| Term | Definition |
|---|---|
1) | atom |
2) | molecule |
3) | organelles |
4) | cell |
5) | tissue |
6) | organ |
7) | organ system |
8) | organism |
definition of atom | The smallest unit of an element. Examples: carbon, oxygen, and hydrogen. |
definition of molecule | Two or more atoms chemically bonded together. Example: water (H₂O). |
definition of organelle | A specialized structure inside a cell that performs a specific job. Example: the nucleus or mitochondria. |
definition of cell | The basic unit of life. Example: a muscle cell or nerve cell. |
definition of tissue | A group of similar cells working together to perform a function. Example: muscle tissue. |
definition of organ | A structure made of different tissues working together. Example: the heart. |
definition of organ system | A group of organs working together to perform major body functions. Example: the digestive system. |
definition of organism | An individual living thing made up of one or more cells. Example: a human, dog, or tree. |