1. Organism: This is the most basic level, consisting of a single living thing. Examples include a single tree, a bird, or a bacterium.

2. Population: A group of individuals of the same species living in the same area at the same time. Examples include a flock of birds, a herd of deer, or all the oak trees in a forest.

3. Community: All the different populations of organisms living and interacting in a particular area. Examples include a forest community, a coral reef community, or a pond community.

4. Ecosystem: A community of organisms and their physical environment, including all the living and non-living factors. Examples include a desert ecosystem, a rainforest ecosystem, or a freshwater lake ecosystem.

Biosphere itself encompasses all the ecosystems on Earth, making it the highest level of organization in the biological world.