Translocation occurs during spontaneous chromosomal aberrations. During transclocation there is

Options

A. an addition of a segment of a chromosome to same chromosome
B. loss of a segment of chromsome
C. transfer of a segment of a chromosome to a different chromosome
D. all of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Translocation**: Translocation is a type of chromosomal aberration that involves the rearrangement of parts between non-homologous chromosomes. This means that segments of one chromosome break off and attach to another chromosome that is not its homolog.

2. **Chromosomal Structure**: Consider two chromosomes, for example, chromosome 1 (with segments P, Q, R, S) and chromosome 2 (with segments D, U, V, W). During translocation, a segment from one chromosome (let's say from chromosome 1) can break off and attach to a non-homologous chromosome (chromosome 2).

3. **Mechanism of Translocation**: In the process of translocation, a part of the chromosome is lost (the segment that breaks off) and this segment is then transferred to a different, non-homologous chromosome. This can lead to changes in gene expression and can result in various genetic disorders.

4. **Example of Translocation**: A well-known example of translocation is Philadelphia syndrome, where a segment from the long arm of the 22nd chromosome breaks off and attaches to the 9th chromosome. This specific translocation is often associated with certain types of leukemia.

5. **Conclusion**: The correct answer to the question about what occurs during translocation is that there is a transfer of a segment of one chromosome to a different, non-homologous chromosome.

**Final Answer**: During translocation, there is a transfer of a segment of the chromosome to a different chromosome.

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