Nature
everything in the universe except what humans have manufactured
Atoms
Fundamental building blocks of life
Molecules
Units in which atoms are joined together
Cell
Smallest unit of life that can survive and reproduce on its own
Organism
Individual that consists of one or more cells
Population
Each population is a group of individuals in a specific area
Community
Consists of all the populations in a specific area
Ecosystem
Community interacting with its physical and chemical environment
Bioshpere
Most inclusive level, encompasses all regions of Earth
Energy
The capacity to do work
Nutrient
Particular type of atom or molecule that has an essential role in growl and survival