Stains used for lowering blood cholesterol level are extracted from

Options

A. algae
B. bacteria
C. viruses
D. yeast

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the source of strains used for lowering blood cholesterol levels. Specifically, it is looking for the organism from which these strains are extracted.

2. **Identifying the Product**: The strains in question are known as statins, which are compounds that help lower cholesterol levels in the blood.

3. **Source of Statins**: Statins are products of fermentation. The specific organism from which statins are derived is a type of yeast.

4. **Naming the Yeast**: The yeast that is primarily used for the production of statins is called *Monascus purpureus*. This yeast is known for its ability to produce compounds that inhibit cholesterol synthesis.

5. **Mechanism of Action**: Statins work by inhibiting the enzyme HMG-CoA reductase, which is crucial in the biosynthesis of cholesterol. By inhibiting this enzyme, statins effectively lower the production of cholesterol in the body.

6. **Examples of Statins**: Some common examples of statins include lovastatin, pravastatin, and simvastatin. These are used clinically to manage cholesterol levels.

7. **Final Answer**: Therefore, the strains used for lowering blood cholesterol levels are extracted from the yeast *Monascus purpureus*.

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