Environment & Ecology › Ecosystems & Ecology Concepts – UPSC Prelims PYQs

Which of the following best explain(s) the rationale for protecting mangrove ecosystems in the context of climate resilience ?

1. Mangroves reduce tidal energy and store freshwater, making them ideal sites for paddy cultivation in saline estuarine belts.
2. Their salt-sensitive roots filter seawater, making mangroves key to converting coastal land into freshwater aquaculture zones.
3. By withstanding tidal surges and offering biomass resources, mangroves function both as natural bio-shields and livelihood bases for rural communities.

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Consider the following statements : 1. 2. 3.

Which of the statements given above are correct ?

Which one of the following shows a unique relationship with an insect that has coevolved with it and that is the only insect that can pollinate this tree ?

Consider the following : 1. 2. 3.

How many of the above have poisonous species among them ?

Consider the following trees :

1. Jackfruit (Artocarpus heterophyllus)
2. Mahua (Madhuca indica)
3. Teak (Tectona grandis)

How many of the above are deciduous trees?

With reference to India’s projects on connectivity, consider the following statements :

1. East-West Corridor under Golden Quadrilateral Project connects Dibrugarh and Surat.
2. Trilateral Highway connects Moreh in Manipur and Chiang Mai in Thailand via Myanmar.
3. Bangladesh-China-India-Myanmar Economic Corridor connects Varanasi in Uttar Pradesh with Kunming in China.

How many of the above statements are correct?

“Biorock technology” is talked about in which one of the following situations ?

Certain species of which one of the following organisms are well known as cultivators of fungi ?

In the nature, which of the following is/are most likely to be found surviving on a surface without soil?

1. Fern
2. Lichen
3. Moss
4. Mushroom

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Consider the following kinds of organisms :

1. Copepods
2. Cyanobacteria
3. Diatoms
4. Foraminifera

Which of the above are primary producers in the food chains of oceans?

Consider the following animals :

1. Hedgehog
2. Marmot
3. Pangolin To reduce the chance of being captured by predators, which of the above organisms rolls up/roll up and protects/protect its/their vulnerable parts?

Which one of the following is a filter feeder?

Which of the following are detritivores?

1. Earthworms
2. Jellyfish
3. Millipedes
4. Seahorses
5. Woodlice

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"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

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

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Consider the following statements :

1. Some species of turtles are herbivores.
2. Some species of fish are herbivores.
3. Some species of marine mammals are herbivores.
4. Some species of snakes are viviparous.

Which of the statements given above are correct?

Which of the following leaf modifications occur(s) in the desert areas to inhibit water loss ?

1. Hard and waxy leaves
2. Tiny leaves
3. Thorns instead of leaves

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Consider the following statements :

1. Most of the world's coral reefs are in tropical waters.
2. More than one-third of the world's coral reefs are located in the territories of Australia, Indonesia and Philippines.
3. Coral reefs host far more number of animal phyla than those hosted by tropical rainforests.

Which of the statements given above is/are correct ?

Due to some reasons, if there is a huge fall in the population of species of butterflies, what could be its likely consequence/consequences ?

1. Pollination of some plants could be adversely affected.
2. There could be a drastic increase in the fungal infections of some cultivated plants.
3. It could lead to a fall in the population of some species of wasps, spiders and birds.

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Which one of the following regions of India has a combination of mangrove forest, evergreen forest and deciduous forest?

In India, in which one of the following types of forests is teak a dominant tree species?

Which one of the following is the best description of the term 'ecosystem'?

If you walk through countryside, you are likely to see some birds stalking alongside the cattle to seize the insects disturbed by their movement through grasses. Which of the following is/are such bird/birds?

1. Painted Stork
2. Common Myna
3. Black-necked Crane

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Which of the following have coral reefs?

1. Andaman and Nicobar Islands
2. Gulf of Kachchh
3. Gulf of Mannar
4. Sunderbans

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Which one of the following is the correct sequence of a food chain?

In the grasslands, trees do not replace the grasses as a part of an ecological succession because of

Which one of the following is the correct sequence of ecosystems in the order of decreasing productivity?

With reference to food chains in ecosystems, consider the following statements:

1. A food chain illustrates the order in which a chain of organisms feed upon each other.
2. Food chains are found within the populations of a species.
3. A food chain illustrates the numbers of each organism which are eaten by others.

Which of the statements given above is/are correct?

Which one of the following terms describes not only the physical space occupied by an organism, but also its functional role in the community of organisms?

With reference to the food chains in ecosystems, which of the following kinds of organism is/are known as decomposer organism/organisms?

1. Virus
2. Fungi
3. Bacteria

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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

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Which of the following leaf modifications occurs/occur in desert areas to inhibit water loss?

1. Hard and waxy leaves
2. Tiny leaves or no leaves
3. Thorns instead of leaves

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Consider the following kinds of organisms :

1. Bat
2. Bee
3. Bird

Which of the above is/are pollinating agent/agents?

The Millennium Ecosystem Assessment describes the following major categories of ecosystem services—provisioning, supporting, regulating, preserving and cultural. Which one of the following is supporting service?

What would happen if phytoplankton of an ocean is completely destroyed for some reason?

1. The ocean as a carbon sink would be adversely affected.
2. The food chains in the ocean would be adversely affected.
3. The density of ocean water would drastically decrease.

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In the context of ecosystem productivity, marine upwelling zones are important as they increase the marine productivity by bringing the

1. Decomposer microorganisms to the surface,
2. Nutrients to the surface,
3. Bottom-dwelling organisms to the surface.

Which of the statements given above is/are correct?

If a tropical rain forest is removed, it does not regenerate quickly as compared to a tropical deciduous forest. This is because

Biodiversity forms the basis for human existence in the following ways:

1. Soil formation
2. Prevention of soil erosion
3. Recycling of waste
4. Pollination of crops

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A new type of El Nino called El Nino Modoki appeared in the news. In this context, consider the following statements:

1. Normal El Nino forms in the Central Pacific ocean whereas El Nino Modoki forms in Eastern Pacific ocean.
2. Normal El Nino results in diminished hurricanes in the Atlantic ocean but El Nino Modoki results in a greater number of hurricanes with greater frequency.

Which of the statements given above is/are correct?

Some species of plants are insectivorous. Why ?

In India, which type of forest among the following occupies the largest area?

King Cobra is the only snake that makes its own nest. Why does it make its nest?

Consider the following names :

1. Ike
2. Kate
3. Gustav

Which of the above are the names of hurricanes that had occurred very recently ?

For which one of the following snakes is the diet mainly composed of other snakes?

The largest coral reef in the world is found near the coast of which one of the following countries?

Assertion (A): Unlike temperate forests, the tropical rain forests, if cleared, can yield productive farm-land 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 the temperate forests.

Which one of the following animals is monogamous?

A class of animals known as Marsupials is a characteristic feature of

Within biological communities, some species are important in determining the ability of a large number of other species to persist in the community. Such species are called

Which one of the following is a useful functional association between fungi and the roots of higher plants?