The longer the chromosome of an organism, the more genetic variability it gets from :-

Options

A. Independent assortment
B. Linkage
C. Crossing over
D. Mutation

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks about the relationship between the length of chromosomes in an organism and the source of genetic variability.

2. **Identifying the Options**: The options provided are:
- Independent assortment
- Linkage
- Crossing over
- Mutation

3. **Analyzing Each Option**:
- **Independent Assortment**: This refers to the random distribution of maternal and paternal chromosomes into gametes during meiosis. While it contributes to genetic variability, it is not directly related to chromosome length.
- **Linkage**: This describes genes that are located close together on the same chromosome and tend to be inherited together. Linkage reduces genetic variability because linked genes do not assort independently.
- **Crossing Over**: This is the process where homologous chromosomes exchange segments of genetic material during prophase I of meiosis. This exchange increases genetic variability by creating new combinations of alleles.
- **Mutation**: This refers to changes in the DNA sequence. While mutations can introduce variability, they are not directly influenced by chromosome length.

4. **Conclusion**: The process that directly relates to the length of chromosomes and increases genetic variability is **crossing over**. Longer chromosomes have more genes, which can lead to more opportunities for crossing over and thus greater genetic variability.

5. **Final Answer**: The correct option is **crossing over**.

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