Primary roots develop from the .........

Explanation

**Step-by-Step Solution:**

1. **Understanding Seed Structure**: To answer the question about where primary roots develop from, we first need to understand the structure of a seed, particularly in monocots. A monocot seed contains several key parts, including the endosperm, coleoptile, primule, radical, and coleorhiza.

2. **Identifying the Relevant Structures**: Among these structures, the radical is specifically responsible for root development. The coleorhiza also plays a role in guiding the roots below the ground, but it is the radical that gives rise to the primary roots.

3. **Defining the Role of the Radical**: The radical is the part of the seed that will grow into the primary root. As the seed germinates, the radical emerges and begins to grow downward into the soil, establishing the root system of the plant.

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