Identify the organism in which pyruvic acid gets converted to lactic acid in the absence of oxygen.

Options

A. Amoeba
B. Paramoecium
C. Fungus
D. Vertebrate animals

Explanation

**Step-by-Step Solution:**

1. **Understanding the Process**: The question asks about the conversion of pyruvic acid to lactic acid in the absence of oxygen. This process is known as fermentation, specifically lactic acid fermentation.

2. **Identifying the Conditions**: Lactic acid fermentation occurs under anaerobic conditions, meaning it takes place when oxygen is not present.

3. **Recognizing the Enzyme Involved**: The enzyme responsible for this conversion is called lactate dehydrogenase. This enzyme facilitates the transformation of pyruvic acid into lactic acid.

4. **Identifying the Organisms**:
- Lactic acid fermentation primarily occurs in muscle cells of animals, particularly during intense exercise when oxygen is scarce.
- Additionally, certain bacteria are known to perform this process, with the most notable being the fungus Lactobacillus.

5. **Conclusion**: Based on the information, the organism in which pyruvic acid gets converted to lactic acid in the absence of oxygen is Lactobacillus, a type of fungus.

**Final Answer**: The organism is Lactobacillus.

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