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Q21·GS Paper 1 · Prelims 2017

Ecological consequences of species decline

EnvironmentBiodiversity and ecosystem servicesStatement-basedMediumStatic

Question

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

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

Select the correct answer using the code given below:

  1. 1.

    Pollination of some plants could be adversely affected.

  2. 2.

    There could be a drastic increase in the fungal infections of some cultivated plants.

  3. 3.

    It could lead to a fall in the population of some species of wasps, spiders and birds.

Options

a

1 only

b

2 and 3 only

c

1 and 3 only

Answer
d

1, 2 and 3

Explanation

Statement 1 is correct: Butterflies are significant pollinators; a decline in their population would adversely affect pollination of many plants. Statement 3 is correct: Wasps, spiders, and birds that feed on butterflies would experience a population decline due to loss of food source. Statement 2 is incorrect: There is no direct causal link between butterfly population decline and increased fungal infections in plants. Fungal infections depend on fungal spore dispersal, humidity, and plant immunity, not butterfly abundance. > KEY INSIGHT: Butterfly decline affects pollination services (mutualism) and predator-prey food chains, but not fungal disease dynamics. Answer: (c).

Question details

Year

2017

Paper

GS Paper 1

Question

Q21

Subject

Environment

Sub-topic

Biodiversity and ecosystem services

Type

Statement-based

Difficulty

Medium

Nature

Static

Source hint

NCERT Biology, Ecology Chapter

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