NEETBotanySexual Reproduction in Flowering Plants
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The primary endosperm nucleus (PEN) in angiosperms is triploid ( 3n ). Reason (R): PEN is formed by the process of triple fusion, where a haploid male gamete fuses with two haploid polar nuclei. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A).
- CAssertion (A) is true but Reason (R) is false.
- DAssertion (A) is false but Reason (R) is true.
Correct answer
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
The primary endosperm nucleus (PEN) in angiosperms is indeed triploid ( 3n ), making the Assertion true. This triploid nature is due to the event of triple fusion during double fertilization, where one haploid ( n ) male gamete fuses with two haploid ( n ) polar nuclei (or a diploid secondary nucleus) in the central cell. Thus, the Reason is also true and correctly explains why the PEN is triploid. Therefore, both Assertion and Reason are true, and the Reason correctly explains the Assertion. Answer: Both Assertion