Enter OTP to View Content

Double Fertilization – Assertion & Reason

Assertion & Reason – Double Fertilization

Assertion (A): Double fertilization is an event unique to flowering plants.

Reason (R): Since two types of fusions, syngamy and triple fusion, take place in an embryo sac, the phenomenon is termed double fertilization.

Choose the correct answer:

(1) Both Assertion & Reason are True, and the Reason is a correct explanation of the Assertion.
(2) Both Assertion & Reason are True, but the Reason is not a correct explanation of the Assertion.
(3) Assertion is True, but the Reason is False.
(4) Both Assertion & Reason are False.

Correct Answer: (2) Both Assertion & Reason are True, but the Reason is not a correct explanation of the Assertion.

Explanation:

✔ Assertion is True: Double fertilization is found only in angiosperms and not in any other plant group.

✔ Reason is also True: The process involves two fusions—syngamy (formation of the zygote) and triple fusion (formation of the triploid endosperm).

❌ But the Reason does not correctly explain why double fertilization is unique to angiosperms. It only describes the process, without mentioning the key evolutionary advantage—**efficient resource utilization and enhanced embryo nourishment, which contributes to the reproductive success of angiosperms.**

Double Fertilization in Angiosperms

Double fertilization is a unique evolutionary adaptation in angiosperms because it enhances reproductive efficiency and ensures optimal resource allocation. This process involves the fusion of one male gamete with the egg cell (forming the zygote, which develops into the embryo) and the other male gamete with the central cell (forming the triploid endosperm, which provides nourishment to the developing embryo).

Reasons for Evolutionary Significance:

Efficient Resource Utilization: The endosperm is formed only if fertilization occurs, preventing wastage of nutrients that would otherwise be used for unsuccessful ovules.
Enhanced Seed Viability: The triploid endosperm provides ample stored food, ensuring better nourishment for the developing embryo compared to the haploid or diploid nutritive tissues found in other plant groups.
Faster Development & Germination: Seeds of angiosperms develop quickly due to the immediate formation of the nourishing endosperm, providing an advantage over gymnosperms, where the female gametophyte takes longer to accumulate food reserves.