* The Biosphere: The biosphere is the part of Earth that supports life. It includes all living organisms, their habitats, and the interactions between them.

* Trees as Living Organisms: Trees are living organisms, made up of cells, capable of growth, reproduction, and interacting with their environment.

* Trees as Part of Ecosystems: Trees are vital components of many ecosystems, like forests, woodlands, and even some grasslands. They provide food and shelter for animals, contribute to oxygen production, and play a key role in carbon cycling.

Therefore, a tree is a clear example of a living organism that exists within the biosphere and plays an important role in its functioning.