Biology Lessons Part 2: Population Biology

Lesson 2.1: Glossary: How Do Green Plants Grow?


community - groups of organisms of two or more different species living together within the same geographical area where they are likely to interact with each other. Every community of living things depends upon its producers to convert inorganic carbon (from the carbon dioxide in the air) into organic molecules (such as sugar) through the process of photosynthesis.

cotyledon - part of seed surrounding the embryo, the cotyledon serves as a source of nutrients for the germinating plant. The number of cotyledons in the seed serves as a basis for classifying angiosperms into monocotyledons, with one cotyledon, and dicotyledons, with two.

germinate (germinating) - when a seed begins to grow or develop or sprout, generally stimulated by the presence of water at suitable temperatures.

inorganic - describes chemical compounds which do not contain both carbon and hydrogen (hydrocarbon groups); chemical compounds that lack the organized physical structure characteristic of living things; for example, water and minerals are inorganic substances.

organic - describes chemical compounds which contain both carbon and hydrogen (hydrocarbon groups) are usually considered organic; organic compounds form the chemical basis of living things. The major categories of organic compounds found in living things are carbohydrates, lipids, proteins and nucleic acids.

photosynthesis - process by which plants and other producers capture the light energy of the sun and transform it into chemical energy. Producers use light energy to convert inorganic carbon dioxide from the air and water into the sugar glucose, an organic molecule. The glucose is used as an energy source and also as a major building block for the structure of the plant, since sugars are combined to form cellulose. Oxygen is a byproduct of photosynthesis and is released into the air. Photosynthesis also produces an energy transfer molecule called ATP that supports many synthetic reactions in the plant. Since consumers rely on food provided by photosynthesis to sustain them, this process is one of the primary processes supporting life. It also produces most of the oxygen in the air.

producers - any of various organisms, such as green plants and certain algae, which obtain food by producing organic compounds from inorganic carbon dioxide by means of photosynthesis. Producers are a direct or indirect source of food for other organisms. Also called "autotrophs".

seed - a mature and fertilized egg which can germinate and grow into a plant similar to that from which it came.

seedling - a young plant grown from a seed

terrestrial - living or growing on land, not in air or water.