Tag: human influences on the environment

Questions Related to human influences on the environment

Assertion :Green - house effect is due to thick layer of carbon dioxide.

Reason :The glass panels of a green - house allowing the sunlight to filter through but preventing the heat from being re-radiated in outer space.

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true

Show answer
Correct Option: B

Which one of the following is not a green house gas?

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. $CO _2$

  2. $CH _4$

  3. $O _2$

  4. CFCs

Show answer
Correct Option: C
Explanation:

Greenhouse gases are called so because they are capable of absorbing the insolation from the sun and keeping it within the troposphere, thereby increasing the overall temperature of the earth, called global warming. Carbon dioxide, methane, nitrous oxide, ozone, Chlorofluorocarbons and sulphur hexafluoride are considered to be the potent greenhouse gases. Oxygen is not a greenhouse gas.

Hence, the correct answer is 'O$ _{2}$' 

Surface of earth is kept warm by

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. Solar radiations

  2. Geothermal energy

  3. Green house flux

  4. Absorption of infra-radiations by green house gases

Show answer
Correct Option: C
Explanation:

The gases in the troposphere of the atmosphere absorb the sun radiations and trap them so that they do not reflect back. This process allows the heat to remain trapped with in the atmosphere and the earth surface remains warm. This process is called greenhouse effect and the absorbed radiations striking the earth's surface are called green house flux. Carbon dioxide, water vapour, oxides of nitrogen are useful for this purpose. 

Hence, the correct answer is 'Green house flux'.

Green house gases include

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. $CO _2, CHC, CH _4$ and $N _2O$

  2. $CO _2, O _2, N _2, NO _2$ and $NH _3$

  3. $CH _4, N _2. CO _2$ and $NH _3$

  4. $CFC, CO _2, NH _3$ and $N _2$

Show answer
Correct Option: A
Explanation:

A greenhouse gas absorb radiation and emit heat energy maintaining the Earth's temperature. However, when released in excess amounts, they cause global warming. Sources are volcanic eruptions, burning of fossil fuels, deforestation, vehicular exhausts, industrial emissions etc. contribute to the greenhouse gases. Carbon dioxide, Chlorinated hydrocarbon (CHC), Methane and oxides of nitrogen are considered to be the major greenhouse gases.

Hence, the correct answer is 'CO$ _{2}$, CHC, CH$ _{4}$ and N$ _{2}$O'

Maximum green house gas released by which country : -

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. India

  2. France

  3. U.S.A

  4. Britain

Show answer
Correct Option: C
Explanation:
Maximum greenhouse gas is released by China in the world.
China > USA > Britain > India > France.
So, the correct answer is 'Option C-U.S.A'.

Which is not a green house gas?

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. Chlorofluorocarbon

  2. Methane

  3. Carbon dioxide

  4. Hydrogen

Show answer
Correct Option: D
Explanation:
Greenhouse gases cause greenhouse effect by trapping the infrared radiation trying to escape back to space. This process increases the earth’s temperature. Gases which contributes in greenhouse effect are carbon dioxide, methane, nitrous oxide, ozone, water vapour, Chlorofluorocarbons (CFCs) and, Hydrofluorocarbons (HCFCs and HFCs). Hydrogen is not a greenhouse gas.
Hence, the correct answer is ‘Hydrogen’.

Methane gas producing field is

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. Wheat field

  2. Paddy field

  3. Cotton field

  4. Groundnut field

Show answer
Correct Option: B
Explanation:

Paddy or the rice fields are water-logged to allow the growth of the rice crops. Due to the respiration, the carbon dioxide is released in heavy amounts by the bacteria present in the water-logged soil. However, as the season progresses, the methane-releasing bacteria are seen to occupy the paddy field. Together with the carbon dioxide, the methane becomes a greenhouse gas resulting in global warming

So, the correct answer is 'Paddy field'

A green house gas is

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. $H _2$

  2. CO

  3. $CO _2$

  4. $N _2$

Show answer
Correct Option: C
Explanation:

A greenhouse gas absorb radiation and emit heat energy maintaining the Earth's temperature. Sources are volcanic eruptions, burning of fossil fuels, deforestation, vehicular emission, industrial exhausts etc. which have increased the concentration of carbon dioxide in the atmosphere. The oxygen and hydrogen are transparent gases having symmetrical molecules of identical atoms, unable to rotate and vibrate.

Hence, the correct answer is 'CO$ _{2}$'.

Ozone is

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. Protector in troposphere

  2. Pollutant in troposphere

  3. Green house gas

  4. Both B and C

Show answer
Correct Option: D
Explanation:

Ozone is a significant gas in the stratosphere because it absorbs the UV rays and do not allow them to reach the earth's surface. There it is formed by the reaction of oxygen with UV rays. However, tropospheric or ground-level ozone is formed as a secondary pollutant and is harmful. It acts as a major constituent of the photochemical smog. It also traps and reflect back the infra-red rays coming from the earth's surface. Here, it is formed when the primary pollutants react with the oxygen in the presence of sunlight. So, it acts as a greenhouse gas.

Hence, the correct answer is 'Both B and C'.

Substitute of chlorofluorocarbon is

zoology human influences on the environment carbon cycle ozone layer depletion and causes depletion of ozone layer

  1. Hydrofluorocarbon

  2. Hydrochlorofluorocarbon

  3. Fluorocarbon

  4. Both A and B

Show answer
Correct Option: D
Explanation:
Chlorofluorocarbons (CFC) are the chemicals used as refrigerants. They cause ozone depletion as they release chloride radicals which on reacting with ozone causes its degradation.
The chlorofluorocarbons can be substituted by Hydrofluorocarbon (HFC) or Hydrochlorofluorocarbon (HCFC) for using as refrigerants and in air conditioners. Though HFCs and HCFCs also deplete ozone but to lesser extent than CFCs.
Hence, both options A and B are correct.
So, the correct answer is 'Both A and B'.