Two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes are reversed in one cross, is known as:

Options

A. Test cross
B. Reciprocal cross
C. Dihybrid cross
D. Reverse cross

Answer

To solve the question regarding the definition of two crosses between the same pair of genotypes or phenotypes where the sources of the gametes are reversed in one cross, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terminology**:
- First, we need to clarify the terms involved in the question: test cross, reciprocal cross, dihybrid cross, and reverse cross.

2. **Identifying the Cross Types**:
- **Test Cross**: This involves crossing an individual with a recessive individual to determine the genotype of the former.
- **Reciprocal Cross**: This is a cross between the same genotypes or phenotypes, but the sources of the gametes are reversed. For example, if we cross a male with a trait A with a female with a trait B, the reciprocal cross would be crossing a female with trait A with a male with trait B.
- **Dihybrid Cross**: This involves two traits being studied simultaneously (e.g., tall vs. dwarf and round vs. wrinkled seeds).
- **Reverse Cross**: This term typically refers to crossing the offspring of an F1 generation with one of the original parents.

3. **Analyzing the Options**:
- Given the definitions, we can analyze which option fits the description of reversing the sources of gametes in the same pair of genotypes or phenotypes.

4. **Conclusion**:
- The correct answer is **reciprocal cross**. This is because it specifically involves reversing the sources of gametes while maintaining the same pair of genotypes or phenotypes.

### Final Answer:
The term for two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes are reversed in one cross is **reciprocal cross**.

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