Tag: global environmental change

Questions Related to global environmental change

The Hydrochlorofluorocarbons (HCFCs) are the compounds which have the following molecules:HydrogenCarbonChlorineFluorineWhich among the above plays the most important role in Ozone depletion?

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Hydrogen

  2. Carbon

  3. Chlorine

  4. Flourine

Show answer
Correct Option: C

Which among the following are the consequences of ozone depletion?

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Entry of UV-rays in earth's atmosphere

  2. Various skin troubles like skin cancer

  3. Cataract

  4. All of the above

Show answer
Correct Option: D
Explanation:

Ozone depletion in the stratosphere has resulted in formation of a large area of thinned ozone layer, commonly called as the ozone hole. UV radiation of wavelengths shorter than UV-B, are almost completely absorbed by Earth's atmosphere, given that the ozone layer is intact. But, UV-B damages DNA and mutation may occur. It causes aging of skin, damage to skin cells and various types of skin cancers. In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called as snow-blindness, cataract, etc. Such exposure may permanently damage the cornea. Thus, the correct answer is option D.

Ozone-layer is getting depleted because of

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Excessive use of automobiles

  2. Excessive formation of industrial units

  3. Excessive use of man made compounds containing both fluorine and chlorine

  4. Excessive deforestation.

Show answer
Correct Option: C
Explanation:

Ozone layer is a region of concentration of ozone molecule. $O _3 (O _2+ O)$ in the earth's atmosphere. The layer lies in the stratosphere at an altitude of 18-50 kms. The ozone layer naturally Shields earth's life from the harmful effect of the Sun's ultraviolet radiations.

Ozone hole enhances

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. UV radiations reaching earth

  2. Number of cataracts

  3. Skin cancers

  4. All of the above

Show answer
Correct Option: D
Explanation:
The ozone layer is mainly found in the stratosphere. Ozone layer acts as a shield that absorbs ultraviolet radiation from the sun. Due to ozone depletion by the presence of CFC gas the UV rays reaching the earth and causing harmful effects. UV rays are highly injurious to living organisms since DNA and proteins of living organisms preferentially absorb UV rays and its high energy breaks the chemical bonds within these molecules. UV-B damages DNA and mutation may occur. It causes aging of the skin, damage to skin cells and various types of skin cancers. In the human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of the cornea, called as snow-blindness, cataract, etc. Such exposure may permanently damage the cornea. Therefore, the correct answer is option D.

In the environment, ozone is known for its 

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Harmful effects

  2. Useful effects

  3. Both A and B

  4. Inert nature

Show answer
Correct Option: C
Explanation:

Ozone is an inorganic molecule. It is a pale blue gas with a distinctively pungent smell. In the environment ozone is known for its both harmful and useful effects.
Ozone present in stratosphere is useful as it act like shield and protect the earth from harmful UV-rays which can cause serious problems like skin cancer and decrease in level of photosynthesis. Ozone present in troposphere act as pollutant and have many deleterious effects. 

Therefore, the correct answer is option C.

Ozone depletion shall cause higher incidence of

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Skin cancers

  2. Cataract

  3. Decreased immunity

  4. All of the above

Show answer
Correct Option: D
Explanation:

Ozone depletion causes the harmful UV-B radiations to strike the earth surface. These radiations are capable of causing various health issues like malignant skin cancers, cataract, decreased immunity, decreased primary productivity, chlorophyll bleaching etc. 

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

CFCs split up in stratosphere to release chlorine by the action of

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. UV - A

  2. UV - B

  3. UV - C

  4. All of the above

Show answer
Correct Option: C
Explanation:

The UV-C radiations breakdown the bonds in the chlorofluorocarbons (CFCs) to release the chlorine monoxide and the nascent chlorine. These further react with the ozone to split it into ordinary oxygen molecules. The oxygen molecules are further broken down into nascent oxygen, which acts as the radicle. 

Hence, the correct answer is 'UV-C'.

Part of ozone is destroyed over poles during

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Polar spring

  2. Winter

  3. Summer

  4. Period of snow fall

Show answer
Correct Option: A
Explanation:

Polar spring, also known as the Antarctic Spring is the period from late August to early October and the strong westerlies circulate around the Antarctic continent creating a polar vortex. The polar vortex results in the formation of the polar stratospheric clouds which trap most of the gases including the ozone-depleting factors like CFCs, methyl bromide etc. 

Hence, the correct answer is 'Polar Spring'.

Ultraviolet radiations from sunlight cause a reaction which produces

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. $O _3$

  2. $SO _2$

  3. CO

  4. $CH _4$

Show answer
Correct Option: A
Explanation:

In the stratosphere of the atmosphere, the UV rays are concentrated and these react with the oxygen to produce the ozone. This ozone persists in the form of the ozone layer and acts as the absorbent for the UV rays. Ozone layer does not allow the UV-B and UV-C from hitting the earth's surface, thereby preventing the various harmful after effects. Sulphur dioxide, carbon monoxide and methane are the primary pollutants of air.

Hence, the correct answer is 'O$ _{3}$'.

In coming years, skin related disorders will become more common due to ________.

commercial applications global environmental change causes of resource depletion causes of greenhouse effect ozone layer depletion

  1. Excessive use of detergents

  2. Water pollution

  3. Air pollution

  4. Depletion of ozone layer

Show answer
Correct Option: D
Explanation:

The ever increase in the use of ozone-depleting substances like CFCs, HFCs, methyl bromide etc. will continue destroying the ozone layer in the stratosphere. The depletion of the ozone layer will result in the penetration of more UV-A and UV-B radiations to the earth surface. These radiations are strong mutagens as they distort the structure of the skin cell DNA when the skin is exposed to the UV rays. It results in skin related disorders like pigmentation, skin cancer etc. 

Hence, the correct answer is 'Depeletion of the ozone layer'.