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 41–50 of 80 questions
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q41. Consider the following statements regarding cacti and other desert vegetation adaptations: I. They often possess Crassulacean Acid Metabolism (CAM) to fix carbon dioxide at night. II. Leaves are frequently reduced to spines to decrease surface area. III. Stems are typically photosynthetic and succulent. IV. They continuously transpire water during the hottest part of the day to stay cool. V. They have an extensive network of shallow roots to capture brief showers. Which of the above statement(s) is/are correct?
Explanation
Desert plants like cacti employ specialized strategies to survive extreme aridity. Many use CAM photosynthesis to fix carbon at night, minimizing daytime water loss. Their leaves are often reduced to spines, and their succulent stems store water and perform photosynthesis. Additionally, shallow root networks quickly capture rare rainfall. Constant transpiration during the day is avoided as it would cause dehydration.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q42. Which of the following features is incorrectly paired with its ecological function in Mangrove forests?
Explanation
Mangroves use several adaptations for coastal survival. Stilt roots provide stability against tides, and salt-excreting leaves manage salinity. Pneumatophores allow roots to breathe in oxygen-poor mud. However, vivipary involves seeds germinating while still attached to the parent tree, allowing them to develop into seedlings before falling. This gives them a better chance of establishing themselves in the shifting intertidal environment.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q43. Match List I (Type of Coral Reef) with List II (Description) and select the correct answer using the codes given below.
Type of Coral Reef
Description
A. Fringing Reef
i. A ring-shaped coral reef enclosing a lagoon
B. Barrier Reef
ii. A reef directly attached to the shore or bordering it with a shallow channel
C. Atoll
iii. Small, isolated reef platforms found within a lagoon
D. Patch Reef
iv. A reef separated from the mainland or island by a deep, wide lagoon Options:
Explanation
Coral reefs are categorized by their structure and relationship to land. Fringing reefs are directly attached to shores. Barrier reefs are separated from land by a wide lagoon. Atolls are ring-shaped reefs that enclose a central lagoon, often forming after a volcanic island subsides. Patch reefs are small, isolated platforms found within larger lagoon systems, providing localized habitats for marine life.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q44. Consider the following statements regarding the climatic limits of natural vegetation: I. The timberline marks the maximum altitude or latitude beyond which trees cannot grow due to environmental conditions. II. Beyond the snowline, permanent snow limits all forms of macroscopic plant life. III. The timberline and the snowline exist at the exact same altitude on any given mountain range. Which of the above statement(s) is/are incorrect?
Explanation
The timberline and snowline are critical ecological boundaries on mountains. The timberline marks the limit beyond which trees cannot grow due to cold and wind. The snowline indicates where permanent snow begins, preventing macroscopic plant life. While both are determined by climate, they do not exist at the same altitude; the timberline always occurs at a lower elevation than the snowline.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q45. Biomes are primarily classified into terrestrial and aquatic ecosystems. Which of the following is not considered a terrestrial biome?
Explanation
Terrestrial biomes are large-scale land-based communities defined by climate and vegetation, such as the taiga, savanna, and temperate grasslands. In contrast, the pelagic zone is an aquatic environment referring to the open ocean water column. Aquatic biomes are classified by different factors like salinity and depth, distinguishing them from the vegetation-based classification used for land-based ecosystems across the globe.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q46. The Tropical Rainforest biome is distributed near the equator across multiple continents. Which of the following regions does not contain significant areas of tropical rainforest?
Explanation
Tropical rainforests are concentrated near the equator where heat and rainfall are consistent. This includes the Amazon Basin, the Congo Basin, and Southeast Asia. The Patagonian region, located at the southern tip of South America, is characterized by cold, arid, or temperate climates and contains grasslands and shrublands rather than the lush, evergreen vegetation typical of the tropics near the equator.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q47. Consider the following statements regarding the distribution and characteristics of Tropical Deciduous (Monsoon) forests: I. They are predominantly found in India, Myanmar, Thailand, and parts of Northern Australia. II. Their structure is largely dependent on the seasonal reversal of winds. III. These forests generally support a higher density of tall, evergreen trees compared to rainforests. IV. They yield commercially valuable hardwood timbers like Sal and Teak. Which of the above statement(s) is/are correct?
Explanation
Tropical deciduous forests, often called monsoon forests, are common in India and Southeast Asia. They are adapted to seasonal rainfall patterns driven by monsoon winds. These forests yield valuable hardwoods like teak and sal, which are commercially significant. Unlike rainforests, they have a less complex structure and lose their leaves during the dry season to conserve water and survive.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q48. In the Tropical Savanna biome, trees are widely scattered rather than forming a closed canopy. What is the primary cause of this specific vegetation structure?
Explanation
The open structure of the tropical savanna is maintained by several interacting factors. A long dry season limits tree growth, while frequent seasonal fires destroy many saplings. Additionally, the presence of large grazing herbivores prevents the development of a dense forest canopy. These environmental pressures ensure that grasses remain the dominant vegetation, with trees appearing only as widely scattered individuals.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q49. Match List I (Grassland) with List II (Continent) and select the correct answer using the codes given below.
Grassland
Continent
A. Steppes
i. North America
B. Pampas
ii. Eurasia
C. Veld
iii. South America
D. Prairies
iv. Africa Options:
Explanation
Grasslands around the world are identified by specific names based on their continental location. Steppes are found in Eurasia, while Prairies dominate the interior of North America. South America is home to the fertile Pampas, and the Veld is the characteristic grassland of South Africa. Each of these biomes supports unique wildlife and has been significantly modified for agriculture and grazing.
RAS PrelimsWorld Geography · Natural Vegetation and Biomes
Q50. In the temperate rainforests of the Pacific coast of North America, which species of tree is famously known for its enormous height and longevity?
Explanation
The coastal redwood is a characteristic species of the temperate rainforests along the Pacific coast of North America. These trees are renowned for being among the tallest and oldest living organisms on Earth. They thrive in the mild, moist climate and persistent fog of the region, which provides the consistent hydration necessary to support such massive biological structures over many centuries.
Answer key for these questions
Q
Correct answer
41
(a) I, II, III and V
42
(a) Vivipary : Seeds detach and fall directly into the mud before developing roots
43
(a) A-ii, B-iv, C-i, D-iii
44
(b) III only
45
(c) Pelagic zone
46
(d) The Patagonian region
47
(a) I, II and IV
48
(b) A mix of long dry seasons, seasonal fires, and large herbivores limiting tree density
49
(a) A-ii, B-iii, C-iv, D-i
50
(a) Coastal Redwood (Sequoia sempervirens)
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.
