Science (086) — AI-generated practice question

Biological Magnification: The progressive increase in the concentration of harmful chemicals (like pesticides) at each successive trophic level of a food chain is called biological magnification.

Example:
$$\text{Plants} \rightarrow \text{Insects (herbivore)} \rightarrow \text{Frog} \rightarrow \text{Snake} \rightarrow \text{Eagle (carnivore)}$$

Pesticides are absorbed by plants from soil/water. Since these chemicals are non-degradable, they are not broken down and keep accumulating in the body of each organism. A herbivore eats many plants, collecting all their pesticide content. The top carnivore then eats many herbivores and intermediate consumers, so the chemicals concentrate further at each level. Thus, the top carnivore accumulates the maximum concentration of pesticides.

Source: Chapter 13, Section 13.1.1 – Food Chains and Webs

---

• 1 mark for defining biological magnification correctly.
• 1 mark for a valid food chain with labels.
• 1 mark for the explanation of why concentration increases — key idea is that chemicals are non-degradable and each consumer eats many organisms from the level below, so chemicals keep accumulating upward.
• Do not just say "carnivores eat more" — you must link it to the non-degradable nature of chemicals and their progressive accumulation at each trophic level.