Answer: C

Explanation:

Photosynthesis is a process in which plants use sunlight to produce oxygen, carbohydrates (glucose) and other nutrients by combining carbon dioxide and water. Plants take energy from the sun, carbon dioxide from the atmosphere through leaves and water from the soil through roots. Hence, statement 1 is correct.

Photosynthesis is supported by the green pigment (chlorophyll) present in the plant. Chlorophyll contains magnesium which gives the plant the ability to convert light into energy. This process can be described as follows.

Carbon dioxide + water + solar energy → carbohydrates + oxygen

Hence, statement 2 is correct.

Answer: B

Explanation:

Photosynthesis is the basic source of life and energy for all living organisms. The oxygen produced in it is life-sustaining for humans and animals. Photosynthesis requires light and nutrients, both of which are scarce in the deep ocean. Thus, this process takes place only in the upper layers of the ocean (from the surface to a depth of about 75 meters). Hence, statement 1 is incorrect.

Sunlight does not reach the depths of the oceans, so another process takes place here which is called chemical synthesis. This process occurs around hydrothermal vents and uses chemicals instead of solar energy as an energy source. In this process, glucose and sulfur compounds are produced by green sulfur bacteria by combining hydrogen sulphide, carbon dioxide and oxygen. Hence, statement 2 is correct.

Answer: C

Explanation:

At the first level, producers are eaten by organisms, which are called primary consumers. For example, rabbits, goats etc., which eat plants, are primary consumers also called herbivores. Hence, pair 1 is correctly matched.

At the next level are secondary consumers who feed on primary consumers. For example, lions that eat deer. Hence, pair 2 is correctly matched.

At the third level are tertiary consumers that use secondary consumers as food. For example, hawks are tertiary consumers that eat snakes. Tertiary consumers can be eaten by other consumers and the chain continues. Hence, pair 3 is correctly matched.

Answer: C

Explanation:

An herbivore eats detritus, which includes organic waste, debris, and dried animal feces. Examples of detritivores are flies, cockroaches, crabs, earthworms, termites and wood ants. Both decomposers and detritivores help in the disintegration or decomposition of dead and decaying matter. Both obtain their energy from waste materials. Without their contribution the earth would be filled with dead matter and dead bodies. While herbivores actually eat the waste material, decomposers secrete enzymes to digest the waste and then absorb the released molecules. Decomposers perform another additional function as compared to herbivores. They return essential nutrients to the ecosystem. Hence, option (c) is correct.

Answer: A

Explanation:

Ex-situ conservation is a process by which extinct species of plants and animals are conserved away from their natural habitat. There are two methods of ex-situ conservation: first, endangered species are reared in zoological parks and second, live sperm and egg samples are preserved in liquid nitrogen at extremely low temperatures.