Assertion (A): Food web is a network of several food chains operating in an ecosystem.
Reason (R): Food web decreases the stability of an ecosystem.
Assertion (A) is false, but Reason (R) is true.
Step 1: Understanding Food Web. A food web is a network of interconnected food chains within an ecosystem, illustrating how different species are related through feeding.
Step 2: Analyzing Reason (R). Food webs actually increase the stability of an ecosystem by providing alternative pathways for energy flow, meaning that if one species declines, others can take its place.
Step 3: Conclusion. Since Assertion (A) is true but Reason (R) is false, the correct answer is option (C).
| Case No. | Lens | Focal Length | Object Distance |
|---|---|---|---|
| 1 | \(A\) | 50 cm | 25 cm |
| 2 | B | 20 cm | 60 cm |
| 3 | C | 15 cm | 30 cm |
Consider the following food chain: Grass → Grasshopper → Frog → Snake → Eagle If the amount of energy available at third trophic level is 50 kJ, the available energy at the producer level was:
| Case No. | Lens | Focal Length | Object Distance |
|---|---|---|---|
| 1 | \(A\) | 50 cm | 25 cm |
| 2 | B | 20 cm | 60 cm |
| 3 | C | 15 cm | 30 cm |