Bioaccumulation basic idea – UGC NET Question

Bioaccumulation occurs when a substance such as a heavy metal or persistent organic pollutant is taken up by an organism faster than it can be eliminated. Over time,its concentration in tissues increases,even if environmental levels remain low. The stem clearly describes this gradual build up,so bioaccumulation is the correct term.

Option A:
Bioaccumulation focuses on processes within an individual organism,highlighting uptake,storage and slow elimination. It helps explain why organisms can carry high internal loads of contaminants despite low external exposures. This explanation matches the description in the question.

Option B:
Biomagnification refers to increasing concentrations of a substance at successive trophic levels in a food chain. While it depends on bioaccumulation in organisms,it is a broader community level phenomenon,not the individual process emphasised in the stem.

Option C:
Biodegradation is the breakdown of substances by microorganisms into simpler compounds,often reducing toxicity. It is essentially the opposite of accumulation and therefore cannot fill the blank.

Option D:
Bioindicators are species or communities whose presence or condition reflects environmental quality. They may themselves accumulate pollutants,but the term describes their indicative role rather than the chemical accumulation process.