A mutant micro-organism unable to synthesize a compound required for it growth but able to grow if the compound is provided, is known as

Options

A. Auxotropy
B. Prototropy
C. Autotropy
D. None of these

Answer

To solve the question regarding the classification of a mutant microorganism that cannot synthesize a compound necessary for its growth but can grow if the compound is supplied, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terminology**:
- The question describes a microorganism that is unable to synthesize a necessary compound for its growth. This indicates that it has a mutation affecting its metabolic capabilities.

2. **Identifying Types of Microorganisms**:
- In microbiology, organisms can be classified based on their ability to synthesize certain compounds.
- **Prototrophs** are organisms that can synthesize all the compounds they need for growth from minimal media.
- **Auxotrophs**, on the other hand, are mutants that cannot synthesize one or more compounds required for their growth and need these compounds to be supplied in their growth medium.

3. **Relating to Beadle and Tatum's Work**:
- The concept of prototrophs and auxotrophs was established through the work of scientists George Beadle and Edward Tatum. They conducted experiments with the fungus *Neurospora crassa*.
- They found that while the wild-type (normal) strain could grow on minimal media (prototroph), the mutant strains (auxotrophs) required additional nutrients.

4. **Conclusion**:
- Based on this understanding, the correct term for the mutant microorganism described in the question is **auxotroph**. An auxotroph is a mutant that cannot synthesize a specific compound and requires it to be provided externally for growth.

### Final Answer:
The mutant microorganism unable to synthesize a compound required for its growth but able to grow if the compound is provided is known as an **auxotroph**.

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