Answer:
Tissue
Step-by-step explanation:
The levels of organization go as follows:
Atom - the building blocks of all living and nonliving material
Molecule - two or more atoms that join together in chemical bond
Organelle - two or more molecules working together to perform a particular function in a cell
Cell - the smallest unit that exhibits all of the characteristics of life
Tissue - two or more cells that work together to perform a particular function
Organ - two or more tissues that work together to perform a particular function
Organ System - two or more organs that work together to perform a particular function
Multi-Celled Organism - two or more organ systems that work together