PREVIOUS YEAR QUESTIONS (PRELIMS)
Q.1 ) Consider the following statements: UPSC (2023)
Statement-I: The soil in tropical rain forests is rich in nutrients.
Statement-II: The high temperature and moisture of tropical rain forests cause dead organic matter in the soil to decompose quickly.
Which one of the following is correct in respect of the above statements?
- Both Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
- Both Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
- Statement-I is correct but Statement-II is incorrect
- Statement-I is incorrect but Statement-II is correct
Answer: D
Explanation:
- Statement-I: Incorrect. The soil in tropical rain forests is rich in nutrients.
The soils in tropical rainforests are generally nutrient-poor because:
- Heavy rainfall leaches nutrients from the soil.
- Most of the nutrients are stored in the dense vegetation and not in the soil itself.
Thus, the soil fertility is low despite the lush vegetation.
- Statement-II: Correct. The high temperature and moisture of tropical rain forests cause dead organic matter in the soil to decompose quickly.
The warm, moist climate promotes rapid microbial activity, resulting in fast decomposition of organic matter. However, the nutrients released are quickly taken up by plants or washed away by rain, leaving the soil poor.
Q.2) Which types of vegetation will you find on the way as you travel from Bikaner to Konark by road by shortest distance? CDS-II (2022)
- Tropical thorny, Desert, Moist deciduous, Mangrove
- Desert, Tropical thorny, Moist deciduous, Mangrove
- Moist deciduous, Tropical thorny, Mangrove, Desert
- Desert, Tropical thorny, Mangrove, Moist deciduous
Answer: B
Explanation:
- Bikaner (Rajasthan): Located in the Thar desert → Desert vegetation
- Moving eastward across Rajasthan → semi-arid Tropical thorny vegetation
- Further east towards central and eastern India → Moist deciduous forests (in states like Madhya Pradesh, Odisha)
- Near Konark (Odisha coast) → presence of Mangroves near coastal wetlands
Hence, along the shortest road route, these vegetation types appear in sequence:
Desert → Tropical thorny → Moist deciduous → Mangrove
Q.3) Which one of the following set of trees does not belong to Temperate Floral Zone of Himalaya? CDS-II (2023)
- Cashewnut and Magnolia
- Oak and Maple
- Rhododendrons
- Birch and Laurels
Answer: A
Explanation:
- The Temperate Floral Zone of Himalaya supports vegetation adapted to cool and moderate climates. Common species include:
- Oak, Maple, Rhododendrons, Birch, Laurels
- Cashewnut (Anacardium occidentale) is a tropical tree, mainly grown in warm coastal regions.
- Magnolia does occur in the Himalayas, but generally in the subtropical and temperate zones. However, Cashewnut clearly does not belong to the temperate zone of the Himalaya, making this pair incorrect for this zone.
Q.4) The greatest diversity of animal and plant species is found in: CAPF (2023)
- Temperate forests
- Deserts and Savannas
- Arctic and Alpine systems
- Tropical moist forests
Answer: D
Explanation:
- Tropical moist forests (or tropical rainforests) have the highest biodiversity on Earth.
- These forests are located near the equator and have warm temperatures and high rainfall, which create ideal conditions for a wide variety of plants and animals.
- They support:
- Thousands of tree species, including hardwoods and canopy trees
- Mammals, birds, reptiles, amphibians, insects in immense diversity
- Temperate forests, deserts, and arctic/alpine zones have much lower species diversity compared to tropical moist forests.
Q.5) As per India State of Forest Report 2021, which one of the following states is not among the top three with reference to maximum area under forest? CDS-II (2024)
- Arunachal Pradesh
- Chhattisgarh
- Madhya Pradesh
- Maharashtra
Answer: D
Explanation:
According to the India State of Forest Report (ISFR) 2021, the top three states in terms of largest forest area (in absolute terms) are:
- Madhya Pradesh
- Arunachal Pradesh
- Chhattisgarh
These three states have the largest area under forests in India.
Although Maharashtra has a significant forest cover, it is not among the top three in terms of total forest area.
Data from ISFR 2021:
Rank | State | Forest Area (sq km) |
1 | Madhya Pradesh | ~77,493 |
2 | Arunachal Pradesh | ~66,688 |
3 | Chhattisgarh | ~55,611 |