Q61. The tropical savannas are known by different regional names. The "Llanos" and "Campos" are vast tropical savanna regions located respectively in:
Natural Vegetation and Biomes: RAS Prelims MCQs
80 RAS Prelims MCQs on natural vegetation and biomes ask about the forest types of the world, their layers, trees and soils. The Amazon rainforest, temperate rainforests, the boreal forest, the temperate deciduous forest and the Great Barrier Reef are tested, and each explanation links the biome to its climate and location.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 61–70 of 80 questions
Q62. Which vegetation type is primarily characterized by ‘sclerophyllous’ (hard-leaved) plants?
Explanation
Mediterranean vegetation is characterized by sclerophyllous plants, which have hard, leathery, and often small leaves. This adaptation is essential for surviving the hot, dry summers typical of the Mediterranean climate. The thick leaves reduce water loss through transpiration and help the plants endure long periods of drought. Examples include various species of evergreen oaks, shrubs, and aromatic herbs.
Q63. Temperate grassland biomes boast some of the most fertile soils in the world. Which of the following is the primary cause for the accumulation of deep, dark humus in these soils?
Explanation
The high fertility and deep humus layer in temperate grassland soils result from the specific life cycle of grasses. Each year, a significant portion of the dense root systems and above-ground foliage dies and decomposes. This continuous addition of organic matter, combined with a climate that slows down decomposition slightly compared to the tropics, leads to the accumulation of nutrient-rich Mollisols.
Q64. Which of the following is an incorrectly matched feature of the Temperate Deciduous Forest biome?
Explanation
Temperate deciduous forests are defined by their four distinct seasons and broad-leaved trees that shed leaves in winter. Their soils are generally fertile and well-developed, unlike the soils of the tundra which are permanently frozen. The process of leaf shedding, or abscission, is a vital adaptation that allows these trees to survive the cold winters when liquid water is unavailable.
Q65. What is the most distinguishing difference between a Temperate Rainforest and a Tropical Rainforest?
Explanation
The most significant difference between temperate and tropical rainforests lies in their temperature patterns and seasonality. Tropical rainforests are warm and humid throughout the year without distinct seasons. In contrast, temperate rainforests experience cooler temperatures and significant seasonal variation, including cooler winters. Both receive high rainfall, but the cooler climate of temperate rainforests results in different dominant tree species and biodiversity.
Q66. Which of the following correctly describes the biodiversity of the Boreal Forest (Taiga)?
Explanation
The boreal forest, or taiga, exhibits relatively low plant species diversity compared to other forest biomes. It is characterized by vast, uniform stands of coniferous trees like spruce, fir, and pine. The harsh climate, with long, cold winters and a short growing season, limits the number of species that can survive. This simplicity makes the biome highly vulnerable to specific pests.
Q67. Vegetation in the Tundra biome is uniquely adapted to survive extremely short growing seasons and freezing temperatures. Which of the following plant types is not typically found in the Tundra?
Explanation
Tundra vegetation must survive extreme cold and very short growing seasons. Common plants include mosses, lichens, and dwarf shrubs that grow close to the ground for protection. Epiphytic orchids are not found in the tundra; they are characteristic of warm, humid tropical rainforests. The lack of tall trees and persistent freezing temperatures make the tundra environment unsuitable for such epiphytes.
Q68. Certain desert plants are termed "ephemerals." How do these plants survive the harsh desert climate?
Explanation
Ephemerals are desert plants that survive by avoiding drought altogether. Their seeds can remain dormant in the soil for years until a rare rainfall event occurs. When it rains, these plants germinate, grow, flower, and produce new seeds in a very short period, often just a few weeks. This rapid life cycle ensures the next generation survives before the desert dries.
Q69. Mangroves possess several unique adaptations to survive in harsh coastal environments. Which of the following is not an adaptation typical of mangrove trees?
Explanation
Mangroves utilize various adaptations for coastal life, including stilt roots for stability, pneumatophores for aeration, and viviparous germination. They often have thick, succulent leaves to store water and manage salt. Needle-like leaves are not an adaptation of mangroves; instead, they are characteristic of coniferous trees in cold boreal or alpine regions, where they help reduce water loss and manage snow.
Q70. Corals depend on a symbiotic relationship with microscopic algae called zooxanthellae. Which of the following statements about this relationship is incorrect?
Explanation
The relationship between corals and zooxanthellae is a vital mutualistic symbiosis. The algae live within the coral’s tissues, providing food through photosynthesis and assisting in waste removal. While they facilitate the calcification process, the coral polyps themselves are responsible for secreting the calcium carbonate that forms the reef structure. Without these algae, corals lose their primary energy source and perish.Answer key for these questions
| Q | Correct answer |
|---|---|
| 61 | (c) Venezuela and Brazil |
| 62 | (d) Mediterranean Vegetation |
| 63 | (a) The annual decay of extensive grass root systems and above-ground biomass |
| 64 | (b) Soil : Extremely acidic and permanently frozen (permafrost) |
| 65 | (b) Temperate rainforests have seasonal variation; tropical rainforests stay warm |
| 66 | (a) Low plant species diversity, often consisting of extensive tracts of conifer species |
| 67 | (c) Epiphytic orchids |
| 68 | (d) Completing a rapid life cycle quickly following rare rainfall events |
| 69 | (c) Needle-like leaves |
| 70 | (b) Zooxanthellae are entirely responsible for secreting the calcium carbonate skeleton of the reef |
Key facts from Natural Vegetation and Biomes
- The dense, broad-leaved evergreen forest of the Amazon Basin is called Selvas.
- The layers of a tropical rainforest from the top are emergent layer, canopy, understory and forest floor; epiphytes grow on other plants for support without being parasites.
- Podzolization is the soil process most dominant in the Boreal Forest (Taiga).
- Boreal forests have extensive pure stands of a single species, which simplifies commercial lumbering.
- Temperate deciduous forests are found in eastern United States, western Europe and eastern China.
- The Coastal Redwood is a famous tree of the Pacific coast temperate rainforest; the Great Barrier Reef lies off the north-east coast of Australia.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Natural Vegetation and Biomes?
This page has 80 practice MCQs on Natural Vegetation and Biomes (World Geography). Each has the correct answer, and most have an explanation.
What are Selvas?
The local name for the dense, broad-leaved evergreen forest of the Amazon Basin. The high rainfall and heat all year round produce a tall forest with several layers, which makes it the richest rainforest on the planet.
What are epiphytes?
Plants that grow on other plants, mostly trees, for physical support, without being parasites. In tropical rainforests orchids and ferns are epiphytes, and they get light by growing high on tree trunks and branches.
Where is podzolization most common?
In the Boreal Forest, or Taiga, biome. The cold, wet climate and acidic needle litter wash minerals out of the upper soil, producing the grey, infertile podzol soils typical of coniferous forests.