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Our Environment — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10ScienceOur Environment1 Mark
MCQ
For two statements are given $-$ one labelled Assertion $(A)$ and the other labelled Reason $(R).$ Select the correct answer to these questions from the codes $\ce{(a), (b), (c)}$ and $(d)$ as given below :
Assertion : A food chain can have a maximum of three trophic levels.
Reason : Energy available at each trophic level keeps on decreasing as we move higher up the food chain.
  • A
    Both $A$ and $R$ are true, and $R$ is correct explanation of the assertion.
  • B
    Both $A$ and $R$ are true, but $R$ is not the correct explanation of the assertion.
  • C
    $A$ is true, but $R$ is false.
  • ✓
    $A$ is false, but $R$ is true.
✓

Answer

Correct option: D.
$A$ is false, but $R$ is true.
A food chain can have a maximum of five to six trophic levels, this is because a lot of energy is lost as heat at each trophic level on account of metabolism. So, a small amount of energy becomes available to the next trophic level. This limits the number of trophic level in a food chain.

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