The levels of ecological organization from smallest to largest are; Organism, population, community, ecosystem
The seven major levels of ecological organization from the smallest to the largest are; organisms, population, biological community, ecosystem, landscape, biome and biosphere.
Organisms are discrete and complete living things such as animal, plant, fungus or microorganism that performs all life processes independently. Organisms are fully adapted to their environments and those that belong to a closely related group (genus) are capable of interbreeding to produce fertile offspring.
A population is a collection of organisms of a particular species that inhabit the same area and interact with one another.