The phenomenon in which genes have two or more alleles that are common in a population is known as

Options

A. Polygenic inheritance
B. Polymorphism
C. Polyploidy
D. Polygamy

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about a phenomenon where genes have two or more alleles that are common in a population.

2. **Identifying Key Terms**: The key terms here are "genes," "alleles," and "population." Alleles are different forms of a gene, and when a gene has multiple alleles, it indicates genetic diversity within a population.

3. **Defining the Phenomenon**: The phenomenon where a gene has two or more alleles is known as **polymorphism**. This term specifically refers to the occurrence of multiple alleles for a single gene within a population.

4. **Types of Polymorphism**: Polymorphism can be categorized into two types:
- **Balanced Polymorphism**: This occurs in stable communities where different alleles are maintained at stable frequencies.
- **Transient Polymorphism**: This occurs in populations undergoing evolutionary changes or pressures, leading to fluctuations in allele frequencies.

5. **Examples of Polymorphism**: Common examples of polymorphism include variations in traits such as skin color and hair color among humans. For instance, within a population, individuals may have brown, black, or blonde hair, and varying skin tones from dark to fair.

6. **Conclusion**: Therefore, the answer to the question is that the phenomenon in which genes have two or more alleles that are common in a population is known as **polymorphism**.

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