The answer is a Vagus Nerve.
DDT was used during second world war to control malaria among the troops and the civilians. Later, it was used as pesticide in agricultural and household practices. Due to its excessive use it entered into the food chain and its amount in the food crossed the permissible level. So, it was banned by United States.
Coral reefs are found in the photic zone of aquatic biome.
Explanation:
The ridges of ocean that are formed by invertebrates of marine system which lives in the superficial warm water are the Coral reefs. These are found in the ocean zone- photic. This is the uppermost surface area of ocean where abundance of sunlight is found and photosynthesis takes place.
The reefs of shallow water have an association with algae, which is photosynthetic. One of such reefs is the Reef of Great Barrier in the Australian northeast coast.
Not all reef building corals can form in the tropics especially where rivers bring in a lot of silty sediment, which is uncommon to corals.
