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25 Cards in this Set

  • Front
  • Back
hollow ball of cells that gives rise to all the tissues and organs of an adult body
in animals, the outer layer of embryonic tissue from which the skin and nervous system develop
inner layer of embryonic tissue from which the digestive organs develop in animals
middle layer of embryonic tissue in animals from which the skeleton and muscles develop
an animal's shape, symmetry, and internal organization
Body Plan
irregular in shape
arrangement of body parts around a central axis
radial symmetry
arrangement of body parts so there are distinct left and right halves that mirror each other
Bilateral symmetry
in bilaterally symmetric animals, the development of a head end with a concentration of nerves and sensory structures
fluid-filled body cavity that forms between the body wall and the digestive tract
an animal that lacks a coelom, or body cavity
animal with a body cavity located between the endoderm and the mesoderm
animal with a body cavity located entirely within the medsoderm
branching diagram that shows how animals are related through evolution
Phylogenetic tree
a digestive ca vity with only one opening; found in simple animals
Gastrovascular cavity
simultaneous uptake of oxygen and release of carbon dioxide, by the lungs, gills, or through the skin
extremely thin projection of tissue rich in blood vessels that is the site of gas exchange in aquatic and a few terrestrial animals
system in which blood leaves the blood vessels and bathes the body's tissues
Open circulatory system
system in which the blood does not leave the blood vessels and materials diffuse across the walls of the vessels
Closed circulatory system
support structure that consists of water contained under pressure in a closed cavity
Hydrostatic skeleton
hard external covering of some invertebrates
an internal skeleton composed of a hard material, such as bone
organism with both testes and ovaries
union of egg and sperm occuring outside the body or either parent
External fertilization
fertilization that occurs within the body of the femal parent
Internal fertilization