(a kyə rət): (1) Free from error especially as the result of care; (2) conforming exactly to truth or to a standard.

(al jē): Simple, plantlike organism.

(kar bun): A chemical element present in all life forms.

(klī mǝt): The average weather conditions of a particular place or region over a period of years.

(i kä lǝ jist): A scientist who studies the relationship between living things and their environment.

(ē kō sis tǝm): A system made up of an ecological community of living things interacting with their environment especially under natural conditions.

(ik stiŋ(k)t or ek stiŋ(k)t): No longer existing.

(fresh wȯ tǝr): (adjective) living in or taken from fresh water; (noun) water that is not salty.

(fun jī): Organisms without chlorophyll that reproduce by spores. Mushrooms, molds, mildews, and toadstools are examples.

(ha bә tat): The place or environment where a plant or animal naturally or normally lives and grows.

(mär sü pē əl): Any of an order of mammals (such as kangaroos and opossums) that have a pouch on the abdomen of the female containing the teats and serving to carry the young.

(äb sәr vā shәn): An act of recognizing and noting a fact or occurrence often involving measurement with instruments.

(ri lī ə bəl): Dependable.

(vərt ə brət or vərt ə brāt): Any of a large group of animals (such as mammals, birds, reptiles, amphibians, and fishes) that typically have a bony or cartilaginous backbone which replaces the notochord, a distinct head containing a brain which arises as an enlarged part of the nerve cord, and an internal usually bony skeleton and including some primitive forms (such as lampreys) in which the backbone is absent and the notochord persists throughout life.