Which is the most common mechanism of genetic varisation in the poplulation of a sexually-reproducing organism

Options

A. Chromosomal aberrations
B. Genetic drift
C. Recombination
D. Transduction

Answer

**Step-by-Step Solution:**

1. **Understanding Genetic Variation**: Genetic variation refers to the diversity in gene frequencies among individuals within a population. In sexually reproducing organisms, this variation is crucial for evolution and adaptation.

2. **Identifying Mechanisms of Genetic Variation**: The question presents four mechanisms:
- Chromosomal aberration
- Genetic drift
- Recombination
- Transduction

3. **Analyzing Each Mechanism**:
- **Chromosomal Aberration**: This involves structural changes in chromosomes, which can lead to genetic disorders but is not the most common mechanism for genetic variation in sexually reproducing organisms.
- **Genetic Drift**: This is a random process that can lead to changes in allele frequencies in a population, but it does not directly contribute to genetic variation in the context of sexual reproduction.
- **Recombination**: This is the process where genetic material is exchanged between homologous chromosomes during meiosis, specifically during the pachytene stage of prophase I. This exchange creates new combinations of genes, leading to genetic variation in the offspring.
- **Transduction**: This is a process related to bacterial reproduction and involves the transfer of DNA from one bacterium to another via a virus, which is not applicable to most sexually reproducing organisms.

4. **Conclusion**: Among the mechanisms listed, recombination is the most common mechanism of genetic variation in sexually reproducing organisms due to its role in generating new allele combinations during meiosis.

5. **Final Answer**: The most common mechanism of genetic variation in the population of a sexually-reproducing organism is **recombination**.

---