Phylum Porifera
Specialized cells that define the phylum and use flagella to pump water and capture food particles
Choanocytes
The specialized stinging cells that define this phylum
Cnidocytes
Since they have no coelom or other body cavity, flatworms are described by this term
Acoelomate
The animal body plan characteristics.
Symmetry
Segmentation
Body cavities
modularity/coloniality
Constrained and unconstrained body plans
Size and shape
What are the steps of evolutionary development?
Gamete formation, fertilization, cleavage, gastrulation, organogenesis, growth
The major structural protein in sponges that ranges from jelly-like to as hard as a fingernail and helps form the sponge skeleton
Collagen (spongin)
The two primary body plans of Cnidarians
Polyps and medusae
Specialized excretory cells used to filter interstitial fluid
Flame cells
The repetition of structures along the longitudinal axis of an adult body, which results from a series of mesodermic somites formed during development.
Segmentation
In protostomes, what does the blastopore form?
Mouth
The large exit hole in which water is expelled from the sponge
Osculum
The jelly-like and non-cellular layer that acts as structural support
Mesoglea
The part of the body that has hooks and suckers for attachment to the host
Scolex
The evolutionary trend toward the concentration of sensory organs and a mouth at the anterior end of the body.
Cephalization
Why would the earliest stages of development be the most common among all phyla?
Share a common ancestor
Delicate stage, life is fragile and small
Microscopic elements with sponges that help with structure and can be made of glass or limestone
Spicules
In hydrozoans, individual units of a colony are referred to as
Zooids
Mesodermal cells that fill the space between the gut and the ectoderm
Parenchyma
Internal structures that allow for greater separation of function and localization of organs,
Body cavities
What is the archenteron?
The internal cavity that is formed through invagination, in which the opening is a blastopore
The most efficient sponge body plan, characterized by a high internal surface area with many canals and chambers
Leuconoid body
The asexual process in Class Scyphozoa where a polyp forms a series of tiny saucer-like buds called ephyrae
Strobilation
The class that contains free-living species of flatworms
Class Turbellaria
Organisms that grow by adding genetically identical modules. (& what Phyla is this present in?)
Modular organisms (Porifera)
In organogenesis, what do the 3 germ layers form specifically?
Ectoderm: Outer layers (skin, nervous system)
Endoderm: Gut
Mesoderm: Support and movement