The phyla where all the animals belong to except sponges; have differentiated cells and true tissues derived from germ layers
Eumetazoa
Have two germ layers: endoderm and ectoderm
Diploblastic
The outer most primary germ layer of an animal embryo, it gives rise to the outer covering of the animal, such as skin and the accessory organs associated with skin
Ectoderm
The innermost primary germ layer, which gives a rise to the cells that line the digestive tract and its accessory organs (liver, pancreas) and the cell that line the respiratory tract in the lungs in higher animals
Endoderm
The major diploblastic phylum
Cnidaria
Possess a mesoderm germ layer in addition to ectoderm and endoderm
Triploblastic
Lies between the ectoderm and endoderm; Gives a rise to cells between the integument and digestive tract, internal body cavity (coelom)
Mesoderm
A space or cavity between the digestive tract snd outer body; the space is completely lined with mesoderm-derived tissue
Coelom
The body type that the Phylum Cnidarians have
Diploblastic Acoelomates
Do not possess a colem, although they have mesoderm. The region between the digestive tract and outer body wall is filled with mesodermal-derived cells
Triploblastic Acoelomate
This phylum have a triploblastic acoelomate body type
Platyhelminthes
Possess an internal fluid-filled body cavity, but the cavity is incompletely lined with mesoderm-serviced tissues
Pseudocoelomate
Fluid-filled cavity completely lined with mesodermal-derived cells
Coelomates
The several organ system systems are suspended within the coelom by double layers of mesodermal-derived tissues called
Mesenteries
Why have a body cavity?
1) Room for organs to grow and develop
2) Increased surface area
3) Hydrostatic skeleton used for support
4) Store material
5) A route to pass nitrogenous wastes and gametes to the outside
Symmetrical animal that can be divided by many planes through the central axis of its bod running from the top to the bottom
Radially
Symmetry that there is no central axis that can be divided into equal halves
Asymmetrical
May be divided into two mirror halves only through one longitudinal plane
Bilaterally symmetrical
Divides the body into superior and inferior parts
Transverse Plane
Divides the the body into a front and back parts
Frontal plane
Divides the body into left and right parts
Sagittal plane
An evolutionary trend towards concentrating sensory and nervous systems at the anterior end of the organism
Cephalization
1) Cellular level of organization
2) Somatic regeneration
3) Totipotent
4) No germ, digestive tracts, or coeloms
5) Water moves through pores, canals and cavities
6) Choanocytes
7) Composed of many spicules
8) Do not show cephalization or segmentation
9)
Porifera
Each cell can potentially give rise to any other cell type
Totipotent
They hace spicules of calcium carbonate and all are marine
Class Calcarea
The glass sponges have spicules of glass and are found mostly in deep-water marine environments
Class Hexactinellida
The "bath sponge"; glass spicules and or spongin fibers in their skeleton
Class Demospongiae
1) Diploblastic, acoelomate
2) Two dermal layers: epidermis, inner gastrodermis
3) Unsegmented
4) Two distinct body forms: Polyp and medusa
5) No specialized integument
6) Digestion occurs extracellular in the gastrovascular cavity
7) No specialized repos
Cnidaria
An acellular gelatinous layer between the two dermal layers
Mesoglea
They produce multiple medusae off of one polyp
Strobilization
Usually have the polyp as the only form
The polyp is a radial symmetrical, cylinderal animal with a mouth surrounded by a ring of tentacles
Hydrozoans
The medusa is often the dominant life cycle stage, the polyp primarily serves a means to produce medusae. The medusae are bell or umbrella-shaped animals with their mouths pointing downwards
Scyphozoa
Do not have a medusa stage
Anthozoans
Some colonial cnidarians have an protective outer covering
Perisarc
The cnidarian epidermis contains stinging cells
Cnidocytes
Cnidocytes posses a spiked, harpoon-like organelle
Nematocyst