(al pīn): Of, relating to, or growing on mountain slopes above the highest elevation where trees grow.

(an(t) thə sī ə nən): Any of various soluble pigments producing blue to red coloring in flowers and plants.

(ärk tik): Of, relating to, or suitable for use at the north pole or the region around it.

(klȯr ǝ fil): The green coloring matter that is found chiefly in the chloroplasts of plants and is necessary for photosynthesis.

(krī tir ē ə): (singular: criterion) A standard on which a judgment or decision may be based.

(di si jǝ wǝs): Having parts, like leaves, that fall off or shed seasonally or at a certain stage of development in the life cycle.

(i kwā zhǝn): A statement of the equality of two mathematical expressions.

(i val yə wāt): To decide the value or worth of after study.

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

(hī pä thǝ sǝs): An assumption or idea that is proposed for the sake of argument so that it can be tested to see if it might be true.

(in(t) sə lāt): To separate from conducting bodies by means of nonconductors so as to prevent transfer of electricity, heat, or sound.

(lēf li tər): Dead plant material, like leaves and twigs.

(mī krōb): An organism (such as a bacterium) of microscopic or less than microscopic size; a germ.

(mī grǝ tȯr ē): Of, relating to, or characterized by moving, usually periodically, from one region or climate to another for feeding or breeding.

(nī trə jən): A colorless tasteless odorless element that occurs as a gas which makes up 78 percent of the atmosphere and that forms a part of all living tissues.

(nü trē ǝnt): A substance or ingredient that promotes growth, provides energy, and maintains life.

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

(ȯr gǝ ni zǝm): An individual living thing that carries on the activities of life by means of organs which have separate functions but are dependent on each other: a living person, plant, or animal.

(ō zōn): A form of oxygen that is a bluish, irritating, sharp-smelling gas containing three atoms per molecule, and that is used especially in disinfecting, deodorizing, and bleaching.

(pä lə sē): A course of action chosen in order to guide people in making decisions.

(smäg): A thick haze caused by the action of sunlight on air polluted especially by smoke and automobile exhaust fumes.

(trō pǝ sfir): The portion of the atmosphere which extends from the Earth’s surface to the bottom of the stratosphere (a distance of about 7 miles or 11 kilometers) and in which temperature generally decreases rapidly with altitude.

(ǝr bǝn): Of, relating to, typical of, or being a city.

(wȯ tǝr shed): A region or area bounded on the edge by a dividing ridge and draining ultimately to a particular watercourse or body of water.