This is an encyclopedia entry for "biosphere." The biosphere is made up of the parts of Earth where life exists. The biosphere extends from the deepest root systems of trees, to the dark environment of ocean trenches, to lush rain forests and high mountaintops. Text for this entry is appropriate for the middle and high school grade levels.

This encyclopedia entry is for the term "food chain." A food chain describes who eats whom in the wild. Text for this entry is appropriate for the upper elementary, middle and high school grade levels.

This is an encyclopedia entry for the term "herbivore." An herbivore is an organism that mostly feeds on plants. Text for this entry is appropriate for the upper elementary, middle, and high school grade levels.

This is an encyclopedia entry for the term "omnivore." An omnivore is an organism that regularly consumes a variety of material, including plants, animals, algae, and fungi. Text for this entry is appropriate for upper elementary, middle, and high school grade levels.