Concept: This question tests your understanding of the structure of dicotyledonous seeds, focusing on key anatomical features and the presence or absence of endosperm.

Why (C) is incorrect: Castor (Ricinus communis) is a classic example of an endospermic (albuminous) dicot seed. This means that the endosperm persists and stores food, providing nourishment to the developing embryo. Therefore, stating it is non-endospermic is incorrect.

Why other options are correct:

• (A) Above the hilum is a small pore called the micropyle: This is correct. The hilum is a scar on the seed coat where the developing seeds were attached to the fruit, and the micropyle is a small pore above it, facilitating water absorption.
• (B) Within the seed coat is the embryo, consisting of an embryonal axis and two cotyledons: This accurately describes the internal structure of a dicot embryo.
• (D) At the two ends of embryonal axis are present the radicle and plumule: This is correct. The radicle develops into the root system, and the plumule develops into the shoot system.

Common Mistake: Students often confuse endospermic and non-endospermic seeds, especially for specific examples like castor (endospermic) and pea/bean (non-endospermic).

NEET Tip / Mnemonic: Remember that most dicots are non-endospermic (e.g., pea, bean, gram), but some important exceptions like Castor are endospermic. For monocots, most are endospermic (e.g., maize, wheat), but orchids are non-endospermic.

Correct Answer: (C)