ch 7,8,9 Zoology

Coelom

Coelom

Fluid filled body cavity that contains internal organs

Acoelomate

Invertabrate lacking a coelom

Pseudocoleom

Body cavity that lies between mesoderm and endoderm layer of gut

Triploblastic

Having a body derived from three embryonic cell layers

Diploblastic

Having a body derived from two embryonic cell layers

Endoderm

Innermost of the three primary germ layers of an embryo

Ectoderm

Outermost layer of cells

Mesoderm

Middle of three primary germ layers

Blastula

Embryo development when it is a hollow ball of cells

Gastrula

Following blastula when it is a hollow structure with three layers of cells

Blastopore

region where cells will form the endoderm and mesoderm layers

Monoescious

Having both male and female reproductive organs in the same individual

Diecious

Having male reproductive organs in one individual and female organs in another

Hermaphrodites

Having both male and female reproductive parts in same organism

Parthenogenesis

Reproduction from an ovum without fertilization

Budding

New organism develops from an outgrowth or bud

Oviparous

Producing young by means of eggs that are hatched after they have been laid

Ovoviviparous

Producing young by means of egg that are hatched within the body

Viviparous

Birthing live young that have developed inside the body of the parent

Amnion

Thin membrane with fluids where the embryo is immersed

Allantois

Extra embryonic membrane arising as a pouch or sac

Chorion

Outer membrane that surrounds the embryo

Spherical symmetry

Body shaped like a sphere and all parts radiate equally around center

Bilateral symmetry

Right and left sides are mirrored

Radial symmetry

Similar parts are arranged in a balanced way around the center of the body

Cephalization

Concentration of sense organs, nervous control at the anterior end of body forming a head and brain

Anterior

Nearer the front, especially situated in the front of the body or nearer the head

Posterior

Further back, nearer the rear or hind end

Ventral

Relating to the underside of an animal or plant

Dorsal

Relating to the upperside of an animal or plant

Medial

Situated near the median plane of the body

Lateral

Toward or from the sides or side

Protosome

Multicellular organism whos mouth develops from a primary embryonic opening

Deuterostome

Anus forming before the mouth