When a grey color seed producing pea plant is crossed to white color seed producing pea plant, in the progeny 164 grey seed producing and 156 white seed producing plants are obtained. This cross is

Options

A. Receprocal cross
B. Test cross
C. Incomplete dominance
D. Codominance

Answer

To determine the type of cross when a grey seed producing pea plant is crossed with a white seed producing pea plant, and the progeny consists of 164 grey seed producing plants and 156 white seed producing plants, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Phenotypes**:
- The grey seed color is one phenotype, and the white seed color is another phenotype.

2. **Count the Progeny**:
- In the progeny, we have 164 grey seed producing plants and 156 white seed producing plants.

3. **Calculate the Ratio**:
- To find the ratio of grey to white seeds, we can express it as:
\[ \text{Ratio} = \frac{164}{156} \approx 1.05 \text{ (which is close to 1:1)} \]

4. **Determine the Type of Cross**:
- A 1:1 ratio in the progeny typically indicates a test cross, which occurs when a homozygous recessive individual is crossed with a heterozygous individual. In this case, since the grey seeds and white seeds are both present in nearly equal proportions, it suggests that the grey seed plant is heterozygous.

5. **Eliminate Other Options**:
- **Reciprocal Cross**: This involves switching the sexes of the parents but does not affect the ratio outcome.
- **Incomplete Dominance**: This would result in a blending of traits, which is not observed here.
- **Co-Dominance**: This would show both traits distinctly in the offspring, which is also not the case.

6. **Conclusion**:
- Since the progeny shows a 1:1 ratio of grey to white seeds, the type of cross is identified as a **test cross**.

### Final Answer:
The cross is a **test cross**.