2.An organ system is made of a group of organs that are working to do a specific job.
An organ is made up of a group of tissues working together to do a specific job. Tissues are made of a group of cells that are similar and working together to do a specific job.(Like a pencil and a pencil case)
3/4.The body has levels of organization that build on each other. Cells make up tissues, tissues make up organs, and organs make up organ systems. The function of an organ system depends on the integrated activity of its organs. For instance, digestive system organs cooperate to process food.
