Which one of the following pairs is wrongly matched ?

Options

A. Nitrosomonas : Nitrifying and chemo lithotrophic bacteria .
B. Rhodospirillum : Nitrogen fixation bacteria and photo - organotrophs bacteria.
C. E coli : used in genetic engineering and pollution indicating bacteria
D. Pseudomonas : responsible for food poisoning and purity of Ganga water.

Answer

To solve the question of which pair is wrongly matched, we will analyze each option provided in the question step by step.

### Step 1: Analyze the first pair - Nitrosomonas
- **Bacteria**: Nitrosomonas
- **Function**: Nitrifying and chemolithotrophic bacteria
- **Analysis**: Nitrosomonas is indeed a nitrifying bacterium that converts ammonia into nitrites, and it is also classified as a chemolithotroph because it derives energy from inorganic compounds.
- **Conclusion**: This pair is correctly matched.

### Step 2: Analyze the second pair - Rhodospirillum
- **Bacteria**: Rhodospirillum
- **Function**: Nitrogen fixation and photo-organotroph
- **Analysis**: Rhodospirillum is known for its ability to fix nitrogen and is classified as a photo-organotroph, as it can utilize light for energy while also using organic compounds.
- **Conclusion**: This pair is correctly matched.

### Step 3: Analyze the third pair - E. coli
- **Bacteria**: E. coli (Escherichia coli)
- **Function**: Used in genetic engineering and pollution indicating bacteria
- **Analysis**: E. coli is widely used in genetic engineering as a vector for cloning and is also used as an indicator organism for water quality, indicating fecal contamination.
- **Conclusion**: This pair is correctly matched.

### Step 4: Analyze the fourth pair - Pseudomonas
- **Bacteria**: Pseudomonas
- **Function**: Responsible for food poisoning and the purity of Ganga water
- **Analysis**: While some species of Pseudomonas can cause food poisoning, the purity of Ganga water is typically associated with coliform bacteria, not specifically Pseudomonas. Therefore, this pair is incorrectly matched.
- **Conclusion**: This pair is wrongly matched.

### Final Answer
The wrongly matched pair is **Pseudomonas** responsible for food poisoning and the purity of Ganga water.

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