The thickness of ozone in a column of air in the atmosphere is measured in terms of

The ozone layer plays a vital role in making the planet habitable for us and other species. High in the atmosphere – between 10 to 50 kilometers above the earth’s surface – the ozone layer absorbs most of the sun’s ultraviolet radiation. But, during the 1970s, ‘80s, and ‘90s, humans were emitting large quantities of substances that depleted the ozone layer. This led to the creation of ozone holes at the earth’s poles, exposing life to higher levels of ultraviolet radiation and increasing the risks of skin cancer in humans. During the 1980s, the world came together to form an international agreement to reduce – and eventually eliminate – emissions of these depleting substances. The political agreements were very effective. Since then, global emissions have fallen by more than 99%. The ozone holes have stopped growing and are now starting to close. This page includes all of our data, visualizations, and writing on the ozone layer, its depletion, and its path to recovery. Emissions of substances that deplete the ozone layer have fallen by more than 99% In 1987, the world signed the Montreal Protocol: the first global agreement to reduce the use of substances that deplete the ozone layer, known as ‘ozone-depleting substances.’ These are substances such as chlorofluorocarbons (CFCs); hydrochlorofluorocarbons (HFCs); and halon gases used in refrigerators, deodorants, and other industrial processes. Since this agreement entered into force in 1989, global emissions of ozone-deplet...

The thickness of ozone in a column of air in the atmosphere is measured in terms of : 1. Kilobase 2. Dobson unit 3. Decibels 4. Decameter Environmental Issues Botany NEET Practice Questions, MCQs, Past Year Questions (PYQs), NCERT Questions, Question Bank, Class 11 and Class 12 Questions, and PDF solved with answers What will happen if fresh water lake gets contaminated by addition of polluted water with high BOD? 1. Amount of dissolved oxygen in the lake will decrease. 2. The lake will remain unaffected 3. Number of submerged aquatic plants in the lake will increase 4. Number of aquatic animals in the lake will increase. Match List - I with List - II List-I List-II (A) Deforestation (I) Responsible for heating of Earth's surface and atmosphere (B) Reforesation (II) Conversion of forested areas to non-forested areas (C) Green-house effect (III) Natural ageing of lake by nutrient enrichment of its water (D) Eutrophication (IV) Process of restoring a forest that once existed but was removed Choose the correct answer from the options given below: 1. (A) - (IV), (B) - (III), (C) - (II), (D) - (I) 2.(A) - (I), (B) - (II), (C) - (III), (D) - (IV) 3.(A) - (III), (B) - (I), (C) - (II), (D) - (IV) 4.(A) - (II), (B) - (IV), (C) - (I), (D) - (III) Select the correct statements regarding dissolved Oxygen and Biochemical Oxygen demand. (A) BOD is inversely related to dissolved oxygen (B) Low dissolved oxygen and high BOD lead to loss of aquatic life. (C) High BOD leads to high dissolve...

The thickness of ozone in a column of air in the atmosphere is measured in terms of : 1. Kilobase 2. Dobson unit 3. Decibels 4. Decameter Past Year (2019 onward - NTA Papers) MCQs Environmental Issues Botany NEET Practice Questions, MCQs, Past Year Questions (PYQs), NCERT Questions, Question Bank, Class 11 and Class 12 Questions, and PDF solved with answers Which one of the following statements is NOT correct? 1. The amount of some toxic substances of industrial waste water increases in the organisms at successive trophic levels. 2. The micro-organisms involved in biodegradation of organic matter in a sewage polluted water body consume a aquatic organisms. 3. Algal blooms caused by excess of organic and promote fisheries. 4. Water hyacinth grows abundantly in eutrophic water bodies and leads to an imbalance in the ecosystem dynamics of the water body. Given below are two statements: Statement I: Electrostatic precipitator is most widely used in thermal power plant. Statement II: Electrostatic precipitator in thermal power plant removes ionising radiations In the light of the above statements, choose· the most appropriate answer from the options given below: Which of the following statements is correct? 1. Algal Bloom decreases fish mortality 2. Eutrophication refers to increase in domestic sewage and waste water in lakes. 3. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels. 4. Presence of large amount of nutrients in water r...

The ozone layer plays a vital role in making the planet habitable for us and other species. High in the atmosphere – between 10 to 50 kilometers above the earth’s surface – the ozone layer absorbs most of the sun’s ultraviolet radiation. But, during the 1970s, ‘80s, and ‘90s, humans were emitting large quantities of substances that depleted the ozone layer. This led to the creation of ozone holes at the earth’s poles, exposing life to higher levels of ultraviolet radiation and increasing the risks of skin cancer in humans. During the 1980s, the world came together to form an international agreement to reduce – and eventually eliminate – emissions of these depleting substances. The political agreements were very effective. Since then, global emissions have fallen by more than 99%. The ozone holes have stopped growing and are now starting to close. This page includes all of our data, visualizations, and writing on the ozone layer, its depletion, and its path to recovery. Emissions of substances that deplete the ozone layer have fallen by more than 99% In 1987, the world signed the Montreal Protocol: the first global agreement to reduce the use of substances that deplete the ozone layer, known as ‘ozone-depleting substances.’ These are substances such as chlorofluorocarbons (CFCs); hydrochlorofluorocarbons (HFCs); and halon gases used in refrigerators, deodorants, and other industrial processes. Since this agreement entered into force in 1989, global emissions of ozone-deplet...

The thickness of ozone in a column of air in the atmosphere is measured in terms of : 1. Kilobase 2. Dobson unit 3. Decibels 4. Decameter Past Year (2019 onward - NTA Papers) MCQs Environmental Issues Botany NEET Practice Questions, MCQs, Past Year Questions (PYQs), NCERT Questions, Question Bank, Class 11 and Class 12 Questions, and PDF solved with answers Why CNG is considered better fuel than diesel? a. It cannot be adulterated b. It takes less time to fill the fuel tank c. It burns more efficiently d. It is cheaper e. It is less inflammable. Choose the most appropriate answer from the options given below 1. (a), (b), (c), (e) only 2. (a), (c), (d) only 3. (a), (b), (d), (e) only 4. (c), (d), (e) only Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R) Assertion (A) : Spirulina is a microbe that can be used for reducing environmental pollution. Reason (R) : Spirulina is a rich source of protein, carbohydrates, fats, minerals and vitamins. In the light of the above statements, choose the most appropriate answer from the options given below: 1. Both (A) and (R) are correct and (R) is the correct explanation of (A) 2. Both (A) and (R) are correct but (R) is not the correct explanation of (A) 3. (A) is correct but (R) is not correct 4. (A) is not correct but (R) is correct Given below are two statements: Statement I: In a scrubber the exhaust from the thermal plant is passed through the electric wires to charge the dust p...

The thickness of ozone in a column of air in the atmosphere is measured in terms of : 1. Kilobase 2. Dobson unit 3. Decibels 4. Decameter Environmental Issues Botany NEET Practice Questions, MCQs, Past Year Questions (PYQs), NCERT Questions, Question Bank, Class 11 and Class 12 Questions, and PDF solved with answers Which one of the following statements is NOT correct? 1. The amount of some toxic substances of industrial waste water increases in the organisms at successive trophic levels. 2. The micro-organisms involved in biodegradation of organic matter in a sewage polluted water body consume a aquatic organisms. 3. Algal blooms caused by excess of organic and promote fisheries. 4. Water hyacinth grows abundantly in eutrophic water bodies and leads to an imbalance in the ecosystem dynamics of the water body. Given below are two statements: Statement I: Electrostatic precipitator is most widely used in thermal power plant. Statement II: Electrostatic precipitator in thermal power plant removes ionising radiations In the light of the above statements, choose· the most appropriate answer from the options given below: Which of the following statements is correct? 1. Algal Bloom decreases fish mortality 2. Eutrophication refers to increase in domestic sewage and waste water in lakes. 3. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels. 4. Presence of large amount of nutrients in water restricts 'Algal Bloom' What will happen if...