| A | B |
|---|
| Abiotic | A term that describes a nonliving factor in an ecosystem. |
| Active transport | The movement of particles from an area of low concentration to an area of high concentration that uses energy provided by ATP or a difference in electrical charges across a cell membrane. |
| ATP | Adenosine Triphosphate |
| Adenosine triphosphate | A molecule that provides energy for cell reactions and processes. ATP releases energy when one of its high-energy bonds is broken to release a phosphate group. |
| Adhesion | The intermolecular attraction between unlike molecules. Capillary action results from the adhesive properties of water and the molecules that make up plant cells. |
| Agriculture | The artificial cultivation of food, fiber, and other goods by the systematic growing and harvesting of various organisms. |
| Allele | A variation of a gene's nucleotide sequence (an alternative form of a gene). |
| Allele frequency | The measure of the relative frequency of an allele at a genetic locus in a population; expressed as a proportion or percentage. |
| Analogous Structure | A physical structure, present in multiple species, that is similar in function but different in form and inheritance. |
| Aquatic | A term that describes an organism associated with a water environment. |
| Atom | The smallest unit of an element that retains the chemical and physical properties of that element. |
| Biochemical Conversion | The changing of organic matter into other chemical forms such as fuel. |
| Bioenergetics | The study of energy flow (energy transformations) into and within living systems. |
| Biogeochemical Cycles | The movement of abiotic factors between the living and nonliving components within ecosystems; also known as nutrient cycles. |
| Biological Macromolecules | A group of biomacromolecules that interact with biological systems and their environments. |
| Biology | The study of life. |
| Biome | A large area or geographical region with distinct plant and animal groups adapted to that environment. |
| Biosphere | The zone of life on Earth; sum total of all ecosystems on Earth. |
| Biotechnology | Any procedure of methodology that uses biological systems or living organisms to develop or modify either products or processes for specific use. This term is commonly associated with genetic engineering, which is one of many applications. |
| Biotic | A term that describes a living or once-living organism in an ecosystem. |
