Echinoderms and Chordates (Invertebrates part two) Flashcards
What are the main characteristics of the Echinodermata Phylum?
Adults follow radial symmetry
larva have bilateral symmetry during development
What are some echinoderms from the 6 classes?
sea stars and starfish brittle stars sea urchins and sand dollars sea cucumbers feather stars sea daisies
What characteristics do echinoderms share?
they are coelomates and deuterostomes with radial symmetry attached to a central disk
lack of cephalization, have a simple nerve net
endoskeleton: internal calcareous plates for support
epidermis: thin, so skeletal spins and bumps are felt on surface
What do echinoderms have for locomotion, feeding, and gas exchange?
Water vascular system: branching hydraulic canals
tube feet: extensions for suction, feeding, moving, and gas exchange
sessile or slow moving predators
What are characteristics of Chordata?
Bilateral
Triploblastic
Coelomates
Deuterostomes
What are the four derived characteristics of Chordates?
Notochord
Dorsal, Hollow Nerve Cord
Pharyngeal Slits/Clefts
Post-Anal Tail
What is the notochord?
long, flexible rod of Mesoderm tissue
provides skeletal support
What is the dorsal hollow nerve cord?
Never cord develops from a plate of ectoderm that rolls into hollow neural tube
it is dorsal to notochord during development
Becomes central nervous system
What are pharyngeal slits/clefts?
grooves on the side of pharynx
functions as a gas exchanger in form of gills
For tetrapods, they develop into ear, jaw, head, and neck
What is the post-anal tail?
tail that is posterior to anus
tail is greatly reduced during embryonic development
contains skeletal elements and muscles
What are characteristics of the vertebrates clade?
have a backbone that replaces the notochord
more complex skeletal system
more complex nervous system
What is a signature feature of vertebrates?
vertebral column encloses the spinal cord
What gives vertebrates unique structures?
Neural crest cells
migrate to different regions for skull, sensory neurons, and teeth
What two classes are vertebrates but not very representative of it? Why?
Myzini and Petromyzontida
have rudimentary vertebra, but not a full backbone
classified as vertebrates because of DNA data
What is a defining characteristic of Myxini and Petromyzontida?
They lack jaws and use sucking mouths and rows
Hagfish and Lampreys
