Which of the following morphological features is shared by both a mature maize grain and a mature castor seed?

Step-by-step solution

Maize is a monocotyledonous plant and its grain is typically endospermic. Castor is a dicotyledonous plant, but unlike many dicots (such as pea or gram), it is an exception and has endospermic seeds. Therefore, the presence of a bulky endosperm is a feature shared by both mature maize and castor seeds. Maize has a single cotyledon (scutellum) and a fused seed coat and fruit wall, whereas castor has two cotyledons and a distinct seed coat. A coleoptile is found only in monocots like maize. Answer: Presence of a bulk