Question

Two statements are given – one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer from the codes given below:
Assertion (A): Contact inhibition is absent in cancer cells.
Reason (R): Normal cells stop growing when they reach the walls of the container.

• A. Both Assertion (A) and Reason (R) are true and the Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but the Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

Contact inhibition prevents normal cells from overgrowing; cancer cells lose this control and keep dividing.

Answer 1

The Correct Option is B

Contact inhibition is a process where normal cells stop dividing once they form a single layer by contacting each other. Cancer cells lack this property and continue to divide uncontrollably.

• Assertion (A): True. Cancer cells do not exhibit contact inhibition.
• Reason (R): True. Normal cells stop growing when they come in contact with the container walls or other cells.
• However, the Reason does not explain the absence of contact inhibition in cancer cells, so option (B) is correct.