Tag: zoology

Questions Related to zoology

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'.

Greenhouse gases are

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

  1. $CO _2$ and $CH _4$

  2. $N _2O$ and CFCs

  3. Ozone

  4. All of the above

Show answer
Correct Option: D
Explanation:

Carbon dioxide and methane are naturally occurring gases. Nitrous oxides are formed due to denitrification and combustion of the fossil fuels. CFCs are used as refrigerants and propellants. Ozone is formed as a secondary pollutant. All these are greenhouse gases because they show greenhouse effect by absorbing the the long-wavelength infra-red radiations coming from the earth's surface and preventing from leaving the atmosphere. This effect is responsible for maintaining the ambient temperature on the earth. Their  amounts have increased over the past years and this has adversely affected the global temperature by raiding it. This is called global warming and is responsible for climate change. 

Hence, the correct answer is 'All of the above'

Which one of the following statements is not correct?

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

  1. The greenhouse gases trap out the heal in infra-red radiation

  2. Natural gas supplies five percent f global energy needs

  3. One molecule of CFC can trap as many as $10,000$ molecules of $CO _2$

  4. The atmospheric life time to $CFCl _3$ is estimated at $75$ years

Show answer
Correct Option: A

Green house gases are called as such because they.

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

  1. Prevent the escape of heat waves reradiated from the earth's surface

  2. Are produced in greenhouses

  3. Are used in warming plant growth chambers

  4. Help in maintaining atmospheric $O _2$ and $CO _2$ balance

Show answer
Correct Option: A

Choose the correct answer form the alternatives given.
The second biggest greenhouse gas emitter (after the USA) in the world is:

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

  1. Russia

  2. Germany

  3. China

  4. Japan

Show answer
Correct Option: C

Cyclic variations of CO2CO2 concentration in the atmosphere are due to changes in

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

  1. photosynthetic activity

  2. respiratory activity

  3. burning of fossil fuels

  4. action of infra-red rays

Show answer
Correct Option: C
Explanation:

The burning of fossil fuels such as gasoline, coal, oil, natural gas in combustion reactions results in the production of carbon dioxide. There are cyclic variations of Carbon dioxide concentration in the atmosphere due to this reason. 

So, the correct optionos 'Burning of fossil fuels'.

Which one of the following is major given house gas?

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

  1. Freon

  2. $CO _2$

  3. CFC

  4. $NO _2$

Show answer
Correct Option: B
Explanation:

greenhouse gases are those gases which absorb the heat or thermal infrared radiations of the sun and is responsible for an increase in the temperature of the earth's surface .there are several greenhouse gases that are produced either naturally or is being emitted in the atmosphere by a man-made source. The most abundant or major greenhouse gas is Carbon Dioxide.

so the correct answer is 'CO2'.