Answer: Progressive increase in concentration of persistent pollutants (like DDT, mercury) at each trophic level in a food chain.
- A Magnification of bacterial colony growth as routinely observed under a standard laboratory light microscope setup
- B Progressive increase in concentration of persistent pollutants (like DDT, mercury) at each trophic level in a food chain
- C Abnormal growth patterns in organisms that are directly and visibly triggered by exposure to chemical pollutants over time
- D An overall increase in regional biodiversity that gradually follows a significant habitat disturbance event
Correct answer: B. Progressive increase in concentration of persistent pollutants (like DDT, mercury) at each trophic level in a food chain
Explanation: Biomagnification (bioaccumulation): fat-soluble persistent pollutants (DDT, PCBs, methylmercury) are not excreted and accumulate in body fat. At each trophic level, predators eat many prey, concentrating the pollutant. Top predators (eagles, tuna, humans) have the highest concentrations.
Sunlight passes through the atmosphere and warms the surface; the surface re-radiates this energy as infrared heat, which greenhouse gases (CO₂, CH₄, water vapour) absorb and trap - a naturally beneficial process that intensifies into global warming as gas concentrations rise from human activity.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.