Previous Year Question
Given below are two statements, one is labelled as Assertion (A) and other as Reason (R):
Assertion (A): Various components of an ecosystem are not interdependent.
Reason (R): Human activities have impacts on the environment.
Select the correct answer using the codes given below:
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true, but (R) is not the correct explanation of (A).
(A) is true, but (R) is false.
(A) is false, but (R) is true.
Correct Answer: D
Detailed Solution
Assertion (A) is false. An Ecosystem is a functional unit in which Biotic and Abiotic components are interconnected and interdependent. Biotic components include Producers, Consumers, and Decomposers, while Abiotic components include sunlight, water, air, soil, temperature, and minerals. Interactions among these components play important roles in maintaining Energy Flow, Nutrient Cycling, and Ecological Balance.
Interdependence can be understood through a Food Chain. Green plants produce food through Photosynthesis, herbivores obtain energy from plants, and carnivores depend on other animals for food. Bacteria and fungi decompose dead organisms and organic remains, returning nutrients to the soil and environment. For example, in the food chain Grass → Deer → Tiger, a decline in grass availability may affect the deer population and subsequently reduce food availability for tigers.
Reason (R) is true. Human Activities influence both the Biotic and Abiotic components of the environment. Deforestation, Industrialization, Urbanization, pollution, and fossil fuel combustion can alter natural habitats, climate, and biodiversity. For example, deforestation destroys wildlife habitats, may increase Soil Erosion, and can affect the local Water Cycle. The IPBES Global Assessment Report (2019) identified land-use change, direct exploitation of organisms, climate change, and pollution among the major drivers of changes in nature.
The distinction between the Assertion and Reason is that the Assertion concerns the interdependence of ecosystem components, whereas the Reason describes the environmental impacts of human activities. A change in one ecosystem component can influence others because they are interconnected through Food Webs, Energy Flow, and Nutrient Cycles. Human activities such as Afforestation, Habitat Restoration, and pollution control can also contribute to environmental conservation. Thus, the Assertion is false, while the Reason is true.