EEMB: Animals - Chordates Flashcards
The acorn worms are under what phylum?
hemichordata
Marine deuterostomes are what?
acorn worms
What body structure was a important development in the metazoans? where is it located?
the pharynx- region posterior to the mouth
Acorn worms use the pharynx as a _____ structure
respiratory
3 principle chordate clades
cephalochordata (lancelets)Urochordata (tunicates)Verbrata (vertebrates)
Members of the chordates have ____ diversity
extreme
The ____ reflects the common ancestry of chordates
notochord
Three shared traits of organisms in phylum chordata
dorsal hollow nerve cordnotochordpost anal tail
What is the notochord?
a cartilage rod that runs under the nerve chord to support it
The name for the animal in the cephalochordates is
lancelets
Where are lanclets found? What body structure is persistent in adults?
shallow sandy bayspersistent notochord in adults
The muscles of the body is divided up into V-shaped blocks called
myomeres
since the notochord is not compressible, the body of lancelet ____ to swim/move
bends
The three groups of animals under the clade Urochordates are ____
tunicates (sea squirts)ThaliaceansLavaceans
What is different about the larval to adult stage of tunicates (urochordates) ?
adults are sessilenerve and notochord dissapear
Bodies of tunicates are covered by a ____. and have a ____-like body with ___ siphons
tunicsac-liketwo siphons
Tunicates have an enlarged pharynx called the ___
pharyngeal basket
How do Tunicates feed?
suspension feeding
What is the Ascidian genome project?
80% of Ciona genes are found in humans (thats why we’re related to chordates)
What is the “2R Hypothesis”
that the genome replicated twice during chordate evolution that leads to vertebrates
In vertebrates the notochord is replaces by
a vertebral column
the first vertebrates lacked ___ and include what two animals?
lacked jawshagfishlamprey
T/F: hagfish have vertebrae
FALSE - even though they were the ancestra vertebrates…..
