Dicot Seed Nutrition Explained

The question asks about the part of a dicot seed that provides nutrition to the growing seedling. Let's look at the functions of the parts mentioned in the options.

• Plumule: The plumule is a part of the embryo located at the apex of the embryonic axis. It develops into the shoot of the plant, which includes the stem and leaves. While essential for the seedling's growth, the plumule itself does not store or provide the primary nutrition.
• Micropyle: The micropyle is a small pore in the seed coat through which water usually enters the seed during germination. It facilitates germination but is not a source of stored food or nutrition for the growing seedling.
• Aleurone layer: The aleurone layer is typically a protein-rich layer found in the seeds of some plants, especially monocots like maize, wheat, and barley. In monocots, it surrounds the endosperm and plays a role in releasing enzymes that break down the stored food in the endosperm during germination. While it is nutritional and enzymatic in monocots, it is often absent or less prominent and not the primary source of nutrition storage in most dicots.

In most dicot seeds, the main source of stored food that provides nutrition for the growing seedling is the cotyledons. The cotyledons are embryonic leaves that absorb and store food reserves (like carbohydrates, proteins, and fats) from the endosperm during seed development. Upon germination, these stored food reserves are utilized by the developing plumule (shoot) and radicle (root).

Since the options provided (plumule, micropyle, aleurone layer) are not the primary parts of a dicot seed responsible for storing and providing nutrition to the growing seedling (that role belongs to the cotyledons), the correct answer is "None of the above".