Balancing selection ' promotes `:`

Options

A. Homozygotes
B. Heterozygotes
C. Polyplods
D. Recessive traits.

Answer

To solve the question "Balancing selection promotes:", we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Balancing Selection**:
- Balancing selection is a type of natural selection that maintains multiple alleles at a locus within a population. This means that instead of one allele becoming dominant, several alleles can coexist.

**Hint**: Think about how different alleles can contribute to the survival of a population.

2. **Gene Pool and Genetic Polymorphism**:
- In the context of a population, the gene pool refers to the total collection of genes and their alleles. Balancing selection helps maintain genetic diversity, known as genetic polymorphism, within this gene pool.

**Hint**: Consider what genetic diversity means for a population's adaptability.

3. **Heterozygote Advantage**:
- One of the key outcomes of balancing selection is the promotion of heterozygotes. Heterozygotes are individuals that have two different alleles for a particular gene. This genetic variation often leads to a survival advantage in changing environments.

**Hint**: Reflect on how having different alleles might help an organism survive better than those with two identical alleles.

4. **Conclusion**:
- Based on the understanding of balancing selection and its role in promoting genetic diversity, we conclude that balancing selection promotes heterozygotes.

**Final Answer**: Balancing selection promotes **heterozygotes** (Option B).