The shape , the physical characteristics, or appearance of an object or thing.

Job, purpose or responsibility that a person or thing performs.

A group of similar cells that work together to perform a specific function

A collection of tissues that perform a common function

A group of organs working together to perform a certain task.

Anything outside the body of an organism that can cause a response

A change from within an organism such as hunger or thirst that cause an organism to respond.

A group of parts that work together as a whole

Any living thing