The equivalent of a structural gene is

Options

A. muton
B. cistron
C. operon
D. recon

Answer

To answer the question "The equivalent of a structural gene is?", we will analyze the options provided and identify the correct one step by step.

### Step 1: Understand the definition of a structural gene
A structural gene is a segment of DNA that codes for a specific protein or polypeptide. It is responsible for the synthesis of proteins that play various roles in the cell.

**Hint:** Remember that structural genes are directly involved in coding for proteins.

### Step 2: Analyze the options
1. **Muton**: This refers to the smallest unit of DNA that can undergo mutation. It is not equivalent to a structural gene as it does not specifically refer to a gene that codes for a protein.

**Hint:** Think about whether this term relates to protein coding.

2. **Cistron**: This term is often used interchangeably with a structural gene. A cistron is a segment of DNA that can code for a single polypeptide chain.

**Hint:** Focus on terms that directly relate to the coding of proteins.

3. **Operon**: An operon is a cluster of genes that are transcribed together under the control of a single promoter. While it involves structural genes, it is not equivalent to a single structural gene.

**Hint:** Consider whether this term refers to a single gene or a group of genes.

4. **Recon**: A recon is a segment of DNA that is capable of undergoing recombination or crossing over. This term does not relate to the coding function of a structural gene.

**Hint:** Think about the function of this term in relation to genetic recombination.

### Step 3: Identify the correct answer
After analyzing all the options, the correct answer is **Cistron**. A cistron is indeed the equivalent of a structural gene as it refers to a segment of DNA that codes for a specific polypeptide.

**Final Answer:** The equivalent of a structural gene is **Cistron**.