Question

Assertion: An increase in ozone concentration near the earth's surface reduces crop yields.

Reason: Increase in ozone concentration in the stratosphere protects us.

Read the assertion and reason statements carefully and answer the question on the basis of the following options.

• A. The assertion is true and the reason is also true; Reason is a correct explanation for Assertion.
• B. The assertion is true and the reason is also true; Reason is NOT a correct explanation for Assertion.
• C. The assertion is true but the reason is false.
• D. The assertion is false but the reason is true.

Answer 1

The correct option is B

The assertion is true and the reason is also true; Reason is NOT a correct explanation for Assertion.

The correct option is B.

Assertion statement:

1. Because ozone (O₃) molecules penetrate the plants by entering the stomata and cause obvious damage to the leaves and other components, thus, an increase in ozone concentration near the earth's surface affects crop production.
2. It has the potential to reduce the yield and quality of the leaves and other elements.
3. It may reduce agricultural productivity and quality.

So, the assertion is correct.

Reason statement:

1. However, a higher concentration of O₃ in the stratosphere protects humans from the sun's harmful UV rays.
2. The ozone layer blocks the entry of UV rays to the earth's surface.

So, the reason stated is correct.

Final Answer: (B) The assertion is true and the reason is also true; Reason is NOT a correct explanation for Assertion.