Prelims 2011 · archive
EasyBiodiversity 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
Select the correct answer using the codes given below:
Answer & explanation
Answer: (d) 1, 2, 3 and 4
All four are ecosystem services that living organisms provide. Soil organisms build soil and decompose waste, plant cover and soil biota hold soil in place, and insects and other animals pollinate crops. Each of these services depends on biodiversity, so all four statements are correct.
- ✓ 1. Soil formation is a supporting ecosystem service. Plants, microbes and other soil organisms help turn parent rock and organic matter into soil, so biological activity is one of the basic soil-forming factors.
- ✓ 2. Erosion control is an ecosystem service of biodiversity. Roots and soil organisms bind soil particles into stable aggregates, which reduces erosion.
- ✓ 3. Soil organisms decompose litter and organic matter and cycle nutrients. This is natural recycling of organic waste, and FAO lists decomposition as a vital soil biodiversity function.
- ✓ 4. Pollination of crops is a standard ecosystem service. It is one of the indirect benefits people receive from biodiversity, along with pest control, climate moderation and flood control.
Remember · Biodiversity supports four kinds of ecosystem services: supporting (soil formation, nutrient cycling), regulating (erosion control, pollination, waste decomposition), provisioning and cultural. Each of the four items belongs to the first two kinds.
📘 Read it in NCERT: Class 12 Biology, Ch 13 (practise this chapter)
Sources
- FAO – Biodiversity and Ecosystem Services (Plant Production and Protection Division) ↗ “Supporting (e.g. soil formation, nutrient cycling , primary production) Provisioning (e.g. food, fresh water, fuelwood, fiber, biochemicals, genetic resources) Regulating (e.g. climate regulation, disease regulation, water regulation, water purification, pollination) … Diverse organisms contributing to soil biodiversity perform a number of vital functions that regulate the soil ecosystem, including: decomposition of litter and cycling of nutrients”
- FAO – Biodiversity for Food and Agriculture ↗ “Biodiversity exists in all land and water-related dimensions of agricultural activity, and also supplies ecosystem services such as oxygen production, erosion control and pollination.”
- NCERT Class 12 · Biology, Chapter 13 “there are many indirect benefits we receive through ecosystem services such as pollination, pest control, climate moderation and flood control.”
Question: UPSC Civil Services (Preliminary) 2011, General Studies paper. Explanation: Minimalist IAS, checked 25 Oct 2026 (how we verify). ·