Select the wrongly matched option.

Options

A. (1) Nitrobacter - Chemoautotrph
B. (2) Anabaena - Autotroph
C. (3) Rhodospirillum - Symbiotic N2 -fixer
D. (4) Rhizobium - Heterotroph

Answer

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

### Step 1: Analyze the first option - Nitrovector
- **Definition**: Nitrovector is classified as a chemoautotroph.
- **Explanation**: Chemoautotrophs are organisms that can produce their own food using chemical compounds. This is a correct classification.
- **Conclusion**: This option is correctly matched.

### Step 2: Analyze the second option - Anavena
- **Definition**: Anavena is described as an autotroph.
- **Explanation**: Autotrophs are organisms that can synthesize their own food from inorganic substances. This classification is correct.
- **Conclusion**: This option is correctly matched.

### Step 3: Analyze the third option - Rhodospirillum
- **Definition**: Rhodospirillum is stated to be a symbiotic nitrogen fixer.
- **Explanation**: However, Rhodospirillum is actually a free-living nitrogen-fixing bacterium, not a symbiotic one. This means it does not form a symbiotic relationship with plants to fix nitrogen.
- **Conclusion**: This option is incorrectly matched.

### Step 4: Analyze the fourth option - Rhizobium
- **Definition**: Rhizobium is described as a heterotroph.
- **Explanation**: Rhizobium is actually a symbiotic nitrogen-fixing bacterium that forms a relationship with legumes, but it can also be classified as a heterotroph since it derives its nutrients from organic sources.
- **Conclusion**: This option is correctly matched.

### Final Conclusion:
The wrongly matched option is **Rhodospirillum**, which is incorrectly classified as a symbiotic nitrogen fixer.

---