Question

The expression of some genes is dependent upon their chromosomal position. Which kind of chromosome rearrangement would most likely cause a position-effect phenotype?

1) Deletion
2) Tandem Duplication
3) Inversion
4) All of the above

Answer 1

An inversion, which rotates a segment of a chromosome and reinserts it, is most likely to cause a position-effect phenotype by changing the local environment and orientation of the genes 4)

Step-by-step explanation:

The expression of some genes is dependent upon their chromosomal position, therefore, a chromosomal rearrangement that would most likely cause a position-effect phenotype is inversion.

An inversion involves detaching a segment of the chromosome, rotating it 180°, and then reinserting it.

This alteration can result in genes being positioned next to regulatory sequences they were not originally near, potentially causing abnormal expression patterns.

4) Both deletions and tandem duplications can also affect gene expression,

but inversions are particularly likely to do so because they change the orientation and possibly the local environment of the genes without removing or duplicating genetic material.