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Coelenterata

Assertion A: ...

Question

Assertion (A): Coelenterates may form corals.
Reason (R): Coelenterates possess hard calcareous exoskeleton.

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Solution

Correct option: (d). Assertion(A) is false and reason(R) is true.

$∙$ Corals belong to the phylum Coelenterata/Cnidaria.
$∙$ Organisms belonging to this phylum usually possess calcareous exoskeleton.
$∙$ For example, some organisms of phylum Cnidaria secrete an exoskeleton of calcium carbonate (CaCO3) around them to form a hard skeleton or shell.
$∙$ Corals have a skeleton composed of calcium carbonate.

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