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Topics / Geography

Physical Geography Biosphere

Asked 13 times in UPSC Prelims · first asked 1995 · last asked 2025

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All 13 questions

Newest first — expand for options, answers, and explanations

With reference to the planet Earth, consider the following statements: I. Rain forests produce more oxygen than that produced by oceans. II. Marine phytoplankton and photosynthetic bacteria produce about 50% of world's oxygen. III. Well-oxygenated surface water contains several folds higher oxygen than that in atmospheric air. Which of the statements given above is/are correct?

2025Geography
AI and II
BII only
CI and III
DNone of the above statements is correct

Explanation

Marine phytoplankton and photosynthetic bacteria are responsible for producing approximately 50% of the world's oxygen. This statement is correct because these organisms play a crucial role in oxygen production in marine ecosystems, contributing significantly to the Earth's oxygen supply.

Consider the following trees: 1. Jackfruit (Artocarpus heterophyllus) 2. Mahua (Madhuca indica) 3. Teak (Tectona grandis). How many of the above are deciduous trees?

2023Geography
AOnly one
BOnly two
CAll three
D

Explanation

Jackfruit and Mahua are deciduous trees, which shed their leaves seasonally. Teak, on the other hand, is a tropical hardwood tree that is evergreen, meaning it retains its leaves throughout the year.

Consider the following statements: 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?

2023Geography
ABoth Statement-I and Statement-II are correct and Statement-II is the correct explanation for Statement-I
BBoth Statement-I and Statement-II are correct and Statement-II is not the correct explanation for Statement-I
CStatement-I is correct but Statement-II is incorrect
DStatement-I is incorrect but Statement-II is correct

Explanation

The soil in tropical rain forests is not necessarily rich in nutrients due to the rapid decomposition of organic matter caused by high temperatures and moisture. This rapid decomposition leads to the nutrients being quickly absorbed by plants, leaving the soil relatively poor in nutrients.

The vegetation of savannah consists of grassland with scattered small trees but extensive areas have no trees. The forest development in such areas is generally kept in check by one or more or a combination of some conditions. Which of the following are such conditions? 1. Burrowing animals and termites 2. Fire 3. Grazing herbivores 4. Seasonal rainfall 5. Soil properties

2021Geography
A1 and 2
B4 and 5
C2 3 and 4
D1 3 and 5

Explanation

In savannah areas, the forest development is controlled by conditions such as fire, grazing herbivores, and seasonal rainfall. These factors prevent the growth of extensive tree cover in savannah regions, leading to the characteristic grassland with scattered trees landscape.

Leaf litter decomposes faster than in any other biome and as a result the soil surface is often almost bare. Apart from trees the vegetation is largely composed of plant forms that reach up into the canopy vicariously by climbing the trees or growing as epiphytes rooted on the upper branches of trees. This is the most likely description of

2021Geography
Aconiferous forest
Bdry deciduous forest
Cmangrove forest
Dtropical rain forest

Explanation

The description provided in the question, with fast decomposition of leaf litter, sparse soil surface, and vegetation climbing trees or growing as epiphytes, aligns with the characteristics of a tropical rainforest biome. Tropical rainforests have a high rate of decomposition due to warm and moist conditions, leading to rapid recycling of nutrients. The presence of diverse plant forms, including climbers and epiphytes, is a common feature in the dense canopy of tropical rainforests.

Which of the following is/are unique characteristic/characteristics of equatorial forests? 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.

2013Geography
A1 only
B2 and 3 only
C1 and 3 only
D1, 2 and 3

Explanation

Equatorial forests are characterized by tall trees closely packed together, creating a continuous canopy. These forests are known for hosting a wide array of species and numerous types of epiphytes. The canopy, which serves as the top layer of the forest, shelters a rich biodiversity and is home to a diverse range of epiphytes.

'Climate is extreme, rainfall is scanty and the people used to be nomadic herders.' The above statement best describes which of the following regions?

2013Geography
AAfrican Savannah
BCentral Asian Steppe
CNorth American Prairie
DSiberian Tundra

Explanation

The region being described as having extreme climate, low rainfall, and a history of nomadic herders is the Central Asian Steppe. This region includes countries like Kazakhstan, Turkmenistan, Uzbekistan, and Mongolia. The climate in the Central Asian Steppe is challenging, characterized by dust storms and minimal precipitation.

A geographic area with an altitude of 400 metres has specific characteristics. If this geographic area were to have a natural forest, which one of the following would it most likely be?

2010Geography
AMoist temperate coniferous forest
BMontane subtropical forest
CTemperate forest
DTropical rain forest

Explanation

A geographic area at an altitude of 400 metres is most likely to have a tropical rainforest if it were to have a natural forest. Tropical rainforests are characterized by their warm and humid climate, with temperatures typically ranging from 21 to 30 degrees Celsius.

A geographic region has the following distinct characteristics: 1. Warm and dry climate 2. Mild and wet winter 3. Evergreen Oak trees The above features are distinct characteristics of which one of the following regions?

2010Geography
AMediterranean
BEastern China
CCentral Asia
DAtlantic coast of North America

Explanation

The given geographic region is known for its warm and dry climate, mild and wet winter, and the presence of Evergreen Oak trees. These unique features are typically found in which of the following regions? (a) Mediterranean (b) Eastern China (c) Central Asia (d) Atlantic coast of North America The correct answer is (a) Mediterranean.

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.

2003Geography
ABoth A and R are individually true and R is the correct explanation of A.
BBoth A and R are individually true but R is not the correct explanation of A
CA is true but R is false
DA is false but R is true

Explanation

In tropical rainforests, the soil loses nutrients constantly due to consistent rainfall. To make up for this depletion, additional minerals and essential elements must be added through the use of chemical fertilizers.

Consider the following ecosystems: 1. Taiga 2. Tropical Evergreen 3. Tropical Deciduous 4. Tundra The correct sequence in decreasing order of the Albedo values of these ecosystems is:

2002Geography
A1, 4, 3, 2
B4, 1, 3, 2
C4, 1, 2, 3
D1, 4, 2, 3

Explanation

In terms of decreasing Albedo values, the correct sequence for the listed ecosystems is Tundra, Taiga, Tropical Deciduous, and Tropical Evergreen.

Assertion (A): Mangroves are very specialised forest eco-systems of tropical and sub-tropical regions bordering certain sea coasts. Reason (R): They stabilise the shoreline and act as bulwark against encroachments by the sea. In the context of the above two statements, which one of the following is correct?

1996Geography
ABoth A and R are true and R is the correct explanation of A
BBoth A and R are true but R is not a correct explanation of A
CA is true but R is false
DA is false but R is true

Explanation

Mangroves are specialized forest ecosystems located in tropical and sub-tropical regions near certain sea coasts. They play a crucial role in stabilizing the shoreline and act as a protective barrier against sea encroachment. In this context, it is accurate to say that both statements are true, and the reason effectively explains the assertion.

Which one of the following does not belong to biosphere reserves set-up so far?

1995Geography
AGreat Nicobar
BSunderbans
CNanda Devi
DGulf of Kutch

Explanation

The correct answer is option (d), Gulf of Kutch. This area was designated as a biosphere reserve in 2008. India currently has 18 officially recognized biosphere reserves.