Practise original CBSE Class 10 Science competency based questions across all 13 chapters, with MCQs, assertion-reason, case studies, answers and worked solutions for Physics, Chemistry and Biology.
Question 1MCQ · Analyse · 1 mark
Our Environment · Food chains and energy flow
Grass stores 10,000 J of energy. In the chain grass → grasshopper → frog, apply the approximate 10% energy-transfer model. How much reaches the frog?
A persistent, non-biodegradable pesticide enters the chain phytoplankton → small fish → large fish → fish-eating bird. Where is its concentration expected to be greatest?
