OESOPHAGUS STOMACH
ECHINODERMS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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TRUE, they rely on their ventral muscular foot
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FALSE, they rely on their tubular foot
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Either A or B
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None of the above
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Detailed explanation-1: -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.
Detailed explanation-2: -The correct answer is (b). Echinoderms do not have gills.
Detailed explanation-3: -The tube feet of echinoderms move and handle food using a hydraulic system. “Something similar happens in echinoderm tube feet–small, soft, unjointed, and exceedingly numerous organs used for locomotion, handling food, and similar functions, noticeable when a starfish creeps up the glass wall of an aquarium.
Detailed explanation-4: -With a few exceptions, echinoderms are all benthic (bottom-dwellers); most Paleozoic echinoderms were sessile, while most living echinoderms can creep from place to place.