Hirudin is

Options

A. a protein produced by Hordeum vulgare, which is rich in lysine
B. a toxic molecule isolated from Gossypium hirsutum, which reduces humn fertility
C. a protein produced from transgenic Brassica napus which prevents blood clotting
D. an antibiotic produced by a genetically engineered bacterium Escherichia coli

Explanation

### Step-by-Step Solution:

1. **Understanding Hirudin**: Hirudin is a protein that plays a crucial role in the prevention of blood clotting. It is important to recognize its biological function.

2. **Source of Hirudin**: This protein is derived from a genetically modified organism, specifically the plant known as Brassica napus. It is essential to identify the source of Hirudin for a complete understanding.

3. **Extraction Process**: Hirudin is extracted from the seeds of Brassica napus. After extraction, it undergoes a purification process to ensure it is suitable for medicinal use.

4. **Application in Medicine**: Hirudin is used in various medical applications, particularly in anticoagulant therapies, which help prevent blood clots in patients.

5. **Evaluating Options**: When presented with multiple-choice options regarding Hirudin, the correct answer is that it is a protein produced from transgenic Brassica napus.

### Final Answer:
Hirudin is a protein that is produced from the transgenic plant Brassica napus, and it is known for its ability to prevent blood clotting.

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