Zoology Flashcards
Body Plan
the general structure each individual organism assumes as it develops.
Symmetry
correspondence of body parts, in size, shape, and relative position, on opposite sides.
Cephalization
differentiation of the anterior (front) end of an organism into a definite head.
Coelom
the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs
Asymmetry
the absence of or deviation from the regular disposition of similar parts of the body relative to a specific point.
Radial Symmetry
symmetry about a central axis
Bilateral Symmetry
the property of being divisible into symmetrical halves on either side of a unique plane.
Germ Layers
a group of cells in an embryo that interact with each other as the embryo develops.
Endoderm
an embryonic germ layer that gives rise to tissues that form internal structures and organs.
Mesoderm
a germ layer that arises during gastrulation, and is present between the ectoderm.
Diploblastic
an animal with a body wall composed only of two layers.
Triploblastic
organisms whose body is derived from three embryonic cell layers
Acoelomate
an invertebrate lacking a coelom
Pseudocoelomate
a fluid filled body cavity.
Through gut
Complete digestive system
