Question

Which of the fol lowing chromosomal changes is usually the most damaging when in the homozygous condition?

Options

• Deletion

• Duplication

• Translocation

• Inversion

Answer 1

Deletion

Explanation:

Deletion is usually the most damaging chromosomal change when in the homozygous condition because it results in the loss of a section of a chromosome, which may involve one or more genes. This loss disrupts the genic balance and affects the phenotype severely. Other changes like duplication, translocation, and inversion do not involve loss of genetic material but rather rearrangements or additions, which tend to be less deleterious, especially in the homozygous state. Therefore, deletions tend to cause the most serious effects when both homologous chromosomes carry the deletion.