Environment
The sum of all external conditions and influences that affect the development and, ultimately, the survival of an organism or group of organisms.

Food chain
The transfer of food energy from organisms in one nutritional level to those in another.

Food web
The complex and interlocking series of food chains.

Fungi
Small, often microscopic, organisms that lack chlorophyll and cellulose in their cell walls. Fungi are important decomposers of organic wastes.

Growth ring
A layer of wood formed in tree or other woody plant during one growth period.

Adaptation
The process of adjusting to the environment over time. For example a plant with unusually long roots, enabling it to absorb water over a wide area, may be more likely to survive during periods of drought.

Growth rings
Layers of wood formed in tree or other woody plant during one growth period.

Adapted
Suited to certain conditions in the environment.

Habitat
An area that provides an animal or plant with adequate food, water, shelter, and living space in a suitable arrangement.

Aquatic
Living or growing in water.