Which of the following organisms are expected to show the highest concentration of ddt and other chlorinated hydrocarbons in its tissues? a. phytoplankton b. sea lions c. zooplankton d. filter-feeding fishes

The correct answer is B. Sea lions

Explanation:

DDT is a chlorinated hydrocarbon that was used in the past as a pesticide and insecticide, this used was banned due to DDT toxicity. However, DDT can still be found in the tissues of many animals. In the case of marine ecosystem organisms with the highest concentration of DDT and similar substances are those found in the top of food chains including sea lions.

This occurs because DDT and similar accumulate in the water due to runoff and in there it is first absorbed by small organism such as phytoplankton, then these substances pass to primary consumers, secondary consumers, etc. until it reaches top predators such as sea lions in which DDT and other substances are major as contaminants increase during the food chain, this process is known as bioaccumulation.

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.