A chestnut-colored horse is mated with a cremello-colored horse. Over a 10-year period, all of their offsprings are palominos. This pattern of inheritance is best explained by

Options

A. complete dominance.
B. incomplete dominance.
C. multiple gene effects.
D. environmental effects on genes.

Answer

To solve the question regarding the inheritance pattern observed in the offspring of a chestnut-colored horse and a cremello-colored horse, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Colors and Their Genetic Basis**:
- Chestnut color in horses is typically a result of the presence of a specific allele (let's denote it as "C").
- Cremello color is a result of a different genetic makeup, often represented as "cc" (homozygous for the cream allele).

2. **Understand the Offspring Color**:
- The offspring produced from the mating of a chestnut horse (C) and a cremello horse (cc) are all palominos. Palomino horses are characterized by a golden color, which is a result of the chestnut allele interacting with the cream allele.

3. **Determine the Genotypes of the Parents**:
- The chestnut horse could be either homozygous (CC) or heterozygous (Cc).
- The cremello horse is homozygous for the cream allele (cc).

4. **Perform a Punnett Square Analysis**:
- If the chestnut horse is heterozygous (Cc), the potential offspring genotypes would be:
- Cc (palomino)
- cc (cremello)
- If the chestnut horse is homozygous (CC), all offspring would be Cc (palomino).

5. **Conclusion**:
- Since all offspring are palominos, it is likely that the chestnut horse is heterozygous (Cc). This explains why all offspring are palominos (Cc) when mated with the cremello horse (cc).

### Final Answer:
This pattern of inheritance is best explained by the fact that the chestnut horse is heterozygous (Cc) and the cremello horse is homozygous (cc), resulting in all offspring being palominos (Cc).

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