Home
Class 11
BIOLOGY
Assertion. Sieve tube members have abund...

Assertion. Sieve tube members have abundant cytoplasm but there is no nucleus.
Reason. Nucleus is present in companion cell.

A

If both Assertion and Reason are true and the Reason is a correct explanation of the Assertion

B

If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion

C

If Assertion is true but the Reason is false

D

If both Assertion and Reason are false

Text Solution

AI Generated Solution

The correct Answer is:
To analyze the assertion and reason provided in the question, we can follow these steps: ### Step-by-Step Solution: 1. **Identify the Assertion**: The assertion states that "Sieve tube members have abundant cytoplasm but there is no nucleus." - **Explanation**: Sieve tube members are specialized cells in the phloem tissue responsible for the transport of nutrients, particularly sugars. They are characterized by having a significant amount of cytoplasm but lack a nucleus. 2. **Identify the Reason**: The reason states that "Nucleus is present in companion cells." - **Explanation**: Companion cells are closely associated with sieve tube members and play a crucial role in supporting them. Unlike sieve tube members, companion cells contain a nucleus, which is essential for their metabolic functions. 3. **Relationship Between Assertion and Reason**: - Both the assertion and the reason are true statements. However, the reason does not provide a direct explanation for the assertion. The presence of a nucleus in companion cells does not explain why sieve tube members lack a nucleus. 4. **Conclusion**: - Since both statements are true, but the reason does not justify the assertion, we conclude that the correct option is: "Both A and R are true but R is not the correct explanation of A." ### Final Answer: The correct option is: "Both A and R are true but R is not the correct explanation of A." ---
Promotional Banner

Topper's Solved these Questions

  • ANATOMY OF FLOWERING PLANTS

    PRADEEP|Exercise PRACTICE QUESTIONS (MULTIPLE CHOICE QUESTION)|83 Videos

  • ANIMAL KINGDOM

    PRADEEP|Exercise Assertion-Reason Type Questions|44 Videos

Similar Questions

Explore conceptually related problems

Sieve tubes have

[A]: Sieve tube members have abundant cy- toplasm but there is no nucleus. [R]: The nucleus disint~grates during their development

Assertion :- Sieve tube element and companion cell are called sister cells. Reason :- Sieve tube element and companion cells arise from same mother cells.

Cells must have a nucleus to live.

An oranised and differentiated cellular structure having cytoplasm but no nucleus is

Nucleus || Cytoplasm

Granulocytes have _______ cytoplasm and nucleus.

Identify the correct pair of statemetns. I. Functions of sieve tubes are controlled by the nucleus of companion cells. II. Albuminous cells are present in angiosperms. III. In dicot root, the vascular cambium is completely secondary in origin. IV. Cylindrical meristems contribute to the formation of primary plant body.

Sieve tubes differ from the sieve cells because they