General Knowledge - Biology - Discussion

Discussion :: Biology - Section 1 (Q.No.2)


Ozone hole refers to

[A]. hole in ozone layer
[B]. decrease in the ozone layer in troposphere
[C]. decrease in thickness of ozone layer in stratosphere
[D]. increase in the thickness of ozone layer in troposphere

Answer: Option C


No answer description available for this question.

Parul said: (Jan 2, 2011)  
Due to which climate change is happening (as harmful you. We rays from the sun is getting way to reach the earth as its thickness is decreasing) results in global warming.

Anil, said: (Mar 28, 2011)  
As pollution increase all the chlorofloro carbons comes from our earth then ozone layer thickness is decrease as a result UV rays of sun directly comes on earth and causes us to cancer .

Anuja Singh said: (Sep 20, 2011)  
As global warming is increasing and people are cutting trees for their greed due to that global warming is increasing and amount of pollution is increasing in the enviorment thats the reason why we all are facing these problems occuring in our enviorment.

Sai said: (Oct 1, 2011)  
Due to deplenishing of ozone layer harmful uv rays reach the surface and results in causing cancer. Both cloroflurohydro carbons and methane gas are responsible for that.

Deepak said: (Nov 22, 2011)  
1. CL + O3 - CLO + O2
2. CL + CLO - CL2+O

Vijaya said: (Apr 12, 2012)  
We know that stratosphere is rich in ozone gas. That's why ozone hole means decreasing of ozone layer in stratosphere.

Don said: (May 17, 2012)  
Nothing else only we greedy humans are d cause of global warming.

Praveen said: (Jul 18, 2012)  
Stratosphere mainly consists of ozone gas as the thickness of ozone is reduced mainly because of CFC CO2 CH4 etc.,

Priya said: (Dec 10, 2012)  
Ozone layer is present at the end of stratosphere.

Harsh Kant said: (Jun 5, 2013)  
As the result main cause of decreases in ozone layer is increases in pollution that's by UV rays enter in earth and causes infections, cancer and other diseases.

Amrutha said: (Jun 14, 2013)  
It is not good to have a hole in ozone layer. The main cause is increase of pollution.

Sheetal said: (Nov 1, 2013)  
Main cause for this is the pollution in our environment. And it allows the harmful UV rays to enter our air. And it is near the stratosphere.

B.Jayasree said: (Dec 23, 2013)  
Ozone is in stratosphere but due to the chlorofluorocarbons ozone is depletion and decreasing this thickness.

Bhavani said: (Dec 26, 2013)  
It is decreasing the thickness off ozone layer due to which UV rays fall on us.

Awais said: (Jan 10, 2014)  
Stratosphere is also known as ozonosphere O3 and it absorb the cosmic and uv rays coming from sun and causes skin cancer.

Abdul Aziz said: (Jan 15, 2014)  
It is due to fluorochlorocarbons which reduce the ozone layer.

Nirudhi said: (Mar 2, 2014)  
We know that stratosphere is rich in ozone gas. That's why ozone hole means decreasing of ozone layer in stratosphere.

Akshaya said: (Mar 30, 2014)  
Because stratosphere is present nearer to the sun. Due to this it affects the ozone layer.

Mithun said: (Apr 11, 2014)  
Ozone layer filters the UV rays from the sun which causes skin cancer. Because of pollution the ozone layer is depleting. If it completely depletes OZONE we would be in DANGER ZONE.

Deepthi said: (May 25, 2014)  
Because of the green houses gases our ozone layer is depleting already we're going to be in danger zone so its all our responsibility to protect our ozone layer.

Momina Abbas said: (Jun 6, 2014)  
Stratosphere is filled with ozone gas which filters the UV rays coming from sun. So the ozone hole is the decrease of thickness of ozone in the stratosphere due to pollution.

Dhruvil said: (Jun 20, 2014)  
Ozone hole refers to a hole in ozone layer which is present in stratosphere and responsible for the absorption of ultraviolet radiations.

Hole in ozone layer is produced due to large amount of pollutants in air such as Co2, Co, So2, So3 gases present in the air.

Bilal Khan said: (Aug 6, 2014)  
Ozone hole refer to hole which is present in stratosphere and ozone layer depleting day by day.

Snehil Kumar said: (Sep 11, 2014)  
Due to chlorofluorocarbon decrease in thickness of ozone layer.

Abhishek said: (Sep 19, 2014)  
As the pollution increases the harmful chlorofluorocarbon goes to the ozone layer and breaks into small atoms which makes the ozone layer thinner.

Abhishek said: (Nov 14, 2014)  
If we say ozone hole it means decrease in ozone layer because hole is forms when there is no or low amount of ozone gas.

Shanmukha Srinivas said: (Mar 3, 2015)  
Actually stratosphere is about 18km high from earth. Mostly fridges, aerosol sprays, deforestation supports the thinning of O3.

Harish said: (Mar 30, 2015)  
Ozone hole means decrease thickness of ozone layer.

Haifa Hassan said: (Jun 17, 2015)  
Ozone hole means decrease in thickness of the ozone layer as a result of green house effect producing green house gases such as chlorofluorocarbon.

Sameera said: (Jul 23, 2015)  
This is due to human being only.

Sameera said: (Jul 23, 2015)  
Yes ozone hole decrease the thickness of ozone layer as the result global warming can occur.

Amrit Singh said: (Sep 24, 2015)  
Stop global warming to protect our ozone layer and protect ourselves from harmful uv rays of sun.

Amitkumar said: (Dec 21, 2015)  
I think the responsible facts of global warming are chlorofluorocarbon, methane and carbon di oxide. Due to heavy pollution the environment of our Earth is is being polluted. Day by day the ozone layer is decreasing. So we can facing the ultraviolet rays of sun that is very harmful for us and it causes cancer.

Kartheek said: (Dec 29, 2015)  
Where ozone layer damaged places in India and effects of radiation?

Vikas Kalyan Sutar said: (Mar 6, 2016)  
I think the main cause of ozone layer deflection is the reaction of ozone layer with CFC which decrease the thickness of ozone layer and allow UV to pass through it.

Pradeep said: (Apr 16, 2016)  
Ozone hole refers to decrease in thickness of Ozone layer in Stratosphere.

As pollution (Co2, Co, So2, So3 gases present in the air) increases and all the chlorofloro carbons comes from earth then ozone layer thickness decreases, as a result. Ultra Violate rays of the sun directly come on earth and causes us to cance.

Kamlendra Singh said: (Jun 28, 2016)  
Temperature increased day by day is called global warming. In lase decade. 2 degree increased.

Moses said: (Sep 2, 2016)  
The ozone layer is depleting due to the chlorofluorocarbon thereby causing the ultraviolet rays to shun on.

Ilobun Faithful said: (Sep 9, 2016)  
The ozone hole is a result of the separation of ozone. When they separate, holes are made.

Faisal Mirza said: (Oct 9, 2016)  
Temperature is increased day by day due to hole in ozone layer the hole in ozone layer due to direct UV rayes from the sun.

Faisal Mirza said: (Oct 9, 2016)  
There are many reasons to increasing temperature. But main reasons is increasing pollution in our environment and also increased temperature by direct UV rayes comes on earth from the Sun.

Sanjay said: (Feb 5, 2017)  
In which region on earth already UV radiations causes cancer due to ozone layer depletion?

Sunitha said: (Feb 10, 2017)  
Causes the pollutions then decrease the thickness of ozone layer.

Ranjana Bhardwaj said: (Mar 5, 2017)  
Causes the pollution then decrease the thickness of ozon layer.

Msrinivasrao said: (May 13, 2017)  
If we take an example of a filter, if we don't take care of it and make it dirty. And if we don't clean it, it tends to be dirty and filter spoils. Same like this ozone layer also will spoil like a filter because of pollution made by humans.

Shaz said: (Aug 14, 2017)  
Ozone layer is the layer that blocks the altra violet rays.

Akshika said: (Aug 23, 2017)  
Due to pollutants in atmosphere ozone layer get thin or may be damage.

Bugli said: (Sep 11, 2017)  
For the first time, the ozone hole was seen in Antartica which is completely free of pollution. What is the reason behind it?

Mukesh Kumar said: (Jan 6, 2018)  
Due to pollutants in the atmosphere, ozone layer get thin or may be damaged.

Gideon said: (May 28, 2018)  
It is Due to increasing levels of global warming, greenhouse effect Eg; the use of CFCs such pollutants affect the ozone layer.

Khadijah said: (Jun 2, 2018)  
It is Mainly caused by pollution of the environment harmful gases Eg; carbon4oxide act as a blanket preventing uv rays.

Vinay said: (Jul 4, 2018)  
It is caused by the pollution and released harmful gases into the atmosphere like carbon monoxide, nitrogen, carbon dioxide, sulphur oxide, etc.

Bks said: (Oct 24, 2019)  
The different layers of the atmosphere

The atmosphere can be divided into layers based on its temperature, as shown in the figure below. These layers are the troposphere, the stratosphere, the mesosphere and the thermosphere. A further region, beginning about 500 km above the Earth's surface, is called the exosphere.

The red line on the figure below shows how temperature varies with height (the temperature scale is given along the bottom of the diagram). The scale on the right shows the pressure. For example, at a height of 50 km, the pressure is only about one thousandth of the pressure at the ground.

The Troposphere

This is the lowest part of the atmosphere - the part we live in. It contains most of our weather - clouds, rain, snow. In this part of the atmosphere the temperature gets colder as the distance above the earth increases, by about 6.5°C per kilometre. The actual change of temperature with height varies from day to day, depending on the weather.

The troposphere contains about 75% of all of the air in the atmosphere, and almost all of the water vapour (which forms clouds and rain). The decrease in temperature with height is a result of the decreasing pressure. If a parcel of air moves upwards it expands (because of the lower pressure). When air expands it cools. So air higher up is cooler than air lower down.

The lowest part of the troposphere is called the boundary layer. This is where the air motion is determined by the properties of the Earth's surface. Turbulence is generated as the wind blows over the Earth's surface, and by thermals rising from the land as it is heated by the sun. This turbulence redistributes heat and moisture within the boundary layer, as well as pollutants and other constituents of the atmosphere.

The top of the troposphere is called the tropopause. This is lowest at the poles, where it is about 7 - 10 km above the Earth's surface. It is highest (about 17 - 18 km) near the equator.

The Stratosphere

This extends upwards from the tropopause to about 50 km. It contains much of the ozone in the atmosphere. The increase in temperature with height occurs because of absorption of ultraviolet (UV) radiation from the sun by this ozone. Temperatures in the stratosphere are highest over the summer pole, and lowest over the winter pole.

By absorbing dangerous UV radiation, the ozone in the stratosphere protects us from skin cancer and other health damage. However chemicals (called CFCs or freons, and halons) which were once used in refrigerators, spray cans and fire extinguishers have reduced the amount of ozone in the stratosphere, particularly at polar latitudes, leading to the so-called "Antarctic ozone hole".

Now humans have stopped making most of the harmful CFCs we expect the ozone hole will eventually recover over the 21st century, but this is a slow process.

The Mesosphere

The region above the stratosphere is called the mesosphere. Here the temperature again decreases with height, reaching a minimum of about -90°C at the "mesopause".

The Thermosphere and Ionosphere

The thermosphere lies above the mesopause, and is a region in which temperatures again increase with height. This temperature increase is caused by the absorption of energetic ultraviolet and X-Ray radiation from the sun.

The region of the atmosphere above about 80 km is also caused the "ionosphere", since the energetic solar radiation knocks electrons off molecules and atoms, turning them into "ions" with a positive charge. The temperature of the thermosphere varies between night and day and between the seasons, as do the numbers of ions and electrons which are present. The ionosphere reflects and absorbs radio waves, allowing us to receive shortwave radio broadcasts in New Zealand from other parts of the world.

The Exosphere

The region above about 500 km is called the exosphere. It contains mainly oxygen and hydrogen atoms, but there are so few of them that they rarely collide - they follow "ballistic" trajectories under the influence of gravity, and some of them escape right out into space.

The Magnetosphere

The earth behaves like a huge magnet. It traps electrons (negative charge) and protons (positive), concentrating them in two bands about 3,000 and 16,000 km above the globe - the Van Allen "radiation" belts. This outer region surrounding the earth, where charged particles spiral along the magnetic field lines, is called the magnetosphere.

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