Answer:
Tissues make up organs, together organs make up organs systems.
Explanation:
Cell is the basic unit of living system. In complex organism, cells with similar characteristics are organized into tissues that have common function. There are four main types of tissue: epithelial, muscular nervous and connective.
Different types of tissues are combined into specialized structures-organs, which then group together into organ systems. Some of the organ systems are: digestive, respiratory, excretory, endocrine etc.
