| adaptation | A structure or behavior that helps a plant or animal live in its surroundings. |
| algae | A marine or freshwater plant or plant-like organism that usually contains chlorophyll. |
| analyze | To study or determine the nature and relationship of the parts, suggest separating or breaking down the parts of something to understand its true nature. |
| annuals | Plants that complete their life cycles in one growing season. |
| arid | Lacking in rainfall, very dry. |
| atmosphere | The layer of gases, like air, that surrounds the Earth. |
| basin | A low, bowl-shaped area of land surrounded by higher lands. |
| biome | A community of plants and animals living together in a particular climate. |
| broadleaf | A type of tree with wide, flat leaves. |
| carbon dioxide | A gas in air that is taken in by plants, exhaled by animals, and given off when fuel is burned. A carbon dioxide molecule is formed when two oxygen atoms combine with a single carbon atom. |
| Celsius scale (C) | The metric temperature scale where 0 degrees is assigned to the temperature where water freezes, and 100 to the temperature where water boils. |
| centimeter (cm) | A unit of length in the metric system. There are 100 centimeters in a meter. |
| chlorophyll | A green pigment found in plants, necessary for conducting photosynthesis. |
| classify | To arrange in groups according to specified similarities. |
| climate | The average weather conditions of an area over many years, as measured by temperature, wind speed, and precipitation. |
| community | The whole group of plants and animals that interact in a common location. |
| competition | The active demand by two or more organisms, such as plants, for some environmental resource in short supply. |
| conserve | To preserve, or to avoid wasteful use. |
| correlate | To show a relationship between things. |
| deciduous tree | One of a group of trees that lose their leaves in the fall. |
| dormant | Inactive or asleep, but capable of waking up; not actively growing, but protected from the environment. |
| drought | A period of dryness, that when prolonged, causes damage to crops; a shortage of water. |
| elevation | The height of a place above sea level. |
| environment | The surroundings in which a person, plant or animal lives, including the air, water, and land. |
| epiphyte | An organism that grows on another organism. The two organisms do not take nutrients from or give nutrients to each other. |
| equator | An imaginary circle around the Earth that lies halfway between the North Pole and the South Pole. |
| evaporate | To change from a liquid to a gas. |
| evergreen | A plant that stays green all year, including firs and pines. |
| fluctuate | To change back and forth uncertainly. |
| fungus | An organism that grows from spores, not seeds, usually classified as a plant without chlorophyll, such as mold, mildew, mushrooms, and yeast. |
| growing season | The time of the year when crops grow. |
| humid | Containing moisture. |
| hypothesis | An educated guess; a likely explanation for a problem. |
| insulate | To separate to prevent transfer of electricity, heat, or sound. |
| investigate | To observe or study closely. |
| landforms | Shapes, like mountains or hills, that make up the Earth's surface. |
| latitude | Imaginary lines on a map or globe that measure distance in degrees north or south of the equator. Latitude lines extend horizontally, from east to west on a globe. |
| longitude | Imaginary lines on a map or globe that measure distance in degrees east or west of the prime meridian. Longitude lines extend vertically, from pole to pole on a globe. |
| mean | The average. |
| millimeter (mm) | A unit for measuring length in the metric system. There are 10 mm in 1 cm, and 1,000 mm in a meter. |
| needleleaf | A type of tree with long, thin leaves. |
| nutrient | A material that plants and animals need to live and grow. |
| organism | A living being. |
| oxygen | A gas that is given off by plants and used by animals. |
| perennials | Plants that complete a growing cycle each year for several years. |
| photosynthesis | The process by which plants use light, carbon dioxide, and water to make food. |
| plain | A large area of flat or nearly flat land. |
| prairie | Flat land covered with tall grass and wildflowers. |
| precipitation | Moisture that falls to the ground from clouds; includes rain, snow, sleet, and hail. |
| predominant | Most frequent or most common. |
| property | Something about an organism or object that can be observed, such as size or shape; characteristics common to all members of a group. |
| reflect | To bend or fold back, to change direction. |
| region | A large area with common features that set it apart from other areas. |
| resource | Something that is useful. |
| sod | A thick layer of soil. |
| species | A group of organisms having common attributes and given a common name. |
| steppe | A flat, dry plain covered with short grass. |
| symbiosis | Living together in a way that benefits both individuals. |
| temperature | The degree of hotness or coldness of a substance as measured by a thermometer. |
| thrive | To flourish or grow vigorously. |
| tolerate | To put up with, endure, or withstand. |
| vegetation | Plant life of an area. |
