1. postanal tail - muscular structure at the end of a developing chordate (animals having at some stage of development a notochord, gill slits, and a dorsal tubular nerve cord).
2. sessile - describes an organism that remains attached to one place during its lifetime.
3. radula - in gastropods, (mollusks having one-piece, straight or spiral shells, as snails) the tonguelike organ with rows of teeth used to scrape and tear food.
4. preening - process in which a bird rubs oil from an oil gland over its feathers to condition them and make them water repellent.
5. mycorrhizae - network of hyphae (a thread-like structure composed of cells attached end to end that forms the main tissue in many fungus) and plant roots that helps plants absorb water and minerals from soil.
