Chapter 28 Flashcards
What is the Colonial flagellate hypothesis?
That a collection of flagellated cells may have formed to cause multi cellular animals to be formed. (Choanoflagellates)
Bilateral Symmetry
Definite right and left halvs
Asymmetry
No particular body shape
Radial Symetry
Two identical halves
Protostomes
First embryonic opening becomes the mouth; Spiral Cleavage
Deuterosomes
Second embryonic opening becomes the mouth Radial Cleavage
Cleavage
Cell division without cell growth
What are some major features of animals ?
See colonial flagellate hypothesis. Also, animals are heterotrophic, sexual (asexual in odd cases), multi cellular, and digest food internally. Also vertebrate (backbone) vs invertebrate (no backbone).
What are some basic sponge features and characteristics?
They reproduce asexually by fragmentation/budding, and are the only level of animal to lack a true tissue. They are also able to regenerate their tissue.
What makes Cnidarians Cnidarians?
They all have Cnidocytes (little stingery tentacles). They are usually tubular. (They are part of Hydra [supergroup not evil organization]).
What are the four (or 3 not sure) groups of Cnidarians?
Hydra: Tiny Jellyfish
True Jellies: Actual Jellyfish
Coral: Hard-Bodied, Sessile
Anenomes: Sessile Polyps
What makes a lophotrochozoan what it is?
It is bilaterally symmetrical. The embryos have three germ layers. Protosmoic pattern of development. Adults have organ levels of orginizations.
Some have true ceolms.
What are the two groups of lophotrochozoan?
- Lophophorans (bryozoans, brachiopods, phoronids)
- Trochozoans (flatworms, rotifers, molluscs, annelids)
Mollusk
Have a visceral mass: Contains internal organs
Mantle: May secrete shell or contribute to development of gills or lungs
Foot: Muscle adapted for locomotion, attachment, or food capture
Reduced celom.
Two major groups of Mollusk?
Bivalves- Think clams and oysters
Cephalapods - Think squids
Gastropods- Think slugs and snails
