cells

The cell is the basic unit of structure and function of a living thing.

and there are more then one cell in and human body and cells work together.

Cells are specialized by size and shape for the job they do

Examples: The amoeba above is made of only one cell and it must perform all the jobs of the organism.

picture is under tissue

tissue
Tissues are made of a group of similar cells that work together to do a specific job in the body.

cell

tissue

organs

Tissues are made of a group of similar cells that work together to do a specific job in the body.

organ system

An organ system is a group of organs working together to perform particular jobs.

oraganism

Sum of all cells, tissues, organs and organ systems makes an organism. An organisms is made when a group of organ systems work together.