Question

Assertion :Pinus shows formation of annual rings Reason: Pinus grows in area of environmental fluctuation

• A. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
• B. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
• C. If the assertion is true but the reason is false
• D. If both the assertion and reason are false

Answer 1

The correct option is A If both the assertion and the reason are true and the reason is a correct explanation of the assertion

Secondary growth takes place in the manner similar to dicotyledonous stem. The secondary word shows well marked growth rings which are formed annually due to environmental fluctuations. Each annual ring possesses a zone of spring and an autumn wood. Spring wood is formed during season under availability of enough water and minerals. It possess large polygonal, thin walled and wide lumen with large bordered pits. Autumn wood is formed during Autumn season. It possesses smaller, thick walled and narrow centroids with small bordered pits. It is evident that the size of lumen shows a marked variation with regard to amount of nature available in the respective season.

So, the correct answer is 'If both the assertion and the reason are true and the reason is a correct explanation of the assertion'