Environment and Ecology questions with answers

2,222 multiple-choice questions. Open any question for its answer and explanation.

Questions asked in State PSC and UPSC prelims, by topic. Each topic also has notes to read.

Read the notes: Ecology →

26. Which one of the following is correctly matched?Asked in UPPCS Prelims 2024
27. Example of Lotic ecosystem is -Asked in UPPCS Prelims 2023
28. Ecotone is aAsked in UPSC CISF AC EXE 2024
29. As an ecosystem, wetlands arc useful for which of the following ?Asked in UPPCS Prelims 2012
30. Which of the following is an artificial ecosystem?Asked in UPPCS Prelims 2016
31. The following ecosystem develops in flowing water:Asked in WBCS Main Paper 4 2023
32. What is Plankton?Asked in WBCS Main Paper 4 2019
33. Which term is used to denote an excess of nutrition in a lake or a water body caused by the deposit of run-off nutrients from land?Asked in COMPUTER PROGRAMMER 2019
34. Which of the following statements is correct to explain a 'lenthic' ecosystem?Asked in GK CDPO 33 2023 2709 2024
35. In the nighttime, it is advised not to sleep under trees becauseAsked in BPSC Prelims Exam 67th Cancelled
36. Dolomite powder is applied in some agricultural lands. The purpose of applying it is toAsked in UPSC CDS 2 2016
37. Which is not gaseous cycle ?Asked in CGPSC Prelims Exam 2014
38. Nitrogen cycle is one of the most important microorganisms-mediated chemical reactions in aquatic and soil environments. In this context consider the following statements : 1. Nitrogen fixation is the process of oxidising NH₃ to NO₃⁻. 2. Nitrification process causes reduction of NO₃ and NO₂⁻ to NO₂, followed by recycling of N₂ to the atmosphere. 3. Denitrification converts molecular N₂ into a fixed form as an organic nitrogen. How many of the statements given above is/are correct ?Asked in UPSC Geoscientist 2024
39. The natural cycle that circulates elements between the earth and the environment (particularly between living and non-living matter) is calledAsked in GPSC Prelims CSP 2 2017
40. In which form is phosphorus predominantly found in soil ?Asked in HPPSC HPAS Prelims 2010
41. Which of the following processes does not occur in the water cycle ?Asked in HPPSC HPAS Prelims 2018
42. Movement of nutrients in the eco-system is alwaysAsked in KPSC KAS Prelims 2014
43. Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R). Select your answer from the following options. Assertion (A): Deforestation results in the increase of concentration of carbon dioxide in the atmosphere. Reason (R): Forests utilise carbon dioxide during the process of photosynthesis for manufacturing of food.Asked in MPSC CS Prelims 2019
44. The role of bacteria in an ecosystem is to :Asked in OPSC CS Prelims 2015
45. Which of the following organisms fix nitrogen in aquatic ecosystems ?Asked in OPSC CS Prelims 2016
46. With reference in the Deep Carbon Observatory (DCO) which of the following statements is/are correct? 1. It is Global Research Programme to outreach role of carbon on earth. 2. It conducts field observations of deep microbial ecosystem. Select the correct answer using the codes given belowAsked in UPPCS Prelims 2019
47. The movement of nutrient elements through the various components of an ecosystem is calledAsked in UPPCS Prelims 2020
48. Which one of the following does not increase the amount of car bon-dioxide in carbon cycle on earth?Asked in UPPSC Upper Mains 2012
49. Biogeochemical cycle in which the main reservoir is not the soilAsked in APPSC Group II Mains paper 2 2025
50. The following is a sedentary cycle:Asked in WBCS Main Paper 4 2019