Which level of biological organization is represented by a group of similar cells working together?

The correct answer is tissue because it refers to a group of similar cells that combine to perform a specific function. In biology, the organization of life is structured in various levels: cells form tissues, tissues form organs, organs form systems, and systems complete an organism. Tissues are specialized for particular tasks; for example, muscle tissue contracts to enable movement, while nervous tissue transmits signals across the body. This concept highlights how cells work collaboratively to fulfill complex roles that are more efficient than individual cells acting alone. Understanding tissues is fundamental to studying how organs and systems function, as each tissue type contributes to the overall health and operation of the body.