Tag: global environmental change

Questions Related to global environmental change

Global warming can be controlled by 

  1. Reducing reforestation, increasing the use of fossil fuel

  2. Increasing deforestation, slowing down the growth of human population

  3. Increasing deforestation, reducing efficiency of energy usage

  4. Reducing deforestation, cutting down use of fossil fuel


Correct Option: D
Explanation:

Global warming is the biggest challenge for the developing countries like India. The rapid increase in human population and the increased levels of pollution are the major contributors of global warming.The percentage of heat-trapping carbon dioxide (CO$ _2$) increases due to the burning of  fossil fuels to generate electricity, fuel our cars, and heat our homes. Deforestation also increases the concentration of carbon dioxide in the atmosphere.

So, the correct answer is option D.

Excess of carbon dioxide in the atmosphere leads to 

  1. Global warming

  2. Ozone depletion

  3. Acid rain

  4. None of the above


Correct Option: A
Explanation:

Modern human activities are responsible for the release of huge quantities of CO$ _2$ in the atmosphere. The major activities, which contribute towards this, are burning of fossil fuels and cultivation of the soil. Although CO$ _2$ is not considered as a pollutant, an increase in its proportion in the atmosphere can lead to global warming through increased greenhouse effect. 

Which of the following defines the effect of deforestation on the next generation?

  1. Global warming

  2. Global cooling

  3. Both A and B

  4. None of the above


Correct Option: A
Explanation:
As a result of deforestation, chances of desertification, droughts, floods, etc. increase. Deforestation can also increase the level of carbon dioxide in the Earth, it will lead to an increase in temperature i.e., global warming. As a result, the entire natural water cycle will get disrupted. This again increases the risk of natural calamities.
Thus, the correct answer is option A.

Chernobyl nuclear tragedy occurred in

  1. April, 1986

  2. August 6, 1945

  3. August 9, 1945

  4. December 3, 1984


Correct Option: A
Explanation:

The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the Chernobyl nuclear power plant in Ukraine. In this accident, large quantities of radioactive particles were released into the atmosphere, which spread over much of the western USSR and Europe. It was the worst nuclear accident in history.

Environment is warmed up by

  1. Water vapour

  2. Methane

  3. $CO _2$

  4. All of the above


Correct Option: D
Explanation:

The greenhouse effect is caused by the greenhouse gases. The gases methane, carbon dioxide, and water vapour trap the solar radiations which need to be reflected back to the atmosphere and increase the temperature of the earth. The greenhouse is considered as the direct cause of global warming.

Thus, the correct answer is option D. 

Presence of CFCs in the atmosphere is responsible for

  1. Formation of ozone

  2. Production of healthy plants

  3. Depletion of ozone layer

  4. None of these


Correct Option: C
Explanation:

CFCs are used as coolants in refrigerators, coolers, etc. The CFCs causes the breaking of the ozone molecule which forms the oxygen radical and O$ _2$. So, the presence of CFCs in the atmosphere results in the depletion of the ozone layer and allowing the penetration of the harmful UV radiations from the sun into the Earth's atmosphere. 

Thus, the correct answer is option C. 

What immediate hazard is likely to occur if the temperature of the earth rises by 5$^oC$?

  1. Increase in productivity

  2. Melting of polar ice

  3. Destruction of phytoplanktons

  4. Inundation of coastal towns


Correct Option: B

What is the potential danger of greenhouse effect?

  1. Poor photosynthesis

  2. Heavy rainfall

  3. Coastal flooding

  4. More humidity in environment


Correct Option: C

Which of the following does not contributes to greenhouse effect?

  1. Carbon dioxide

  2. Carbon monoxide

  3. Chloro-fluoro carbon and Methane

  4. Refrigerant freon


Correct Option: B
Explanation:
Greenhouse gases are the compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere. Popular of them are carbon dioxide, methane, chloro-fluoro carbon, nitrous oxide, freon and ozone while carbon monoxide is silent killer gas
So, the correct answer is option B.

Ultraviolet light causes

  1. Destruction of hydrogen bonds between complementary DNA strands

  2. Photodynamic action

  3. Sticky metaphases

  4. Formation of pyrimidines


Correct Option: A
Explanation:
DNA is one of the prime molecules and provides stability for proper functioning and existence of all living systems. Ultra-violet radiations are power molecules whose exposure breaks the hydrogen bonds of dna and thus altering its structure and affecting the genomic stability.
So, the correct answer is option A.