The term test cross refers to a cross between:

Options

A. The crossing of `F_(1)` individual with homozygous recessive
B. Crossing of `F_(1)` individual with either of the two parents
C. Crossing of `F_(1)` individual with another `F_(1)` individual
D. Crossing `F_(1)` individual with that of `F_(2)`

Answer

To solve the question regarding the term "test cross," we need to understand the concept and the options provided. Here’s a step-by-step breakdown:

### Step-by-Step Solution:

1. **Understanding Test Cross**:
- A test cross is a genetic cross used to determine the genotype of an individual that exhibits a dominant phenotype but has an unknown genotype.

2. **Identifying the Cross**:
- The test cross specifically involves crossing the individual with a homozygous recessive individual. This allows us to observe the phenotypes of the offspring to infer the genotype of the unknown parent.

3. **Analyzing the Options**:
- **Option A**: Crossing of F1 individual with homozygous recessive - This is the correct definition of a test cross.
- **Option B**: Crossing of F1 individual with either of two parents - This describes a back cross, not a test cross.
- **Option C**: Crossing of F1 individual with another F1 individual - This is called selfing, which is not a test cross.
- **Option D**: Crossing F1 individual with that of F2 - This is not a standard definition of a test cross.

4. **Conclusion**:
- The correct answer is **Option A: Crossing of F1 individual with homozygous recessive**.