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(16) Unlike that of most other members of the bilateria, the nervous system of t

ID: 3484333 • Letter: #

Question

(16) Unlike that of most other members of the bilateria, the nervous system of the

echinoderms is characterized by very little ______________________________ .

(17) Although presumably homologous with the vertebrate thyroid gland, the

endostyle of the Ascidiacea produces ___________________________________

instead of thyroxine.

(18) A rather dramatic form of autotomy (the casting off of body parts) is the

phenomenon of _____________________________________________________

that is typical of many species of Holothuroidea.

(19) Among the so called oligomerous phyla the mesosome has a unit of coelomic

cavity within it referred to as the ______________________________________ .

(20) The sessile adult nature of the sea squirts does not prevent dispersion of

subsequent generations since these animals have free swimming ______________

larvae in their life cycle.

(21) The lophophore apparatus of the bryozoans and other lophophorates

functions primarily as a device for _____________________________________ .

(22) The invagination of ectoderm at the anterior of the gut tube during

development results in the formation of _________________________________

which in the case of arthropods means that the lining of this portion of the gut is

lost at each molt. (22 points)

*Regarding marine biology of Tropical Marine Invertebrates*

Explanation / Answer

(16) Unlike that of most other members of the bilateria, the nervous system of the echinoderms is characterized by very little developed.

(17) Although presumably homologous with the vertebrate thyroid gland, the endostyle of the Ascidiacea produces L-thyroxine(T4)  instead of thyroxine.

(18) A rather dramatic form of autotomy (the casting off of body parts) is the phenomenon of Evisceration that is typical of many species of Holothuroidea.

(19) Among the so-called oligomerous phyla, the mesosome has a unit of a coelomic cavity within it referred to as the schizocoelom.

(20) The sessile adult nature of the sea squirts does not prevent dispersion of subsequent generations since these animals have free swimming bisexual larva larvae in their life cycle.

(21) The lophophore apparatus of the bryozoans and other lophophorates functions primarily as a device for capturing food.

(22) The invagination of ectoderm at the anterior of the gut tube during development results in the formation of archenteron which in the case of arthropods means that the lining of this portion of the gut is lost at each moult.