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.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

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 : The magnetic field intensity at the center of a circular coil carrying current changes, if the current through the coil is doubled.
Reason : The magnetic field intensity is dependent on current in conductor.
Two statements are given $-$ one labelled
Assertion $(A)$ and the other labelled
Reason $(R)$. Select the correct answer to these questions from the codes $(a), (b), (c)$ and $(d)$ as given below:
Assertion $(A):$ In a homologous series of alcohols, the formula for the second member is $C _2 H _5 OH$ and the third member is $C _3 H _7 OH$.
Reason$(R):$ The difference between the molecular masses of the two consecutive members of a homologous series is $144 .$
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 : The reaction of calcium with water is less violent in comparison to that of sodium.
Reason : The heat evolved is not sufficient for the hydrogen to catch fire.
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 : The testes are present outside the abdominal cavity of the body.
Reason : Sperm formation requires a lower temperature than the normal body temperature.
For question 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 : Carbon and its compounds can be used as fuels.
Reason : They are highly inflammable and have high calorific value.
For question 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 : Antacids neutralize the effect of extra acid produced in the stomach during indigestion and thus provide relief.
Reason : Antacids are mild bases.
Assertion (A): On adding dil. HCI to a test tube containing a substance 'X', a colourless gas is produced which gives a pop sound when a burning match stick is brought near it.
Reason (R): In this reaction metal 'X' is displaced by Hydrogen.
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 : Magnesium reacts with oxygen upon heating and burns brightly to form magnesium oxide.
Reason : Magnesium oxide is basic in nature.
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 : In the case of concave mirror, the minimum distance between real object and its real image is zero.
Reason : If concave mirror forms virtual image of real object, the image is magnified.
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 : All the sepals together are called corolla.
Reason : The function of sepals is to protect the flower in the bud stage.