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11 Cards in this Set

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How does a sea star move? Explain in terms of the water vascular system of echinoderms.
A sea star moves by regulation of its water vascular system. Tube feet attach to a surface, the sea star moves itself forward, and the suction is released
Describe the differences in symmetry between larval echinoderms and adult echinoderms.
Larval echinoderms are bilaterally symmetrical, whereas adult echinoderms are radially symmetrical
How are sea cucumbers different from other echinoderms?
Sea cucumbers are tubular and have a leathery outer covering, which allows them flexibility, instead of hard plates
What evidence suggests that echinoderms are closely related to chordates?
Both echinoderms and chordates show deuterostome development
How do the various defense mechanisms among the echinoderm classes help deter predators?
The rigid endoskeleton helps protect echinoderms from their enemies. Spines and poison glands also protect echinoderms. Adult echinoderms move by walking, whereas larval forms are free swimming. If an echinoderm such as a sea star loses part of a ray, it can be regenerated. Sea cucumbers can expel their digestive tracts and grow new ones.
long tapered arms of some echinoderms that are covered with short, rounded spines.
pincerlike appendages on echinoderms used for protection and cleaning.
in echinoderms, the hydraulic system that operates under water pressure; aids in locomotion, gas exchange, and excretion.
water vascular system
in echinoderms, the sievelike, disk-shaped opening through which water flows in and out of the water vascular system; helps filter out large particles from entering the body.
in echinoderms, hollow, thin-walled tubes that end in a suction cup; part of the water vascular system, they also aid in locomotion, gas exchange, and excretion.
tube feet
in echinoderms, the round, muscular structure on a tube foot that aids in locomotion.