Question

1. an environmental scientist is studying the concentration of the pesticide ddt in a lake ecosystem. she finds that small amounts are present in the water, larger amounts in small fish, and even greater concentrations in fish - eating birds at the top of the food chain. this pattern results from toxins increasing as they move up each trophic level. what does this observation show about ddt and other persistent pollutants?

higher trophic level organisms can concentrate toxins in a type of \inverse biological pyramid.\
water - soluble toxins are widespread
ddt is easily metabolized and excreted by most organisms
ddt is an extremely water - soluble material

Explanation:

DDT is a persistent pollutant. In a food chain, as toxins move up each trophic level, their concentration increases. This is known as biomagnification. Higher trophic - level organisms (like fish - eating birds) have higher concentrations of DDT compared to lower - level organisms (like small fish and water). DDT is not easily metabolized or excreted by most organisms, and it is not extremely water - soluble. Water - soluble toxins would not biomagnify in the same way as they would be more likely to be excreted. The "inverse biological pyramid" is not the correct term for this phenomenon (the correct term is biomagnification).

Answer:

Higher trophic level organisms can concentrate toxins in a type of "inverse biological pyramid."