OESOPHAGUS STOMACH
ECHINODERMS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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True
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False
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Either A or B
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None of the above
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Detailed explanation-1: -Echinoderms possess five-sided radial symmetry – think five arms of a starfish – but have bilaterally symmetrical larvae. They include both sessile (not moving) and motile representatives.
Detailed explanation-2: -The correct answer is (b). Echinoderms do not have gills.
Detailed explanation-3: -Sessile Echinoderms: Classes Crinoidea & Blastoidea. The sessile (immobile) classes are the crinoids (sea lilies) and the blastoids. Of these, only crinoids still live today. These forms look more like plants than animals (Figure 8.11).
Detailed explanation-4: -An echinoderm moves by using many tube feet. Tube feet are small, delicate projections attached along the side of a water-filled tube called a radial canal. Figure 3.85 shows some examples of echinoderm tube feet. Tube feet extend through the small holes in the skeleton to the outside.