Biology Terms +

Process by which some soil bacteria and fungi break down nitrogenous wastes and organic remains; part of a nitrogen cycle.

The smallest unit of an element, a fundamental substance, that still retains the properties of that element.

All sediments and rocky formations of the ocean bottom.

Slow movement of an element from the environment, through food webs, then back to the environment.

One of six vast land areas, each with distinctive kinds and numbers of plants and animals.

Behavior which helps other members of a species but which diminishes an individual's own chance of reproductive success.

The internal time-measuring mechanism which helps adjust an organism's daily activities, seasonal activities, or both, in response to environmental cues.

All of those regions of earth's waters, crust, and atmosphere in which organisms can exist.

Habitually walking upright on two feet; such as, as birds and hominids.

The smallest unit having the capacity to live and to reproduce, independently or as part of a multicelled organism.

The populations of all species occupying the same area; such as, the African savanna's bacteria, grasses, trees, zebras, lions, etc.

1. A group of organisms and the environment in which they interact.
2. A community and its physical environment.

Two or more atoms chemically combined.

A water molecule consists of two atoms of hydrogen and one atom of oxygen.

An individual organism composed of specialized, interdependent cells most often organized in tissues, organs, and organ systems.

1. A structural unit in which a number of tissues, combined in specific amounts and patterns, perform a common task.
2. A relatively independent part of the body that carries out one or more special functions.

The organs of the human body include such areas as the eye, the ear, the heart, the lungs, and the liver.