Question

Assertion: Ex-albuminous seeds do not possess any residual endosperm, as it is completely consumed during embryo development.
Reason: Wheat, castor, pea and groundnut are all the examples of ex-albuminous seeds.
A. Both Assertion and Reason are correct and Reason is the correct explanation for the Assertion.
B. Both Assertion and Reason are correct and Reason is not the correct explanation for the Assertion.
C. Assertion is correct but Reason is incorrect.
D. Both Assertion and Reason are incorrect.

Answer 1

Endosperm is formed during triple fusion in angiosperms. Triple fusion involves both syngamy and double fertilization and it was discovered by Strasburger. The nucleus of one of the male gametes fuses with the two polar nuclei present in the central cell and this results in the formation of triploid primary endosperm nucleus.

Complete answer: Seeds are divided into endospermic and non-endospermic based on the presence or absence of the endosperm respectively. The seeds of the papaya, castor, sunflower, rubber, cotton and custard apple are endospermic while most of the dicot seeds are non-endospermic.
The monocotyledonous seeds are with a single cotyledon and are generally endospermic.
So the assertion that ex- albuminous or non-albuminous seeds do not possess any residual endosperm because it is completely consumed is true. But the reason statement is wrong as wheat, castor, pea and groundnut are all examples of albuminous seeds.
So, the correct answer is “Option C”.

Additional Information: The types of endosperms found in plants are:
Nuclear endosperm- It is the type of endosperm in which the primary endosperm nucleus divides and redivides but it is not followed by cytokinesis.
Cellular endosperm- In this, the wall formation occurs after every division of primary endosperm nucleus so that it is of cellular form from the beginning.
Helobial endosperm- In this, the first division of primary endosperm nucleus is followed by cytokinesis to produce two unequal sizes of cells.

Note: The endospore formation, embryo formation, seed formation, and fruit formation are the post-fertilization changes in the plants. The endosperm development precedes the embryo development to ensure the proper supply of nutrition to the developing embryo.