Answer: B

Explanation:

Black carbon (BC) is a component of fine particulate matter. Black carbon consists of pure carbon in several linked forms. It is formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot. Black carbon causes human morbidity and premature mortality. In climatology, black carbon is a climate forcing agent. Black carbon warms the Earth by absorbing sunlight and heating the atmosphere and by reducing albedo when deposited on snow and ice. In the tropics, black carbon in soils significantly contributes to fertility as it is able to absorb important plant nutrients. Hence, statement 3 is incorrect.

Answer: B

Explanation:

Corals that inhabit the colder deep waters of continental shelves and offshore canyons, ranging from 50 to over 1000m depths lack zooxanthellae and may build reef-like structures or occur solitarily. Cold-water corals are different from their warm-water counterparts because they do not contain symbiotic algae for photosynthesis and grow more slowly. Cold-water corals obtain all their energy from organic matter and zooplankton, which they catch from the currents drifting past. Cold-water corals can be found over a wide range of latitudes, from tropical to Polar Regions, and from the shallow to the deep seas. Hence, statement 1 is incorrect.

Answer: D

Explanation:

Bioremediation refers to the use of specific microorganisms or plants to metabolize and remove harmful substances. These organisms are known for their biochemical and physical affinity to hydrocarbons among other pollutants. Various types of bacteria, archaea, algae, fungi, and some species of plants are all able to break down specific toxic waste products into safer constituents. Hence, all are correct.

Answer: C

Explanation:

In contrast to humans and other animals, plants can produce glucose through a process known as photosynthesis. The green parts of plants use sunlight, water, and the gas carbon dioxide from the air to produce glucose and oxygen. Hence, option (c) is correct.

Answer: D

Explanation:

The roots of pulses and legumes contain soil enriching bacteria collectively known as Rhizobium. Therefore pulses perform biological fixation of environmental nitrogen. They also increase organic matter in the soil, improve quality and maintain its biodiversity. Pulses enhance fertility and reduce the consumption of major fertilisers required for the cultivation of food crops by millions of tonnes globally. Hence, all statements are correct.