Question

The endosperm nucleus gives rise to a number of free nuclei which remain in the peripheral layer of embryo sac, cytoplasm surrounding a large central vacuole in case of ...............

• A. Cocos
• B. Capsella bursa-pastoris
• C. Datepalm
• D. All of the above

Answer 1

The correct option is D All of the above

All of them have nuclear endosperm. The primary endosperm nucleus divides repeatedly without wall formation to produce a large number of free nuclei. Meanwhile, central vacuole appears in the central cell and pushes the cytoplasm containing the nuclei to the periphery. The cytoplasm thickens so that the vacuole decreases in size. It ultimately disappears with the exception of a few cases. The multinucleate cytoplasm undergoes cleavage and gives rise to a multicellular tissue, e.g., Maize, Wheat, Rice, Sunflower, Capsella bursa-pastoris. In several cases, the cell wall formation remains incomplete. For example, Coconut has multicellular endosperm (called coconut meal) in the outer part and free nuclear as well as vacuolated endosperm (called coconut milk) in the centre. In Pharsalus wall formation occurs around the embryo only while in Crotalaria it is restricted to the upper half. Nuclear endosperm is the most common type of endosperm. It is named so because it contains free nuclei in the beginning.