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प्रश्न
How depletion of the ozone layer affect living organisms?
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उत्तर
- The thinning of the ozone layer results in an increase in the levels of UV radiation reaching the earth’s surface. In humans, increased UV radiation causes ageing of the skin, damage/injuries to skin cells and skin cancers including melanoma.
- It also causes cataracts and even permanent damage to the cornea, weakening of immune system. UV radiation also causes mutations in living organisms.
- DNA and proteins of living cells absorb the UV rays, and high energy of UV radiation breaks the chemical bonds of these molecules, thus affecting normal metabolism.
- UV radiation inhibits photosynthesis in most phytoplanktons as it penetrates through the ocean water. This affects the entire food chain in the aquatic ecosystem.
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संबंधित प्रश्न
Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage?
Name the group of chemical compounds which damages the ozone layer.
The gas A is used by most of the animals to obtain energy from food by the process of respiration. When A is acted upon by radiation X, it gets converted into another gas B which is an allotrope of A but poisonous when inhaled. B forms a kind of layer C in the upper atmosphere which absorbs radiations X coming from a source Y and prevent them from reaching the earth. Some chemicals Z released from the various devices on the earth are destroying the layer C slowly. In fact, a hole has already been formed in layer C over the area D of the earth.
(a) What are gases (i) A, and (ii) B? Write their molecular formulae.
(b) Name the layer C.
(c) What are (i) X, (ii) Y, and (iii) Z?
(d) Name the area D.
(e) Name any two human ailments which may be caused by X.
Give scientific reasons:
Ozone present in the stratosphere is called as “good ozone”.
How are CFCs harmful?
Match the items in column I with the closely related ones in column II.
| Column I | Column II | ||
| (i) | Chlorofluorocarbons (CFCs) | (a) | Global warming |
| (ii) | Fly ash | (b) | Biodegradable |
| (iii) | Cow dung | (c) | Nuclear radiation pollutant |
| (iv) | CO2 and methane | (d) | Acid rain |
| (v) | Sulphur dioxide | (e) | Industrial waste |
| (vi) | Iodine-131 | (f) | Ozone depletion |
The following picture depicts a certain phenomenon
- Name the phenomenon and explain it.
- Enlist the sources that are responsible for the above mentioned phenomenon.
- List out the effects of the above phenomenon on humans.
‘There is a hole in the ozone layer’. What do you understand by this?
Acid rain is caused by the oxides of ______.
______ was signed in 1987 to control emission of ozone depleting substances.
