Vocabulary:
Symmetry
Bilateral Symmetry: The property of being divisible into symmetrical halves on either side of a unique plane.
Radial Symmetry: Body plane in which body parts repeat around the center of the body.
Direction
Dorsal: The back/top of a body
Ventral: The bottom side of a body
Anterior: Away from the back end of the body and towards the front
Posterior: Away from the front end of the body and towards the back
Bilateral Symmetry: The property of being divisible into symmetrical halves on either side of a unique plane.
Radial Symmetry: Body plane in which body parts repeat around the center of the body.
Direction
Dorsal: The back/top of a body
Ventral: The bottom side of a body
Anterior: Away from the back end of the body and towards the front
Posterior: Away from the front end of the body and towards the back
Tissues
Ectoderm: Outermost germ layer of most animals; gives rise to other layers of skin, sense organs, and nerves.
Mesoderm: The middle germ layer of most animals; Gives rise to muscles and much of the circulatory, reproductive, and excretory systems.
Endoderm: The innermost germ layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the lining of the gut and associated structures.
Ectoderm: Outermost germ layer of most animals; gives rise to other layers of skin, sense organs, and nerves.
Mesoderm: The middle germ layer of most animals; Gives rise to muscles and much of the circulatory, reproductive, and excretory systems.
Endoderm: The innermost germ layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the lining of the gut and associated structures.
Body Cavities
Coelom (uncoelomate): The body cavity in metazoans, located between the intestinal canal and the body wall.
Pseudocoelom: A second body cavity (the first being the gut) which occupies a space between the mesoderm of the body wall and the endoderm of the gut.
Acoelomates: an invertebrate lacking a coelom; especially : one belonging to the group comprising the flatworms and nemerteans (class Nemertea or Nemertinea) and characterized by bilateral symmetry and a digestive cavity that is the only internal cavity.
Coelom (uncoelomate): The body cavity in metazoans, located between the intestinal canal and the body wall.
Pseudocoelom: A second body cavity (the first being the gut) which occupies a space between the mesoderm of the body wall and the endoderm of the gut.
Acoelomates: an invertebrate lacking a coelom; especially : one belonging to the group comprising the flatworms and nemerteans (class Nemertea or Nemertinea) and characterized by bilateral symmetry and a digestive cavity that is the only internal cavity.
Skeletons
Exoskeleton: A skeleton like structure that is on the outside of the body.
Endoskeleton: A skeleton that is on the inside of the body
Exoskeleton: A skeleton like structure that is on the outside of the body.
Endoskeleton: A skeleton that is on the inside of the body
Other:
Cephalization: Evolving to have a head/central nerve/brain
Cephalization: Evolving to have a head/central nerve/brain