In………. Both dominant and recessive alleles lack their dominant and recessive relationships

Options

A. Incomplete dominance
B. Polygenic inheritance
C. Multiple alleles
D. Codominance

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a condition in which both dominant and recessive alleles lack their typical relationships, meaning they do not exhibit the usual dominance or recessiveness.

2. **Analyzing the Options**:
- **Option 1: Incomplete Dominance**: In this scenario, neither allele is completely dominant over the other. Instead, they blend together to create a third phenotype. This does not fit the requirement since both alleles are partially expressed, not lacking their relationships.

- **Option 2: Polygenic Inheritance**: This refers to a situation where multiple genes contribute to a single trait. This option does not pertain to the relationship between dominant and recessive alleles, so it is not the correct answer.

- **Option 3: Multiple Allelism**: This involves a single gene having more than two alleles. While it can show various phenotypes, it does not specifically address the relationship between dominant and recessive alleles. Therefore, this option is also incorrect.

- **Option 4: Co-dominance**: In co-dominance, both alleles are fully expressed in the phenotype of the organism. This means that neither allele is dominant or recessive, and both contribute equally to the phenotype. This matches the requirement of the question.

3. **Conclusion**: Based on the analysis, the correct answer is **Option 4: Co-dominance**.