Question

Can you define population, community, ecosystem, and biosphere? How are they each related to each other?

Answer 1

These are all organizational units used in ecology.

Explanation:

These are all organizational units used in ecology.

I would typically mark this as a duplicate, but because the answer to your question has been explained well through multiple answers across the site, I am going to point you to the following answers for more information:

Population
Community
Ecosystem
Biosphere

What is the difference between a population, a community, and an ecosystem?
How does an ecosystem differ from a biosphere?