A linkage group is defined as

Answer

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

1. **Understanding Linkage Groups**: A linkage group refers to a set of genes that are located on the same chromosome. These genes are inherited together because they are physically close to each other on the chromosome.

2. **Gene Positioning**: For example, if we have genes A, B, C, and D located on a single chromosome, the distance between these genes can vary. The closer the genes are to each other, the less likely they are to be separated during the process of recombination.

3. **Recombination Frequency**: Genes that are closely located (like A and B) will show a lower frequency of recombination compared to genes that are farther apart (like A and D). This means that during meiosis, the chances of these genes being inherited together are higher.

4. **Definition of Linkage**: The term "linkage" refers to the phenomenon where genes that are located close to each other on the same chromosome tend to be inherited together. This is because the physical distance between them makes it less likely for them to be separated during crossing over.

5. **Conclusion**: Therefore, a linkage group is defined as all the genes that are located on the same chromosome. This means that they are linked together and will be passed on to the next generation as a unit.

**Final Answer**: A linkage group is defined as all the genes located on the same chromosome.

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