Aquatic- Refers to anything related to water, freshwater most times. Marine- Refers to anything related to sea. Terrestrial- Refers to anything related to land/earth. Culture Medium- Atrificial controlled surface to allow bacteria to grow. Created with proper nutrients for specific bacteria. Nutrient Agar is used. Colony- Identifiable spots on medium represents millions of bacteria. Spores- Reproductive unit of fungi, protozoans, and some other plants. Cyst- In an animal or plant, thin walled, hollow organ cavity or sac. Coelom- Body cavity present in some animals that contains internal organs. Ectoderm- Outermost layer of germ layer, develops into skin, nerves, shells, scales, feathers, fur. Mesoderm- Middle germ layer, develops into muscle and other systems. Endoderm- Inner germ layer, develops into vessels and gut lining. Cephalization- The tendency of important organs to locate in or near the head.