Cis tans expression of genes is an example of

Options

A. Mutation
B. Intergenic crossing over
C. Intragenic crossing over
D. Cytoplasimic inheritance

Answer

To solve the question regarding the "cis-trans expression of genes," we will analyze the options provided and determine which one correctly describes this phenomenon.

### Step-by-Step Solution:

1. **Understanding Cis-Trans Expression**:
- The term "cis-trans expression" refers to the arrangement of alleles on homologous chromosomes. In a cis configuration, two alleles are on the same chromosome, while in a trans configuration, they are on opposite chromosomes.

2. **Analyzing the Options**:
- **Option A: Mutation**: This refers to a change in the DNA sequence of a gene. Since cis-trans expression does not involve a change in the DNA sequence, this option is incorrect.
- **Option B: Intergenic Crossing Over**: This refers to the exchange of genetic material between two different genes located on the same chromosome. This is a potential candidate since it involves the interaction of two genes.
- **Option C: Intragenic Crossing Over**: This refers to crossing over that occurs within a single gene. Since cis-trans expression involves two different genes, this option is not applicable.
- **Option D: Cytoplasmic Inheritance**: This involves the transmission of genetic material located in the cytoplasm (e.g., mitochondrial DNA). It does not pertain to the arrangement of alleles on chromosomes, so this option is incorrect.

3. **Identifying the Correct Answer**:
- Based on the analysis, the correct answer is **Option B: Intergenic Crossing Over**. This is because cis-trans expression involves the interaction between two different genes, which aligns with the definition of intergenic crossing over.

### Final Answer:
The correct answer is **intergenic crossing over**.

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