Enzyme action comes to a stop when hydration decreases in maturing seeds to

Options

A. 50 - 60%
B. 30 - 45%
C. 25 - 30%
D. 10 - 20%

Answer

To solve the question regarding the cessation of enzyme action due to decreased hydration in maturing seeds, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Role of Water in Germination**:
- Water is crucial for the germination process of seeds. It activates enzymes that are necessary for metabolic processes.

2. **Impact of Dehydration**:
- As hydration decreases, the water content in seeds drops. This leads to a reduction in the activity of enzymes that facilitate growth and metabolism.

3. **Identifying the Critical Hydration Levels**:
- The question provides several hydration percentage options: 50-60%, 30-45%, 25-30%, and 10-20%. We need to determine at which hydration level enzyme action stops.

4. **Analyzing the Options**:
- As hydration decreases to lower levels, the seed's ability to sustain enzyme activity diminishes. The transcript indicates that enzyme action stops when hydration reaches a critical low.

5. **Determining the Correct Answer**:
- According to the information provided, enzyme action ceases when hydration levels drop to **10-20%**. This is the threshold at which the embryo inside the seed stops growing and may eventually die due to insufficient water.

6. **Final Conclusion**:
- Therefore, the correct answer to the question is **10-20%** (Option 4).