Which statement accurately describes an organ?

An organ is accurately described as being made of different tissues working together. This means that an organ consists of multiple types of tissues, each contributing specialized functions that allow the organ to perform its specific role in the body. For instance, the heart is made up of muscle tissue, connective tissue, and nervous tissue, all of which work together to pump blood throughout the body effectively.

The other choices do not accurately capture the complexity of an organ. A collection of similar cells refers to tissue, which is a level of organization below that of an organ. An individual cell is the most basic unit of life, while a single type of tissue is also a distinct entity but not sufficient to constitute an organ. Understanding the hierarchical structure of biological organization—cells, tissues, organs, and systems—helps clarify how diverse components function collectively within living organisms.