Questions on Environment and Ecology (Part 3)

In the 2025 Prelims, there were 20 questions on the subject Environment and Ecology. Here are Questions 11-20.

Question 11

11. With reference to the planet Earth, consider the following statements: 

1. Rain forests produce more oxygen than that produced by oceans.  

2. Marine phytoplankton and photo synthetic bacteria produce about 50% of the world's oxygen.  

3. Well-oxygenated surface water contains several folds higher oxygen than that in atmospheric air.  

Which of the statements given above is/are correct?  

(a) 1 and 2 only

(b) 2 only  

(c) 1 and 3 only

(d) None of the above statements is correct.

Question 12

12. Consider the following statements:  

1. India has joined the Minerals Security Partnership as a member. 

2. India is a resource-rich country in all the 30 critical minerals that it has identified. 

3. The Parliament in 2023 has amended the Mines and Minerals (Development and Regulation) Act, 1957 empowering the Central Government to exclusively auction mining lease and composite license for certain critical minerals.  

Which of the statements given above are correct?  

(a) 1 and 2 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1,2, and 3

 Question 13

13. Consider the following statements: 

Statement I: Circular economy reduces the emissions of greenhouse gases.  

Statement II: Circular economy reduces the use of raw materials as inputs.  

Statement III: Circular economy reduces wastage in the production process.  

Which one of the following is correct in respect of the above statements?  

(a) Both Statement II and Statement III are correct and both of them explain Statement I.  

(b) Both Statement II and Statement III are correct but only one of them explains Statement I.  

(c) Only one of the Statements II and III is correct and that explains Statement I.  

(d) Neither Statement II nor Statement III is correct. 

 Question 14

14. Consider the following statements:

1. Without the atmosphere, temperature would be well below freezing point everywhere on the Earth's surface. 

2. Heat absorbed and trapped by the atmosphere maintains our planet's average temperature. 

3. Atmosphere's gases, like carbon dioxide, are particularly good at absorbing and trapping radiation. 

Which of the statements given above are correct?  

(a) 1 and 3 only  

(b) 1 and 2 only  

(c) 1,2, and 3

(d) 2 and 3 only

 Question 15

15. Artificial way of causing rainfall to reduce air pollution makes use of

(a) Silver iodide and potassium iodide  
(b) Silver nitrate and potassium iodide  
(c) Silver iodide and potassium nitrate  
(d) Silver nitrate and potassium chloride 

 Question 16

16. Which organization has enacted the Nature Restoration Law (NRL) to tackle climate change and biodiversity loss?  

(a) The European Union  
(b) The World Bank  
(c) The Organization of Economic Cooperation and Development 
(d) FAO  

 Question 17

17. Consider the following statements:  

Statement I: Of the two major ethanol producers in the world, i.e., Brazil and the United States of America, the former produces more ethanol than the latter.  

Statement II: Unlike in the United States of America where corn is the principal feedstock for ethanol production, sugarcane is the principal feedstock for ethanol production in Brazil  

Which one of the following is correct in respect of the above statements?   

(a) Both Statement I and Statement II are correct, and Statement II explains Statement I.   

(b) Both Statement I and Statement II are correct, but Statement II does not explain Statement I.   

(c) Statement I is correct, but Statement II is not correct.   

(d) Statement I is not correct, but Statement II is correct.

 Question 18

18. The World Bank warned that India could become one of the first places where wet-bulb temperatures routinely exceed 35 °C. Which of the following statements best reflect(s) the implication of the above-said report?  

1. Peninsular India will most likely suffer from flooding, tropical cyclones and droughts. 

2. The survival of animals including humans will be affected as shedding of their body heat through perspiration becomes difficult.  

Select the correct answer using the code given below.   

(a) 1 only   

(b) 2 only   

(c) Both 1 and 2 

(d) Neither 1 nor 2

 Question 19

19. Consider the following statements about PM Surya Ghar Muft Bijli Yojana: 

1. It targets installation of one crore solar rooftop panels in the residential sector.  

2. The Ministry of New and Renewable Energy aims to impart training on installation, operation, maintenance and repairs of solar_rooftop systems at grassroot levels. 

3. It aims to create more than three lakhs skilled manpower through fresh skilling, and upskilling, under scheme component of capacity building.   

Which of the statements given above are correct?   

(a) 1 and 2 only   

(b) 1 and 3 only   

(c) 2 and 3 only   

(d) 1, 2, and 3

 Question 20

20. Consider the following activities:   

1. Production of crude oil 

2. Refining, storage, and distribution of petroleum 

3. Marketing and sale of petroleum products 

4. Production of natural gas 

How many of the above activities are regulated by the Petroleum and Natural Gas Regulatory Board (PNGRB) in India? 

(a) Only one 

(b) Only two 

(c) Only three 

(d) All four  

(Note: See the next post for the correct answers, explanations, and background information.)

Questions 1-10 were covered in the previous two posts.

The Fifth Edition of my book is just out:

Rajagopalan, R., Environment and Ecology with Disaster Management: A Complete Guide for the Civil Services Preliminary and Main Examinations, Gurugram:  OakBridge Publishing, 2025.

You can order the book here.

You can also boost your preparation for the Mains with my Q&A book:

Rajagopalan, R., Rapid Revision Series (with solved PYQs, Practice Questions and Answers): Environment, Ecology and Disaster Management for UPSC, IFS and State Civil Services Main Exams, Gurugram:  OakBridge Publishing, 2024.

You can order the book here.