A part of an organism consisting of an aggregate of cells having a similar structure and function is called what?

• A. Toxicology
• B. Trajectory
• C. Tissue
• D. Trauma

Answer: (C)

Grouping cells by similar structure and function forms tissue, a basic level of organization in living organisms. This arrangement lets the cell group work together on a shared task, such as muscle tissue contracting to move, nervous tissue transmitting signals, or epithelial tissue protecting surfaces. The other ideas refer to different concepts: toxicology studies poisons, trajectory is the path of a moving object, and trauma means injury. So the part of an organism made up of a coordinated group of similar cells is tissue.