Question

Corals are:

• A. Poriferans attached some solid support
• B. Cnidarians are solitary living
• C. Poriferans present at the sea bed
• D. Cnidarians that live in colonies

Answer 1

The correct option is D

Cnidarians that live in colonies

The correct option is option D.

Explanation for correct options:

1. Corals belong to the phylum Cnidaria.
2. They grow in colonies.
3. The corallites of individual colonies fuse together to form a hard skeleton mass called corallium.
4. They grow in temperate and subtropical areas.
5. They can form extensive masses called coral reefs.

Explanation for incorrect options:

Option A:

1. Phylum Porifera includes pore-bearing animals.
2. They remain attached to submerged objects and rocks.

Option B:

1. Phylum cnidaria includes the true metazoans that have a tissue level of organization.
2. They may be solitary living or colonial.

Option C:

1. Phylum Porifera includes pore-bearing animals.
2. They remain attached to submerged objects in the sea bed.

Final answer: Corals are cnidarians that live in colonies.