Q3
1 markVery Short AnswerSection A

What is meant by biological magnification ?

Chemical Reactions and Equations
Our Environment
Official Answer

Biological magnification refers to the process by which the concentration of non-biodegradable harmful chemicals (such as pesticides) increases progressively at each successive trophic level of a food chain.

Biological magnificationNon-biodegradableTrophic levelConcentration increasePesticides

Marking Scheme

  • 11 mark for defining it as the increase in concentration of chemicals at higher trophic levels.

Hint

Focus on how the amount of toxins changes as you move from plants to herbivores to carnivores.

Quick Oral Answer

It is the increase in the concentration of harmful, non-biodegradable substances like pesticides as we move up the food chain.

Analysis & Explanation

Since these chemicals are not degradable, they get accumulated at each trophic level. As human beings occupy the top level in many food chains, the maximum concentration of these chemicals is often found in our bodies.

Common Mistakes

  1. 1Confusing biological magnification with accumulation in a single organism (bioaccumulation).
  2. 2Thinking the concentration decreases as it moves up the food chain.

Interesting Facts

DDT is a famous example of a pesticide that caused biological magnification, leading to the thinning of eggshells in birds of prey like eagles.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2011?

This question carries 1 mark in the CBSE Class 10 Science 2011 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Chemical Reactions and Equations" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Our Environment" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2011 paper?

This is a Very Short Answer question from Section A in the CBSE Class 10 Science 2011 paper.