In a plant cell, starch acts as a ..................... unit, while cellulose acts as a ..................... unit.

Explanation

To answer the question: "In a plant cell, starch acts as a ..................... unit, while cellulose acts as a ..................... unit," we need to understand the roles of starch and cellulose in plant cells.

### Step-by-Step Solution:

1. **Identify the Role of Starch:**
- Starch is a polysaccharide that serves as a storage form of energy in plants. It is produced during photosynthesis and stored in various cell organelles. When the plant requires energy, it breaks down starch into glucose, which can be utilized for metabolic functions.
- **Conclusion:** Starch acts as a **functional unit** because it is involved in the energy metabolism of the plant.

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