Biomagnification - Unsolved Practice Set
Chapter: Ecosystem | Topic: Biomagnification
BIOMAGNIFICATION - UNSOLVED PRACTICE SET
Topic: Biomagnification
Multiple Choice Questions
Q1. Biomagnification refers to the phenomenon in which:
- The concentration of a harmless, biodegradable substance decreases at each successive trophic level
- The concentration of a toxic, non-biodegradable substance increases at each successive trophic level in a food chain
- Energy increases at each trophic level
- Nutrient cycling speeds up over time
Q2. A classic historical example of biomagnification involves the accumulation of the pesticide:
- Penicillin
- DDT, in aquatic food chains
- Insulin
- Vitamin C
Q3. Biomagnification of DDT in certain bird species, such as eagles, was found to cause:
- Improved reproductive success
- Thinning of eggshells, negatively affecting reproduction
- No measurable biological effect
- Increased resistance to all toxins
Q4. Biomagnification occurs primarily because certain toxic substances are:
- Rapidly broken down and excreted by organisms
- Non-biodegradable (or slowly degradable) and tend to accumulate in an organism's tissues over time
- Completely harmless at any concentration
- Found only in producers, never in consumers
Q5. In a typical case of biomagnification, which trophic level generally shows the highest concentration of the toxic substance?
- Producers
- Primary consumers
- Top (apex) predators/consumers
- Decomposers only
Short Answer Questions
Q6. Define biomagnification, in your own words.
Q7. Give one historical example of biomagnification and briefly describe its ecological impact.
Q8. Why does the concentration of a biomagnified substance tend to be highest at the top of a food chain?
Q9. Why are non-biodegradable substances particularly prone to causing biomagnification, compared to easily degradable substances?
Long Answer Questions
Q10. Explain the phenomenon of biomagnification in detail, using the example of DDT accumulation in an aquatic food chain to describe how concentration increases at each trophic level.
Q11. Discuss the ecological and health significance of biomagnification, explaining why top predators (including humans, in some food chains) are particularly vulnerable to its effects.
APPLICATION / ANALYSIS
Q12. A pesticide used in a farming region is found in very low concentrations in pond water, moderate concentrations in small fish that live in the pond, and very high concentrations in the fish-eating birds at the top of the food chain. Explain, using your understanding of biomagnification, why the concentration increases so dramatically as you move up this food chain.
Q13. Following the widespread historical use of DDT, several bird-of-prey populations, including eagles, experienced sharp declines due to reproductive failure linked to eggshell thinning. Explain, using your understanding of biomagnification, why top predators like eagles were particularly severely affected compared to species lower in the food chain.