Biodiversity: concept, patterns, importance, loss
- Match List I with List IIList I: A. Robert May; B. Alexander von Humboldt; C. Paul Ehrlich; D. David TilmanList II: I. Species-Area relationship; II. Long term ecosystem experiment using out door plots; III. Global species diversity at about 7 millio… Answer: 3. A-III, B-I, C-IV, D-II Key idea: link each scientist with the idea they are known for. Robert May: global species diversity about... 1
- Tropical regions show greatest level of species richness becauseA. Tropical latitudes have remained relatively undisturbed for millions of years, hence more time was available for species diversification.B. Tropical environments are more seasonal.C.… Answer: 2. A, C, D and E only Key idea: tropics have more species because they are stable, predictable and energy rich. A (long undisturbed... 1
- These are regarded as major causes of biodiversity loss:A. Over exploitationB. Co-extinctionC. MutationD. Habitat loss and fragmentationE. MigrationChoose the correct option: Answer: 1. A, B and D only Key idea: the "evil quartet" of biodiversity loss is habitat loss and fragmentation, over-exploitation, alien spe... 1
- Which of the following statements is correct? Answer: 3. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels. Key idea: Look at each stateme... 1
- 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 radiationsIn the light of the above statements, choose… Answer: 4. Statement I is correct but Statement II is incorrect. Key idea: An electrostatic precipitator removes particulate matter, not rad... 1
- The thickness of ozone in a column of air in the atmosphere is measured in terms of : Answer: 2. Dobson units Key idea: Ozone thickness in a column of air is measured in Dobson units (DU). Kilobase measures DNA length, decibel... 1
- Among 'The Evil Quartet', which one is considered the most important cause driving extinction of species? Answer: 2. Habitat loss and fragmentation Key idea: Of the four causes in the "Evil Quartet", habitat loss and fragmentation is the most imp... 1
- 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 particles.Statement II :Particulate matter (PM 2.5) can not be removed by scrubber but can be remove… Answer: 1. Statement I is incorrect but Statement II is correct Key idea: Electric charging of dust belongs to the electrostatic precipitato... 1
- The entire fleet of buses in Delhi were converted to CNG from diesel. In reference to this, which one of the following statements is false ? Answer: 3. The same diesel engine is used in CNG buses making the cost of conversion low The false statement is that the same diesel engine... 1
- Habitat loss and fragmentation, over exploitation, alien species invasion and co-extinction are causes for : Answer: 4. Biodiversity loss Habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinction are the four major... 1
- The device which can remove particulate matter present in the exhaust from a thermal power plant is : Answer: 4. Electrostatic Precipitator An electrostatic precipitator removes particulate matter from the exhaust of thermal power plants. Its... 1
- Dobson units are used to measure thickness of : Answer: 3. Ozone Dobson units measure the thickness of the ozone layer (1 DU = 0.01 mm of pure ozone at standard temperature and pressure).... 1
- Snow-blindness in Antarctic region is due to : Answer: 2. Inflammation of cornea due to high dose of UV-B radiation Snow-blindness is inflammation of the cornea caused by a high dose of U... 1
- Montreal protocol was signed in 1987 for control of : Answer: 2. Emission of ozone depleting substances The Montreal Protocol (1987) was an international treaty to control emission of ozone depl... 1
- According to Robert May, the global species diversity is about : Answer: 4. 7 million Key idea: Robert May estimated global species diversity at about 7 million. The IUCN figure of described species is abo... 1
- Which of the following regions of the globe exhibits highest species diversity ? Answer: 4. Amazon forests Key idea: The Amazon rainforest has the highest species diversity on Earth. It holds more than 40,000 plant specie... 1
- Which of the following pairs of gases is mainly responsible for green house effect ? Answer: 4. Carbon dioxide and Methane The main greenhouse gases are CO₂ , CH₄ , N₂O and CFCs. Among the options, carbon dioxide and methane... 1
- Match the items given in Column I with those in Column II and select the correct option given below :Column I | Column IIa. Eutrophication | i. UV-B radiationb. Sanitary landfill | ii. Deforestationc. Snow blindness | iii. Nutrient enrichmentd. Jhum… Answer: 2. a-iii b-iv c-i d-ii Key idea: Match each term with its meaning. Eutrophication: nutrient enrichment of water (iii). Sanitary land... 1
- World Ozone Day is celebrated on Answer: 2. 16 ^th September World Ozone Day marks the signing of the Montreal Protocol on 16 September 1987. 5 June is World Environment Day... 1
- In stratosphere, which of the following elements acts as a catalyst in degradation of ozone and release of molecular oxygen ? Answer: 3. Cl UV rays split chlorofluorocarbons and release chlorine atoms, which act as catalysts in converting ozone to molecular oxygen.... 1
- Which one of the following statements is not valid for aerosols ? Answer: 2. They cause increased agricultural productivity Aerosols are fine particles in the air. They change rainfall and monsoon patterns,... 1
- Alexander Von Humbolt described for the first time : Answer: 2. Species area relationships Key idea: Alexander von Humboldt studied plant diversity in South American forests. He found that spec... 1
- Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receiving effluents from Answer: 2. petroleum industry BOD measures the oxygen needed by microbes to break down organic matter, so it is a good index for organic was... 1
- A lake which is rich in organic waste may result in Answer: 3. mortality of fish due to lack of oxygen A lake with a lot of organic waste has a high microbial decomposition. The microbes use u... 1