OESOPHAGUS STOMACH
ECHINODERMS
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Papulae
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Ampullae
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Polian vesicles
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Pedicellariae
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Detailed explanation-1: -Excretion in echinoderms is by simple diffusion of metabolic wastes (ammonia) across thin permeable regions of the body wall. A variety of gas exchange structures, including the tube feet, is found in various echinoderms.
Detailed explanation-2: -Echinoderms have a unique system for gas exchange, nutrient circulation, and locomotion called the water vascular system. The system consists of a central ring canal and radial canals extending along each arm. Water circulates through these structures allowing for gas, nutrient, and waste exchange.
Detailed explanation-3: -In general, echinoderms typically respire by simple diffusion, using gills or specialized projections, like tube feet or pockets, to circulate water and oxygen through their bodies. Many echinoderms also use a simple hemal system, a series of pockets and tubes that serves almost like a net of veins and arteries.