WHAT IS THE DIFFERENCE BETWEEN EPICOTYL, COLEOPTILE, PLUMULE AND SHOOT?

The portion of the embryonal axis above the level of cotyledons is called epicotyl. It contains the plumule (shoot tip) which develops into shoot during growh and development of plants.

In the grasses, which are monocotyledons, the plumule is protected by a sheath called coleoptile which is positively phototropic and negatively geotropic.