Tag: carbon cycle

Questions Related to carbon cycle

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'.

Green house effect is the cumulative result of the influences of certain gases. Identify the gas which is not involved in this influence?

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

  1. Methane

  2. Carbon dioxide

  3. Chlorofluorocarbons

  4. Nitrogen

Show answer
Correct Option: D
Explanation:

Certain gases such as methane, carbon dioxide, chlorofluorocarbons are called greenhouse gases because they absorb and thus trap some of the radiation. The nitrogen is the second most abundant act found in the atmosphere after oxygen. These gases do not have the ability to intercept infrared radiation and hence they do not contribute to causing of the greenhouse effect. Methane, carbon dioxide and chlorofluorocarbons are potent greenhouse gases.

Hence, the correct answer is 'Nitrogen'.

The two gases making highest relative contribution to the green house gases are

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

  1. $CH _4$ and $N _2O$

  2. CFCs and $N _2O$

  3. $CO _2$ and $NO _2$

  4. $CO _2$ and $CH _4$

Show answer
Correct Option: D
Explanation:
The gases responsible for green house effect are called green house gases which trap the radiations and don't let them reflect back from the earth's surface. The green house gases are Chlorofluorocarbons (CFC's), Carbon dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O). 
The approximate percentage of different greenhouse gases in the atmosphere is:
CFCs - 14%
CO2 - 60%
‎CH4 - 20%
N2O - 6%
Hence, CO2 and CH4 have highest relative contribution to green house gases.
So, the correct answer is 'CO2 and CH4'.

At present, the concentration of atmospheric $CO 2$ is ________.

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

  1. $100$ ppm

  2. $240$ ppm

  3. $380$ ppm

  4. $520$ ppm

Show answer
Correct Option: C
Explanation:
CO2 is a major pollutant of air and a green house gas that contributes to global warming. Concentration of CO2 in the atmosphere is expressed in terms of parts per million or ppm. According to latest research by forecasting systems, CO2 concentration was found to be about 380 ppm which in recent years has increased upto 400 ppm.
So, the correct answer is '380 ppm'.

Gases responsible for green house effect are

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

  1. $CO _2$

  2. CFC

  3. $N _2O$

  4. All the above

Show answer
Correct Option: D
Explanation:

A greenhouse gas is a gas in an atmosphere that absorbs and emits radiant energy within the thermal infrared range. This process is the fundamental cause of the greenhouse effect. The primary greenhouse gases in Earth's atmosphere are water vapour, carbon dioxide, methane, CFC's, nitrous oxide, and ozone.

So the correct answer is 'All the above'.

One GHG contributes $6\%$ to total global warming, other contributes to $20\%$; they are.

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

  1. $NO _2$ and $CO _2$

  2. $N _2O$ and CFCs

  3. CFCs and methane

  4. $N _2O$ and methane

  5. $CO _2$ and CFCs

Show answer
Correct Option: D
Explanation:
The relative contribution of various greenhouse gases to total global warming are as follows:
Methane: 20%
CFCs(Chloro-fluoro-carbons): 14%
N$ _2$O: 6%
Carbon dioxide: 60%
So, the correct answer is 'Option D- N$ _2$O and methane'.