Lecture 4 Flashcards
in what type of animals do body cavities exist?
-triploblastic animals
what are the 3 grades of body cavities?
-(eu)coelomates
-pseudocoelomates
-acoelomates
what is a (eu)coelomates body cavity?
-full cavity completely lined with mesoderm
-closed circulatory system
what phylums have a (eu)coelomate body cavity?
-annelids
-chordates
-echinoderms
-molluscs
-arthropods
what is a pseudocoelomate body cavity?
-false cavity only partially lined by tissue derived from the mesoderm
what phylum has a pseudocoelomate body cavity?
-nematodes
what is a acoelomate body cavity?
-no body cavity (not completely formed)
-no space between tissue layers
what phylum has a acoelomate body cavity?
-platyhelminthes
what does the lophotrochozoa clade feature?
-animals with a wide range of body forms
-contains bilaterian animals
-have a lophophore
-have a trochophore larva form
what is a lophophore?
-feeding structure in aquatic organisms
what is a trophophore larva form?
-common larval form
-simple
-3 tissue systems
-complete gut (coelomate)
what bilaterian animals are found within the lophotrochozoa clade?
-coelomates (full cavity with a digestive tract and 2 openings)
-ex: annelids, molluscs, brachiopods, rotifers, and flatworms
what are the 4 common structures within the mollusca phylum?
-muscular foot
-mantle
-radula
-visceral mass
what is the purpose of the muscular foot?
-helps with movement, digging, and capturing prey
what is the mantle and what is its purpose?
-water filled chamber containing gills (or lungs), anus, and excretory pores
-produces the shell
what is the purpose of the radula?
-functions as a tongue to capture food
what is the purpose of the visceral mass? why is it pushed in?
-houses internal organs
-pushed in b/c of the large foot
what are the 4 major classes of molluscs?
-gastropods
-bivalvia
-polyplacophora
-cephalopoda
what are the key features of the gastropod class? what are examples?
-1 piece shell
-use radula to feed off plants + algae
-ex: snails + slugs
what are the key features of the bivalvia class? what are examples?
-2 piece shell
-no distinct head
-suspension feeders
-sedentary lives
-ex: clams, oysters, and other bivalves
what are the key features of the polyplacophora class? what are examples?
-many piece shell
-scrape algae from rocks
-ex: chitons