answer:
Transportation of essential gases an nutrients, waste and unwanted products
Explanation:
the key feature of circulation is transportation of essential gases and nutrients around the body of an organism, removes unwanted products of metabolism from the tissues, and carries these products to specialized excretory organs, if present.
I would say either C or D
Hope this helps! :)
