Why is coral classified as an animal rather than a plant?

Answer: It catches small prey with tentacles and digests it.

It makes its own sugars from sunlight. — Wrong. Corals often need sunlight, but the light is used by algae living inside their tissues, not by the coral animal itself. The coral polyp cannot make its own sugars from sunlight; it must take in food. That is one reason it is classified as an animal.

It catches small prey with tentacles and digests it. ✓ — Correct! A coral is made of tiny animals called polyps, which use stinging tentacles to capture small prey and digest it. Unlike plants, they cannot make their own food through photosynthesis. They must eat to survive, which is an animal trait.

It stays rooted in one place and grows hard branches. — Wrong. Many corals do stay fixed in one place and can look like branching plants. But staying still is not what makes something a plant; many animals are sessile. What makes coral an animal is that its polyps capture and digest food.