Question

(A) Plants → Deer → Lion
In the given food chain, what will be the impact of removing all the organisms of second trophic level on the first and third trophic level?
Will the impact be the same for the organisms of the third trophic level in the above food chain if they were present in a food web? Justify.
OR
(B) A gas ‘X’ which is a deadly poison is found at the higher levels of atmosphere and performs an essential function.
Name the gas and write the function performed by this gas in the atmosphere. Which chemical is linked to the decrease in the level of this gas? What measures have been taken by an international organization to check the depletion of the layer containing this gas?

Answer 1

(A). Food Chain: Plants → Deer → Lion.
- The second trophic level (deer) is the primary consumer.
Impact:
• On the first trophic level (plants): Their population will increase due to reduced grazing pressure.
• On the third trophic level (lion): Their population will decline due to the absence of food.
In a food web, the impact on the third trophic level may be less severe because the lion can depend on other prey as a food source.

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(B). Gas ‘X’ is ozone.
- Function: It protects life on Earth by absorbing harmful ultraviolet (UV) radiation.
- Chemical causing depletion: Chlorofluorocarbons (CFCs).
- Measures: The Montreal Protocol was adopted to phase out the production and use of ozone-depleting substances like CFCs.