In some seeds, the seed coat barrier can be broken by

Options

A. Vigorous shaking
B. Microbial action
C. Nitrates
D. All of these

Answer

To answer the question "In some seeds, the seed coat barrier can be broken by?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Seed Coat**: The seed coat is a protective layer that surrounds the seed. It serves to protect the seed from physical damage and desiccation, but it can also inhibit germination.

2. **Identifying Methods to Break the Seed Coat**:
- **Vigorous Shaking**: This method can create abrasions on the seed coat, potentially allowing water and gases to penetrate and initiate germination.
- **Microbial Action**: Certain microorganisms can decompose the seed coat. This natural process can help in breaking down the seed coat, allowing the seed to germinate.
- **Nitrates**: Chemicals such as nitrates can also be used to weaken or break down the seed coat, facilitating germination.

3. **Evaluating the Options**: The question provides multiple options:
- Option 1: Vigorous shaking
- Option 2: Microbial action
- Option 3: Nitrates
- Option 4: All of these

4. **Conclusion**: Since all the mentioned methods (vigorous shaking, microbial action, and nitrates) can contribute to breaking the seed coat barrier, the correct answer is option 4: "All of these".

### Final Answer:
The seed coat barrier in some seeds can be broken by **all of these methods**: vigorous shaking, microbial action, and nitrates.

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