An amino acid which is precursor of lndole 3-acetic acid (Auxin) is

Options

A. glycine
B. valine
C. glutamic
D. tryptophan

Answer

To solve the question of which amino acid is a precursor of Indole-3-acetic acid (IAA), also known as auxin, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Auxins**: Auxins are a class of plant hormones that play a crucial role in growth and development. The most common natural auxin is Indole-3-acetic acid (IAA).

2. **Identifying the Precursor**: To determine which amino acid serves as a precursor for IAA, we need to know the biochemical pathway involved in the synthesis of auxins.

3. **Reviewing the Options**: The options given are:
- Glycine
- Valine
- Glutamic acid
- Tryptophan

4. **Analyzing Each Option**:
- **Glycine**: This is a simple amino acid but is not involved in the synthesis of IAA.
- **Valine**: Another amino acid that does not play a role in auxin production.
- **Glutamic Acid**: While important in various metabolic pathways, it is not a precursor of IAA.
- **Tryptophan**: This is a heterocyclic amino acid that is known to be a precursor for the synthesis of IAA.

5. **Conclusion**: Based on the analysis, Tryptophan is the amino acid that serves as a precursor for Indole-3-acetic acid (Auxin).

### Final Answer:
The amino acid which is a precursor of Indole-3-acetic acid (Auxin) is **Tryptophan**.

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