I believe the 3 main parts that make a virus would be its Nucleic content - DNA and or RNA, A protein coat surrounding the nucleic acid called a capsid, and the tail used for injecting viral genome into the host cell.
Organisms obtain energy from the foods
They're the only vein that carries oygenated blood
Answer:
If the animal shows it often like a color change or a slightly bigger or smaller body part
Explanation:
