Echinodermata Flashcards
Body symmetry of Echinodermata is
bilateral as larvae and radial as adults
Echinodermata are (aceolomates or eucoelomates)
eucoelomates
Echinodermata (are/are not) segmented
are not
Echinodermata are the first that we studied that are
deuterostomes
Deuterostome blastopheres become ____ first
anus
An important characteristic of Echinodermata is their _______ which is derived from _______ and composed of __________
endoskeleton mesoderm calcareous plates (ossicles)
Echinodermata have _______ digestive systems
complete
Echinodermata have _______ circulatory system
open
The external projections of ossicles in sea stars are called
dermal spines
The minute pincher-like organs of sea stars are called
pedicellariae
The function of pedicellariae are
to keep off encrusting organisms
These structures function to help with respiration on sea stars
dermal branchiae (skin gills)
The water vascular system of sea stars function is
locomotion
The water flow process of sea stars is…
- the madreporite 2. the stone canal 3. the ring canal (that encircles the mouth) 4. radial canal (in each arm) 5. lateral canal (side of arms) 6. ampullae (base of tube feet) 7. tube feet or podia (extend and retract)
When looking at sea star slides, the unfertilized eggs have
a nucleus and nucleolus
When looking at sea star slides, the fertilized eggs have
a membrane
When looking at sea star slides, the blastula has
a middle blastocoel
When looking at sea star slides, the late gastrula has
a blastocoel and second cavity (archenteron)
The endoderm germ layer
lines the digestive tract
The mesoderm germ layer
becomes the muscle, skeleton, reproductive system
The ectoderm germ layer
becomes the skin and nervous system
Sea stars are part of the class
Asteroidea
Brittle stars are part of the class
Ophuiroidea
Sea Urchins are part of the class
Echinoidea
Sea cucumbers are part of the class
Holothuroidea
Which stage of sea star embryology is shown?
The unfertilized egg
Which stage of sea star embryology is shown?
The fertilized egg
Which stage of sea star embryology is shown?
late gastrula
Which stage of sea star embryology is shown?
Two-cell stage
Which stage of sea star embryology is shown?
Blastula
Pictured are ______ which are found on ______.
They function to _____
pedicellaraie
sea stars
keep animals from attaching to body surface
Pictured is _____
In this stage it shows _____ symmetry, but in adulthood shows _______ symmetry.
Sea Star larvae
bilateral
radial
Identify the structures indicated by pins.
White - Ambulacral ridge
Yellow- pyloric caecum
Green- stomach
