FREE NEET Biology Practice MCQ Test: Environmental Issues Exercise 3 Questions Answers With Detailed Explanations [PDF]

Answer: (c)

Answer: (d)

Ozone ($O_3$) is a secondary pollutant as it is formed by reaction amongst primary pollutants. On the other hand, $SO_2$ is a primary pollutant. These pollutants persist in the environment in the form they are passed into it. CO is qualitative pollutant. It is considered a pollutant only when its concentration reaches beyond a threshold value in the environment. $CO_2$ is a quantitative as well as a primary pollutant.

Answer: (a)

Stone flies are not bio indicators. Bio indicators provide a range of techniques to assess the impacts of air pollution from reactive nitrogen (N) compounds on statutory nature conservation sites. They complement physical monitoring of atmospheric concentrations and deposition and risk assessment based on the critical loads approach by providing site-based information on atmospheric nitrogen concentrations, nitrogen deposition and/or ecological impacts.

Answer: (b)

Answer: (d)

Marsh gas is another term for methane, produced by plants decomposing under water.

Answer: (b)

This conference occurred from 20 Nov to 8 December, 2012 to extend the life of the Kyoto Protocol at Doha in Qatar.

Answer: (d)

Answer: (d)

Depletion of stratospheric zone enables the UV-radiations to reach the earth's surface. The exposure to these radiations has increased the occurrence of skin cancer, snow blindness (damage to eyes), herpes and deficient functioning of immune system, etc. Liver cancer is not a consequence of UV exposure, it is a pathogen induced, health or life style induced disease.

Answer: (d)

Answer: (c)

Answer: (c)

Answer: (a)

This option represents the incorrect pair and can be corrected as

Phosphorus encourages the growth of aquatic organisms. Rest other options are correctly matched.

Answer: (a)

The amount of biodegradable organic matter in sewage water can be estimated by measuring biochemical oxygen demand. Biochemical Oxygen Demand (BOD) is the amount of oxygen used for biochemical oxidation by microorganisms in a unit volume of water. Polluted water has high BOD. Thus, when sewage gets mixed with river water, its BOD will increase.

Answer: (a)

Euro-III norms were stipulated to control sulphur content at 350 ppm in diesel and 150 ppm in petrol.

Answer: (a)

Answer: (d)

Answer: (d)

Soil conservation is to conserve fertile soil from the losses like heavy rainfall, drainage, high wind, flood, drought etc. Soil is the top cover of the Earth in which plants can grow. The rotation of crops, contour ploughing and use of proper fertilizers help in maintaining the fertility of soil. Plantation of trees, controlled grazing of grasslands, reforestation, prevention of forests fires will protect the erosion of topsoil. The regulation of water resources to prevent flood will help not only in soil conservation but also supply an adequate water supply in the period of drought.

Answer: (d)

Answer: (d)

Answer: (a)

Phosphate is an important compound of fertilizer which are added to crop fields and then are passed down to water bodies during rains through runoff. It is also present in sewage that is dumped into the water body. This nutrient bring about dense growth of water plants especially the algae and cause algal bloom. This algal bloom leads to oxygen depletion in water bodies and causes death of aquatic life.