Question | Answer |
invertebrate | An animal that lacks a backbone. |
filter feeder | An organism that obtains food from water circulating through the its body. |
radial symmetry | A body pattern in which several different planes could divide an animal into equal halves. |
nematocyst | A stinging cell used by cnidarians for defense or for capturing food. |
bilateral symmetry | A type of symmetry in which there are two equal sides to an animal; only one plane can divide it into equal halves. |
ganglion | A mass of nerve tissue;sometimes called a simple brain. |
stimulus | Anything that causes a response in an organism. |
closed circulatory system | A type of circulation in which the blood remains in vessels. |
aortic arches | Organs that help to control blood pressure in earthworms. |
water-vascular system | A series of canals and tubules in echinoderms; used for movement and feeding. |
exoskeleton | An external skeleton composed of tough plates that protect and support certain animals. |
compound eye | An eye having many small lenses that provides a mosaic of images rather than a single image |
open circulatory system | The type of circulation in which the blood passes from blood vessels into body spaces around organs and tissues before returning to the heart. |
tracheae | One of the tiny tubes that branch throughout the body, carrying air to the tissues; in humans and vertebrate animals, the tube that carries air between the pharynx and the lungs |
metamorphosis | A changing of an animal's shape or form as the animal develops from an egg to an adult. |
molting | To shed scales, feathers, fur or an exoskeleton |
incomplete metamorphosis | Insect metamorphosis that includes three stages: egg, nymph, and adult. |
nymph | The immature stage of an insect with incomplete metamorphosis. |
complete metamorphosis | Insect metamorphosis that consists of four stages: eggs, larva, pupa, and adult. |
larva | An immature stage in the life cycle of many animals. |
pupa | A resting stage during the complete metamorphosis of certain insects. |