Question 31 markVery Short AnswerSection A

$What will happen if we kill all the organisms in one trophic level?$

Q: What will happen if we kill all the organisms in one trophic level?

If we kill all the organisms in one trophic level, the transfer of food and energy to the next higher trophic level will stop, causing those organisms to starve and die. At the same time, the population of organisms in the lower trophic level will increase uncontrollably due to the absence of predators. This will severely disrupt the ecological balance of the entire ecosystem.

Our Environment

Food Chains and Webs

Official answer

If we kill all the organisms in one trophic level, the transfer of food and energy to the next higher trophic level will stop, causing those organisms to starve and die. At the same time, the population of organisms in the lower trophic level will increase uncontrollably due to the absence of predators. This will severely disrupt the ecological balance of the entire ecosystem.

disrupt energy flow

starvation

population increase

ecological imbalance

trophic level

Marking scheme

1. $0.5 marks for stating that the next higher trophic level will starve/die due to lack of food/energy flow.$
2. $0.5 marks for stating that the lower trophic level population will increase uncontrollably, disrupting the ecological balance.$

Hint

$Think about what happens to the organisms that eat them (above them in the food chain) and the organisms they eat (below them in the food chain).$

Quick oral answer

$If all organisms in one trophic level are killed, the food chain is broken. The organisms at the next higher level will starve and die due to lack of food, while the population of organisms at the lower level will grow exponentially because there are no predators to keep them in check. This disrupts the entire ecological balance.$

Common mistakes

1. $Only mentioning the effect on the higher trophic level (starvation) while completely forgetting the population explosion at the lower trophic level.$

Analysis and explanation

In a food chain, energy flows unidirectionally from lower trophic levels to higher trophic levels. Each level is dependent on the preceding one for energy. If an entire trophic level is eliminated: The higher trophic level (predators/consumers) will face an acute shortage of food, leading to starvation and a decline in their population. The lower trophic level (prey/producers) will experience a population explosion because their natural predators have been removed. This overpopulation can lead to over-exploitation of resources (e.g., overgrazing by herbivores), ultimately collapsing the ecosystem.

Interesting facts

$In ecology, this dramatic disruption caused by removing a trophic level (especially top predators) is known as a 'trophic cascade', which can completely transform landscapes.$

Question details

Q3 of 36 questions

Board: CBSE
Class: Class 10
Subject: Science
Year: 2011
Section: Section A
Marks: 1
Type: Very Short Answer
Chapter: Our Environment
Topic: $Food Chains and Webs$
Bloom's level: Understanding
Syllabus topic: $Ecosystem, Environmental problems, Ozone depletion, waste production and their solutions. Biodegradable and non-biodegradable substances.$

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Frequently asked questions

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

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

$Which chapter does this question come from in Science?$

$This question is from the chapter "Our Environment" in the CBSE Class 10 Science syllabus.$

$What topic does this question cover in Science?$

$This question covers the topic "Food Chains and Webs" from CBSE Class 10 Science.$

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

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