In corn, the trait for a tall plant (T) is dominant to the trait for a dwarf plant (t) and the trait for coloured kernels (C ) is dominant to the trait for white kernels (c ). In a particular cross of corns, probability of white kernels is 0.25 and the probability of a kernel being coloured is 0.75 which of the following most probably represnts the parental genotypes?

Options

A. `TtCc xx TtCc`
B. `TtCc xx t tCc`
C. `TtCc xx t t c c`
D. `T TCc xx t tCc`

Answer

To solve the problem, we need to determine the parental genotypes for a cross involving two traits in corn: plant height (tall vs. dwarf) and kernel color (colored vs. white).

### Step-by-Step Solution:

1. **Identify the Traits and Their Alleles:**
- Tall plant (T) is dominant to dwarf plant (t).
- Colored kernels (C) are dominant to white kernels (c).

2. **Understand the Probabilities Given:**
- The probability of white kernels is 0.25 (25%).
- The probability of colored kernels is 0.75 (75%).

3. **Analyze the Kernel Color Probability:**
- The probability of getting white kernels (cc) indicates that the only way to have white kernels is if both alleles are recessive (cc).
- The 0.25 probability of white kernels suggests that the cross must produce a 1:3 ratio of white to colored kernels.

4. **Determine Possible Parental Genotypes for Kernel Color:**
- A 1:3 ratio of white to colored kernels can arise from a cross between two heterozygous parents (Cc x Cc).
- This cross results in:
- 1 CC (colored)
- 2 Cc (colored)
- 1 cc (white)
- Therefore, the probability of white kernels (cc) is 1 out of 4 (0.25), and colored kernels (CC or Cc) is 3 out of 4 (0.75).

5. **Consider the Height Trait:**
- The height trait (T/t) does not affect the kernel color ratio due to the law of independent assortment.
- The parental genotypes for height can be any combination (TT, Tt, or tt) since they do not influence the kernel color outcome.

6. **Conclusion on Parental Genotypes:**
- The most probable parental genotypes for the kernel color trait are both heterozygous (Cc x Cc).
- The height trait can be any combination, but it is not necessary to determine the kernel color outcome.

### Final Answer:
The most probable parental genotypes are:
- For kernel color: Cc (heterozygous) x Cc (heterozygous)
- For height: Any combination (TT, Tt, or tt)

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