Alleles that produce independent effects in their heterozygous condition are called

Options

A. codominant alleles
B. epistatic alleles
C. complementary alleles
D. supplementary alleles

Explanation

To solve the question regarding alleles that produce independent effects in their heterozygous condition, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks about the type of alleles that exhibit independent effects when present in a heterozygous condition.

2. **Define Key Terms**:
- **Heterozygous Condition**: This refers to having two different alleles for a particular gene (e.g., Aa).
- **Independent Effects**: This means that both alleles can express their traits without one overshadowing the other.

3. **Evaluate the Options**:
- **Co-dominant Alleles**: These alleles express both traits equally in a heterozygous condition. For example, in the case of blood types, both A and B alleles are expressed in AB blood type.
- **Epistatic Alleles**: These alleles can mask the expression of other alleles, thus not producing independent effects.
- **Complementary Alleles**: These are alleles that work together to produce a phenotype, but do not express independently.
- **Supplementary Alleles**: These alleles also do not express independently and often require the presence of another allele to show their effects.

4. **Identify the Correct Answer**: Based on the definitions and effects of the alleles, co-dominant alleles are the only type that produces independent effects in a heterozygous condition.

5. **Conclusion**: Therefore, the correct answer to the question is **co-dominant alleles**.

### Final Answer:
Co-dominant alleles.

---