Prelims Questions: Plant Communities & Major Vegetation | Environment for UPSC CSE PDF Download

Q1: Artificial way of causing rainfall to reduce air pollution makes use of   (2025)
(a) silver iodide and potassium iodide
(b) silver nitrate and potassium iodide
(c) silver iodide and potassium nitrate
(d) silver nitrate and potassium chloride

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Correct Answer: (a)
Cloud seeding, a technique to induce rainfall, relies on chemicals with specific crystalline structures to form ice nuclei.

• Option A is true: Silver iodide and potassium iodide are both used in cloud seeding due to their ability to promote ice nuclei formation, facilitating precipitation.
• Option B is false: Silver nitrate is not utilized in artificial rainmaking processes.
• Option C is false: Potassium nitrate is not employed in cloud seeding.
• Option D is false: Neither silver nitrate nor potassium chloride is used for inducing rainfall.

Thus, the correct answer is A.

Q2: Consider the following statements:
Statement I: Studies indicate that carbon dioxide emissions from cement industry account for more than 5% of global carbon emissions.
Statement II: Silica-bearing clay is mixed with limestone while manufacturing cement.
Statement III: Limestone is converted into lime during clinker production for cement manufacturing.
Which one of the following is correct in respect of the above statements?   (2025)
(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

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Correct Answer: (b)

• Statement I is correct: The cement industry accounts for approximately 5-8% of global CO₂ emissions, establishing it as a significant contributor to greenhouse gases.
• Statement II is correct: In cement production, silica-bearing clay is combined with limestone to supply essential minerals such as silicon, aluminum, and iron, which are critical for the final cement product.
• Statement III is correct: During clinker production, limestone (calcium carbonate) is heated, transforming into lime (calcium oxide) and releasing CO₂ through a process called calcination, which is the primary source of carbon emissions in cement manufacturing.

While both Statements II and III are accurate, Statement III directly addresses the primary source of carbon emissions in cement production as described in Statement I.

Q3: With reference to Direct Air Capture, an emerging technology, which of the following statements is/are correct?
I. It can be used as a way of carbon sequestration. 
II. It can be a valuable approach for plastic production and in food processing. 
III. In aviation, it can be a source of carbon for combining with hydrogen to create synthetic low-carbon fuel.
Select the correct answer using the code given below.   (2025)
(a) I and II only
(b) III only
(c) I, II and III
(d) None of the above statements is correct

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Correct Answer: (c)

• Statement I is correct: Direct Air Capture (DAC) technology extracts CO₂ from the atmosphere, enabling carbon sequestration to reduce greenhouse gas levels.
• Statement II is correct: The CO₂ captured through DAC can be utilized in industries, such as producing plastics and supporting food processing applications.
• Statement III is correct: DAC provides CO₂ that, when combined with hydrogen, can be used to create synthetic low-carbon aviation fuels, contributing to sustainable energy solutions.

Thus, all three statements are accurate, making the correct answer C.

Q4: 'Each day is more or less the same, the morning is clear and bright with a sea breeze; as the Sun climbs high in the sky, heat mounts up, dark clouds form, then rain comes with thunder and lightning. But rain is soon over'. (2015)
Which of the following regions is described in the above passage?
(a) Savannah 
(b) Equatorial
(c) Monsoon 
(d) Mediterranean

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Correct Answer: (b)

Q5: If you travel through the Himalayas, you are likely to see which of the following plants naturally growing there? (2014)
1. Oak
2. Rhododendron
3. Sandalwood

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Select the correct answer using the code given below
(a) 1 and 2 only 
(b) 3 only
(c) 1 and 3 only 
(d) 1, 2 and 3
Correct Answer: (a)

Q6: In the grasslands, trees do not replace the grasses as a part of an ecological succession because of- (2013)
(a) insects and fungi
(b) limited sunlight and paucity of nutrients
(c) water limits and fire
(d) None of the above

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Correct Answer: (c)

Q7: Which of the following leaf modifications occurs/occur in desert areas to inhibit water loss? (2013)
1. Hard and waxy leaves
2. Tiny leaves or no leaves
3. Thorns instead of leaves

Select the correct answer using the codes given below.
(a) 1 and 2 only
(b) 2 only
(c) 1 and 3 only
(d) 1, 2 and 3

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Correct Answer: (d)

Q8: “Climate is extreme, rainfall is scanty and the people used to be nomadic herders.” The above statement best describes which of the following regions? (2013)
(a) African Savannah
(b) Central Asian Steppe
(c) North American Prairie
(d) Siberian Tundra

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Correct Answer: (b)

Q9: Which of the following is/are unique characteristic/characteristics of equatorial forests? (2013)
 1. Presence of tall, closely set trees with crowns forming a continuous canopy
 2. Coexistence of a large number of species
 3. Presence of numerous varieties of epiphytes

Select the correct answer using the codes given below:
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3

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Correct Answer: (d)

Q10: Which one of the following is the characteristic climate of the Tropical Savannah Region? (2012)
(a) Rainfall throughout the year
(b) Rainfall in winter only
(c) An extremely short dry season
(d) A definite dry and wet season

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Correct Answer: (b)

Q11: What is the difference between the antelopes Oryx and Chiru?  (2012)
(a) Oryx is adapted to live in hot and arid areas whereas Chiru is adapted to live in steppes and semi-desert areas of cold high mountains.
(b) Oryx is poached for its antlers whereas Chiru is poached for its musk.
(c) Oryx exists in western India only whereas Chiru exists in north-east India only.
(d) None of the statements (a), (b) and (c) given above is correct.

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Correct Answer: (a)

Q12: If a tropical rain forest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is because: (2011)
(a) The soil of rain forest is deficient in nutrients
(b) Propagules of the trees in a rain forest have poor viability
(c) The rain forest species are slow growing
(d) Exotic species invade the fertile soil of rain forest

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Correct Answer: (a)

Q13: The Himalayan Range is very rich in species diversity. Which one among the following is the most appropriate reason for this phenomenon? (2011)
(a) It has high rainfall that supports luxuriant vegetative growth
(b) It is a confluence of different bio-geographical zones
(c) Exotic and invasive species have not been introduced in this region.
(d) It has less human interference

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Correct Answer: (b)

Q14: In India, which type of forest among the following occupies the largest area? (2010)
(a) Montane Wet Temperate Forest
(b) Sub-tropical Dry Evergreen Fores
(c) Tropical Moist Deciduous Forest
(d) Tropical Wet Evergreen Forest

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Correct Answer: (c)

Q15: The approximate representation of land use classification in India is (2010)
(a) Net area sown 25%; forest 33%; other areas 42%
(b) Net area sown 58%; forest 17%; other areas 25%
(c) Net area sown 43%; forest 29%; other areas 28%
(d) Net area sown 47%; forest 23%; other areas 30%

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Correct Answer: (d)

Q16: Consider the following statements: (2010)
1. Biodiversity hotspots are located only in tropical regions.
2. India has four biodiversity hotspots i.e., Eastern Himalayas, Western Himalayas, Western Ghats and Andaman and Nicobar Islands.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

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Correct Answer: (d)

Q17: Consider the following statements: (2010)
1. The Taxus tree naturally found in the Himalayas.
2. The Taxus tree is listed in the Red Data Book.
3. A drug called “taxol” is obtained from Taxus tree is effective against Parkinson’s disease.

Which of the statements given above is/are correct?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3

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Correct Answer: (b)
Taxus wallichiana Zucc., is found in temperate forests of Asia ranging from Afghanistan through the Himalayas to the Philippines with elevation range of 1500-3500 m. it is small to medium-sized tree, with red ‘berries’ (seeds covered by arils), valuable for Taxol extraction. It is used in preparation of anticancer drugs, in addition to other medicinal uses in Ayurveda and Tibetan Medicine. In 1995, Taxus wallichiana was listed in Appendix II of CITES. Its legal status is that it has been included in the Red Data Book.

Q18: India is a party to the Ramsar Convention and has declared many areas as Ramsar Sites. Which of the following statements best describes as to how we should maintain these sites in the context of this Convention?
(a) Keep all the sites completely inaccessible to man so that they will not be exploited
(b) Conserve all the sites through ecosystem approach and permit tourism and recreation only
(c) Conserve all the sites through ecosystem approach for a period without any exploitation, with specific criteria and specific period for each site, and then allow sustainable use of then by future generations.
(d) Conserve all the sites through ecosystem approach and allow their simultaneous sustainable use

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Correct Answer: (d)
 The Ramsar Convention (The Convention on Wetlands of International Importance, especially as Waterfowl Habitat) is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on an loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural, scientific, and recreational value. Ramsar Convention calls for sustainable use of preserved sites in such a way that people living there shall not be deprived and the resources are also maintained for present and future use.

Q19: Which one of the following is not essentially a species of the Himalayan vegetation? (2008)
(a) Juniper
(b) Mahogany
(c) Silver fir
(d) Spruce

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Correct Answer: (b)

Q20: Consider the following statements: (2005)
1. The forest cover in India constitutes around 20% of its geographical area. Out of the total forest cover, dense forest constitutes around40%.
2. The National Forestry Action Programme aims at bringing one-third of the area of Indian under tree/ forest cover.

Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

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Correct Answer: (b)

Q21: Amongst the following Indian States which one has the minimum total forest cover? (2004)
(a) Sikkim
(b) Goa
(c) Haryana
(d) Kerala

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Correct Answer: (c)

Q22: Assertion (A): Unlike temperate forests, the tropical rain forests, if cleared, can yield productive farmland that can support intensive agriculture for several years even without chemical fertilizers. Reason (R): The primary productivity of the tropical rain forest is very high when compared to that of temperate forests. (2003)
(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true

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Correct Answer: (d)
A is wrong R is correct. In tropical rainforests because of the rainfall throughout the year, leaching of minerals occur. Due to high temperatures bacterial activity is enormous, there by humus content in the soil decreases. To raise crops in this region requires application of chemical fertilizers.

Q23: Which one among the following covers the highest percentage of forest area in the world? (2003)
(a) Temperate Coniferous forests
(b) Temperature Deciduous forests
(c) Tropical Monsoon forests
(d) Tropical Rain forests

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Correct Answer: (a)

Q24: Open stunted trees having long roots and sharp thorns or spines are commonly found in: (2002)
(a) Eastern Orissa
(b) North-Eastern Tamil Nadu
(c) Siwaliks and Terai region
(d) Western Andhra Pradesh

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Correct Answer: (d)
 The tropical semi-desert type merges into the tropical thorn forests when natural vegetation consists of open stunted forest with widely scattered trees and bushes and having long roots and sharp thorns. Eastern Rajasthan, South-west Punjab and Haryana, Bundelkhand region of Madhya Pradesh, Southern Karnataka and adjoining Andhra Pradesh have this type of vegetation.

Q25: Match List I with List II and select the correct answer using the codes given below the lists: (2002)
 List I (Mangrove) List II (State)
A. Achra Ratnagiri        1. Karnataka
B. Coondapur                  2. Kerala
C. Pichavaram                 3. Andhra Pradesh
D. Vembanad                   4. Maharashtra
5. Tamil Nadu

A B C D
(a) 2 1 5 4
(b) 4 5 3 2
(c) 2 5 3 4
(d) 4 1 5 2

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Correct Answer: (d)

Q26: Consider the following ecosystems: (2002)
1. Taiga
2. Tropical evergreen
3. Tropical deciduous
4. Tundra

The correct sequence in decreasing order of the albedo values of these ecosystems is
(a) 1, 4, 3, 2
(b) 4, 1, 2, 3
(c) 4, 1, 3, 2
(d) 1, 4, 2, 3

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Correct Answer: (c)
The earth’s average albedo is 34%. But it varies according to the texture and colour of the surface. For fresh snow, the albedo is 85%, for forests, it is 5-10%. Accordingly, the order is Tundra – Taiga – Tropical evergreen – Tropical deciduous.

Q27: With reference to ‘Eco-Sensitive Zones’, which of the following statements is/are correct?
1. Eco-Sensitive Zones are the areas that are declared under the Wildlife (Protection) Act, 1972.
2. The purpose of the declaration of Eco-Sensitive Zones is to prohibit all kinds of human activities, in those zones except agriculture.

Select the correct answer using the code given below. (2014)
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

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Correct Answer: (d)