Question

part vi: echinoderms
true or false: correct the false statements.

a) echinoderms have a distinctive head. f

b) echinoderms have a mesodermal skeleton t

c) the larval stage of echinoderms are radially symmetrical f

d) sea urchins belong to the class asteroidea f

e) many echinoderms are predatory. t

f) sea cucumbers are echinoderms. ______

Explanation:

a) Echinoderms are radially symmetrical as adults and lack a distinct head; the statement is false, and the corrected statement is "Echinoderms do not have a distinctive head."
b) Echinoderms have an endoskeleton derived from mesoderm; the statement is true.
c) Echinoderm larvae are bilaterally symmetrical, while adults are radially symmetrical; the statement is false, and the corrected statement is "The larval stage of Echinoderms are bilaterally symmetrical."
d) Sea urchins belong to Class Echinoidea, not Asteroidea (which includes starfish); the statement is false, and the corrected statement is "Sea urchins belong to the Class Echinoidea."
e) Many echinoderms like starfish are predatory; the statement is true.
f) Sea cucumbers are part of the phylum Echinodermata, in Class Holothuroidea; the statement is true.

Answer:

a) F; Corrected: Echinoderms do not have a distinctive head.
b) T
c) F; Corrected: The larval stage of Echinoderms are bilaterally symmetrical.
d) F; Corrected: Sea urchins belong to the Class Echinoidea.
e) T
f) T