Question

Which among the following is true about corals?

• A. They are poriferans that are attached to some solid support.
• B. They are cnidarians that are solitary living beings.
• C. They are poriferans residing at sea bed.
• D. They are cnidarians that live in colonies.

Answer 1

The correct option is D They are cnidarians that live in colonies.

$\bullet$ Corals are placed in the phylum Coelenterata.
They are aquatic organisms with body cavity. Their body is differentiated into two layer of cells. Some of the cnidarians like hydra lives solitary, whereas others like corals live in colonies.
$\bullet$ Poriferans are most primitive organisms under the kingdom Animalia. They are non-motile organisms, attached to a solid support. These organisms are mostly marine. E.g., Euplectella.