Bacteria living in human large intestine feeding on undigested food without harming the host show :

Options

A. Predators
B. Commensals
C. Symbionts
D. Parasities

Answer

To solve the question regarding the type of relationship that bacteria living in the human large intestine exhibit while feeding on undigested food without harming the host, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Relationship**: The question describes bacteria that live in the human large intestine and feed on undigested food without harming the host. This indicates a specific type of interaction between the bacteria and the human host.

2. **Understand the Options**: The options provided are:
- Option 1: Predators
- Option 2: Commensals
- Option 3: Symbionts
- Option 4: Parasites

3. **Analyze Each Option**:
- **Predators**: This type of interaction is characterized by one organism benefiting at the expense of another (plus/minus interaction). Predators kill their prey to obtain food, which does not apply here.
- **Commensals**: This interaction is where one organism benefits while the other is neither helped nor harmed (plus/zero interaction). This fits the description of the bacteria in the large intestine.
- **Symbionts**: In this relationship, both organisms benefit from each other (plus/plus interaction). This does not apply since the host is not benefiting from the bacteria feeding on undigested food.
- **Parasites**: This relationship is where one organism benefits at the expense of the other (plus/minus interaction). Parasites harm their host, which is not the case here.

4. **Select the Correct Option**: Based on the analysis, the correct answer is **Option 2: Commensals**. These bacteria are commensal organisms that benefit from the undigested food without harming the human host.

### Final Answer:
The bacteria living in the human large intestine feeding on undigested food without harming the host show **commensalism** (Option 2: Commensals).

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