What is a collection of similar cells that perform a particular function?

A collection of similar cells that perform a particular function is referred to as tissue. In the context of biology, tissues are groups of cells that work together to carry out specific tasks, and they are one of the fundamental building blocks of more complex organisms. For example, muscle tissue is composed of muscle cells that enable movement, while epithelial tissue serves as a protective layer covering surfaces and cavities.

In contrast, the other terms in the choices have distinct meanings. An organ consists of multiple types of tissues that collaborate to perform a specific function within the body, such as the heart or liver. A body system, on the other hand, is a higher level of organization and refers to a group of organs that work together to accomplish a complex function for the organism, such as the cardiovascular system. Systematic does not relate to biological structures and typically pertains to methodical approaches or processes.

Understanding the hierarchy of biological organization—cells, tissues, organs, and systems—helps clarify the roles that different structures play in the body.