Fruit colour in squash is an example of

Options

A. Recessive epistasis
B. Dominant epistasis
C. Complementary genes
D. Inhibitory genes

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the genetic basis of fruit color in squash. We need to identify the type of genetic interaction that leads to the expression of different fruit colors.

2. **Identifying the Phenotypes**: In squash, there are three observed fruit colors: white, yellow, and green. We need to establish which of these colors is dominant and which are recessive.

3. **Determining Dominance**: It is noted that white is the dominant phenotype, while yellow and green are recessive. This means that the presence of the white allele will mask the expression of the yellow and green alleles.

4. **Identifying the Genes Involved**: The color of the squash fruit is determined by two genes, which we can denote as W (for white) and Y (for yellow). The presence of the dominant W allele will result in a white fruit regardless of the Y allele's state.

5. **Genotype and Phenotype Relationships**:
- **White Fruit**: Genotype can be either WW or WY (where Y can be present in any form).
- **Yellow Fruit**: Genotype must be wwY (where W is recessive).
- **Green Fruit**: Genotype must be wwyy (where both alleles are recessive).

6. **Conclusion on Genetic Interaction**: Since the presence of the dominant W allele overrides the expression of the Y allele, this interaction is classified as dominant epistasis. In this case, the dominant allele of one gene (W) masks the expression of alleles at another gene (Y).

7. **Final Answer**: Therefore, the correct answer to the question is that fruit color in squash is an example of **dominant epistasis**.

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