Which level of biological organization is a group of similar cells that perform a specific function?

The correct answer is B, tissue. In biological organization, a tissue is defined as a group of similar cells that work together to perform a specific function. For example, muscle tissue is made up of muscle cells that contract to facilitate movement. This level of organization is crucial as it lays the foundation for higher levels, such as organs and systems.

In contrast, an organ is a structure composed of different types of tissues that work together to perform more complex functions, such as the heart or lungs. A community refers to groups of different species living and interacting in the same area, while an ecosystem encompasses the community along with the physical environment, highlighting the interactions between living organisms and their surroundings. Understanding these distinctions clarifies the hierarchy within biological organization, illustrating how tissues serve as building blocks for more complex structures and functions in living organisms.