Environmental Science MCQ – Asked in Previous Years, WBCS Mains

Answer – A. Amrita Devi
Explanation-
▪ Amrita Devi was associated with the Bishnoi movement. The Bishnoi community, founded by Guru Jambheshwar in the 15th century, is known for their conservation efforts and protection of nature and wildlife. Amrita Devi, along with several other Bishnoi men and women, sacrificed their lives while protecting Khejri trees from being cut down during the 18th-century in the Bishnoi village of Khejarli. Their sacrifice symbolizes the commitment of the Bishnoi community towards environmental conservation.

Answer – A. Montreal
Explanation-
▪ The conservation of ozone depletion was discussed in the Montreal Protocol. The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production and consumption of ozone-depleting substances (ODS). It was agreed upon in Montreal, Canada, in 1987 and has been successful in significantly reducing the production and use of ODS, such as chlorofluorocarbons (CFCs) and halons.

Answer – B. Insects and Cattle
Explanation-
▪ Insects and cattle belong to the category of primary consumers. Primary consumers, also known as herbivores, are organisms that directly feed on producers (plants or algae) as their source of energy. Insects, such as grasshoppers and caterpillars, primarily feed on plants. Cattle, such as cows and goats, consume plant material as their main food source.

Answer –D. Both A. and B. (Algal bloom and Eutrophication)
Explanation-
▪ Algal bloom and eutrophication are both terms that describe the profuse growth of aquatic vegetation that often changes the color of a water body.

▪ Algal bloom is specifically the rapid growth of microscopic algae, while eutrophication is the process by which a water body becomes enriched with nutrients, leading to algal blooms.

▪ Algal blooms can be caused by a number of factors, including excess nutrients from fertilizers, sewage, or runoff from farms. They can also be caused by warm water temperatures and sunlight.

▪ When algae blooms occur, they can often change the color of the water, making it look green, yellow, or red. In some cases, algal blooms can produce toxins that can harm fish and other aquatic life.

▪ Eutrophication is a natural process, but it can be accelerated by human activities. When nutrients are added to a water body, they can stimulate the growth of algae. This can lead to algal blooms, which can have a number of negative effects, including:

• Decreasing the amount of oxygen in the water, which can kill fish and other aquatic life.
• Producing toxins that can harm people and animals.
• Clouding the water, making it difficult for sunlight to reach the bottom of the water body.
• Reducing the diversity of plant and animal life in the water body.

▪ Algal blooms and eutrophication are serious environmental problems that can have a significant impact on water quality. There are a number of things that can be done to prevent these problems, including:

• Reducing the use of fertilizers and manure.
• Treating sewage before it is released into waterways.
• Controlling runoff from farms and other areas.
• Planting trees and shrubs along waterways to help filter nutrients from the water.

By taking these steps, we can help to protect our waterways from algal blooms and eutrophication.

Answer – C. Mercury
Explanation-
▪ Minamata disease in Japan was the result of water pollution by mercury. Minamata disease was a neurological syndrome caused by the consumption of seafood contaminated with methylmercury, which was discharged into Minamata Bay by a chemical plant. The disease resulted in severe health effects, including neurological disorders, birth defects, and even death, among the affected population.

Answer – D. All of the above
Explanation-
▪ Chlorofluorocarbon (CFC) is used in various applications, including refrigerators, air conditioners, and perfumes. CFCs were commonly used as coolants and propellants in these products due to their stability and non-toxic nature. However, it was later discovered that CFCs contribute to ozone depletion in the upper atmosphere, leading to the development of the Montreal Protocol to phase out their production and use.

Answer –C. Nuclear energy
Explanation-
▪ Nuclear energy is not considered a biomass energy source. Biomass energy refers to the energy derived from organic materials such as wood, agricultural residues, and animal waste.

▪ Nuclear energy, on the other hand, is obtained through nuclear reactions in which the nucleus of an atom is split (nuclear fission) or combined (nuclear fusion) to release a large amount of energy. It does not involve the use of organic materials.

Answer –C. Reducing agent
Explanation-
▪ OH radicals are highly reactive and can react with many different pollutants in the atmosphere, including carbon monoxide, methane, and ozone precursors. This helps to remove these pollutants from the atmosphere and improve air quality.

Answer – C. Activated sludge process
Explanation-
▪ The widely-used aerobic suspension type of liquid waste treatment system is the activated sludge process. In this process, wastewater is mixed with a microbial culture (activated sludge) containing aerobic bacteria.

▪ The mixture is aerated to provide oxygen for the bacteria, which consume and break down the organic matter in the wastewater. The activated sludge process is efficient in removing organic pollutants and nutrients from wastewater, producing treated water that can be safely discharged or reused.

Answer – A. 1984
Explanation-
▪ The first National Ambient Air Quality Standards (NAAQS) for major pollutants were notified by the Central Pollution Control Board (CPCB) in 1984. These standards were revised in 1994 and 2009.

▪ The NAAQS are designed to protect human health and the environment from the harmful effects of air pollution. They set limits on the concentrations of pollutants in the air, and they are used to assess the quality of air in different parts of the country.