Question

Assertion :Long distance flow of photo assimilates in plants occurs through sieve tubes. Reason: Mature sieve tubes have parietal cytoplasm and perforated sieve plates.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
• C. Assertion is correct but Reason is incorrect.
• D. If the assertion is false but the reason is true.

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.

In flowering plants, the sieve tube elements or sieve tube members, are a specialized elongated cell present in the phloem tissue that is responsible for transporting of carbohydrates from the leaves to the other parts of the plants.

Unlike the xylem vessels, these are living cells which lack nucleus at maturity. the sieve tube elements connect with each other at the ends to form the sieve tube. At the ends where the sieve tubes connect are present the perforated sieve plates with parietal cytoplasm that facilitates transport of materials.

So, the correct answer is option A.