test 3 Flashcards
what are the deuterostomes?
echinoderms
hemichordates
chordates
fish
reptiles
amphibians
mammals
primates
what makes deuterostomes different
anus develops from the blastophore
radius cell cleavage
what are examples of echinoderms
starfish
sand dollars
what does echinoderm mean?
echino - spiny
derm - skin
How does the echinoderm’s body plan shift during development?
larvae - bilateral symmetry
adults - pentaradial symmetry
Echinoderms have this type of skeleton
endoskeleton
what are the two surfaces of echinoderms?
aboral surface - spiny side (madreporite)
oral surface - mouth side (mouth angle plates)
what are ossicles?
calcium-rich plates
how is the endoskeleton formed?
ossicles compiled together with perforated pores with modifiable collagenous tissue surrounding them
what is the water-vascular system?
a hydraulic system that aids in movement and feeding
what is the structure of the water-vascular system?
central ring with a madreporite that pushes water into the radial canals of each segment.
changes in water pressure allow for the ampulla to engage / move tube feet.
what is the meadroporite?
opening for water entry
what is the ampulla
muscular sac for tube feet control
how does the echinoderm coelom aid the starfish?
circulation and respiration through papulae extensions
how do echinoderms reproduce?
small % asexually repro by splitting and reaggregation
most take part in external sexual repro
how come we know so much about the extinct classes of echinoderms?
skeleton allows for fossilization
how do hemichrodates differ from chordates?
hemi - pharyngeal gill slot & hollow dorsal nerver cord
chordates - notocord, postanal tail, pharyngeal gill slot & hollow dorsal nerver cord
what are the three divisions of chordate phylum?
urochordata
Cephalochordata
vertebrata
what are the two invertebrates subphylum?
urochordata
cephalocordata
what are the 4 distinct evolutions of chordates?
nerve cord
notocord
pharyngeal slits
postanal tail
what does the nerve cord turn into?
brain and spinal cord
what does the notocord turn into?
spinal column in vertebrates
what does the pharyngeal slit do? what did it evolve into?
connects the pharynx with outside
used to be gill slits
what are examples of the urochordates?
tunicates
what are the characteristics of subphylum urochordata?
marine
sessile - attach to substrate and develop into filter-feeders
obtain food by ciliary action
larvae exhibit basic characteristics of chordates but do not maintain through lifecycle
what is an example of a cephalochordate?
lancelet
characteristics of the cephalocordates?
marine
not sessile but spend most time burrowed in sand
filter feeding
notocord and nerve cord present throughout life
what are examples of the subphylum vertebrata
hagfishes
lampreys
jawed vertebrates
who are the vertebrates?
fishes
amphibians
reptiles
birds
mammals
what is the neural crest? what are the embryonic cells?
a unique group of embryonic cells that forms many vertebrate structures / helps lay pattern for vertebral column.
blastula / glastula cells
what are the three characteristics of vertebrates?
neural crest
internal organs
endoskeleton
what is the endoskeleton made of? why is it important?
cartilage or bone
allows for large body growth and movement
saves energy by not having to molt
characteristics of fish
vertebral column
jaws and paired appendages
internal gills
single-loop blood circulation
nutritional deficiencies
fusiform body shape
why do gills close when a fish is out of water?
oxygen cannot be taken from the air, gills close, mucous is secreted over the gills to prevent drying out.
what is an agnatha
jawless fish
what do hagfish eat? what do lampreys eat?
hagfish - dead things
lampreys - live things
what did jaws develop from?
anterior gill arches made of cartilage
what are the two classes of agnatha? what does agnatha mean?
jawless vertebrates
hagfishes and lampreys
what is the hagfish’s defense mechanism?
excretion of slime that keeps the skin wet
what are the characteristics of lampreys?
no jaws, circular rows of teeth
dorsal and caudal fins - more movement
predatory - attach to live prey and feed on tissue
what is the evolutionary benefit of jaws?
allows organisms to predate larger organisms thanks to being able to bite
jaws/masseter muscles allow for organism to return to fusiform shape for increased hydrodynamic movement
what are the examples of chondrichthyes?
sharks, rays, skates
what are the characteristics of chondrichthyes?
jawed fish
paired fins
paired nostrils
scales
two-chambered heart
skeleton made from cartilage
do sharks have a real brain? why or why not?
yes, there are regions of the brian designed for special functions
what is a shark’s liver filled with and why?
oil
maintains buoyancy
to move up or down the water column a shark must keep moving and angle their fins up or down like a gliding airplane.
what is a spiral valve? why is it important?
a part of the digestive tract that mixes chyme
moving chyme through a spiral keeps it there for longer allowing and increases surface area in the tract