Answer:
population
Step-by-step explanation:
These are the levels of ecological organization ( from smallest to largest): organisms, populations communities, ecosystem, and biopshere.
Organisms: This level is a single organism from a species.
Population: This level is all the organisms of the same species that love in the same area at the same time
Community: This level is all the populations of different species that live in a certain area.
Ecosystem: This level is the community and all the abiotic factors that influence that community
Biosphere: This is level is Earth.