______ can live in the marshy area and in cattle rumen.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Environment**: The question asks about organisms that can live in marshy areas and in the rumen of cattle. Marshy areas are wetlands that are often anaerobic (low in oxygen).

2. **Identifying Key Processes**: In these environments, a significant biological process occurs called methanogenesis, which is the production of methane gas. This process is crucial in both marshy areas and the digestive systems of ruminants.

3. **Recognizing the Organisms Involved**: The organisms responsible for methanogenesis are known as methanogens. These are a specific group of archaea that thrive in anaerobic conditions and are capable of producing methane.

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