Ans: In ecology, the levels of organization range from organism to biosphere.
Organism .
An organism is defined as an individual animal, plant, or single celled life form. An organism may be unicellular or multicellular.
Population
A group of the organisms of the same species inhabiting a specific geographical area (habitat) at a particular time is called a population. ,
Community
All the populations that live in a habitat and interact in various ways with one another are collectively called a community.
Ecosystem
The self-sufficient unit of an environment that is formed as a result of interactions between its biotic community and the abiotic components is known as an ecosystem.
Example: A pond, a lake, and a forest are examples of natural ecosystems. Ecosystems may also be artificial for example an aquarium.
Biosphere
All ecosystems of the world together form the biosphere. It includes all the ecosystems of the planet Earth. In other words, the biosphere consists of all organisms present on the Earth and all regions of the Earth where they live. Biosphere ranges from the floor of oceans to the tops of the highest mountains. It is about 20 kilometres thick.
The biosphere makes a thin layer surrounding the planet Earth, If you consider the Earth as of the size of an apple, then the biosphere will be as thick as the apple's skin. .