Question

In the given food web, an insecticide is sprayed to kill the caterpillars. In which organisms will the highest level of insecticide accumulate after a period of time?

A) Foxes
B) Hawks
C) Mice
D) Sparrows

Answer 1

Hint: Biological magnification refers to the process in which transfer of harmful chemicals increases with the increasing trophic level. Biomagnification is the building up of toxins in a food chain. As the trophic level moves up in its order, the amount of toxic build up also increases.

Complete answer:
-The grains, hogweed, china rose are the producers. The insecticides sprayed enter the food chain through them.
-The second trophic level is being occupied by rabbits, mice, goldfinches, aphids and caterpillars. They are eaten up by the organism of third trophic level foxes and sparrows.
-Highest accumulation of insecticide could be found in hawks as it is at the highest point of the food web. It will clearly arrive at all different living beings in the food web, yet the most extreme is found in hawks.

Additional Information:
Biomagnification or bioamplification takes place due to
-Persistence – where the substance can't be separated by natural cycles.
-Food chain energetics – where the substances focus increments dynamically as it climbs a food web.
-Low or non-existent rate of internal degradation or discharge of the substance – basically because of water-insolubility.
Hence the correct answer is option ‘A’.

Note: The substances become progressively gathered in tissues or inside organs as they climb the chain. Bioaccumulation are substances that increase in concentration in organisms as they take in polluted air, water, or food because the substances are very slowly metabolized or excreted.