Chapters 28-32 Flashcards
(39 cards)
Irregular in shape.
Asymmetrical.
Arrangement of body parts so there are distinct left and right halves that mirror each other.
Bilateral symmetry.
Hollow ball of cells that gives rise to all the tissues and organs of an adult body.
Blastula.
An animal’s shape, symmetry, and internal organization.
Body plan.
In bilaterally symmetric animals, the development of a head end with a concentration of nerves and sensory structures.
Cephalization.
In animals, the outer layer of embryonic tissue from which the skin and nervous system develop.
Ectoderm.
Inner layer of embryonic tissue from which the digestive organs develop in animals.
Endoderm.
An internal skeleton composed of a hard material, such as bone.
Endoskeleton.
A hard external covering of some invertebrates.
Exoskeleton.
Middle layer of embryonic tissue in animals from which the skeleton and muscles develop.
Mesoderm.
Arrangement of body parts around a central axis.
Radial symmetry.
Parasitic flatworm of the class Trematoda.
Fluke.
Free-swimming, jelly-like, often umbrella-shaped body form of a cnidarian; jellyfish.
Medusa.
Barbed harpoon within a cnidocyte of a cnidarian; used to spear prey.
Nematocyst.
Cylindrical, pipe-shaped body form of a cnidarian, usually attached to a rock or other object.
Polyp.
Describes an organism that remains attached to a surface for its entire lifetime.
Sessile.
Needles of silica or calcium carbonate in the skeleton of some sponges.
Spicules.
The primitive brain contained in one anterior segment of an annelid.
Cerebral ganglion.
In a mollusk, muscular region used for locomotion.
Foot.
Heavy fold of tissue that surrounds the visceral mass of mollusks.
Mantle.
Rasping tongue-like organ of mollusks used in obtaining food.
Radula.
External bristles of annelids.
Setae.
Central section of a mollusk’s body that contains its organs.
Visceral mass.
In arthropods, a structure that extends from the body wall.
Appendages.
