What does tissue refer to in biological terms?

In biological terms, tissue is defined as a collection of similar cells that perform a specific function. This definition is foundational to understanding how multicellular organisms are structured and function. Tissues are central to the organization of cells into functional units, which then contribute to the overall workings of organs and systems within an organism.

For example, in animals, there are various types of tissues such as muscle tissue, nerve tissue, and epithelial tissue, each specialized for particular roles that are essential for survival and growth. The collaboration of these different tissues allows for the complexity and efficiency seen in organisms.

The other options do not accurately represent the concept of tissue. While an organ is composed of multiple types of tissues working together, it is more complex than just tissue itself. A group of organelles refers specifically to the structures within a cell, which is a level of organization distinct from tissue. Lastly, the basic units of matter pertain to atoms and molecules rather than biological structures, making them irrelevant in the context of defining tissue.