Which mutation produces extra copies of parts of a chromosome?

Which mutation produces extra copies of parts of a chromosome?

• A. Deletion
• B. Duplication
• C. Inversion
• D. Translocation

Answer: (B)

Duplications create extra copies of parts of a chromosome. This mutation occurs when a chromosome segment is replicated or misaligned so that an additional copy is inserted into the same chromosome. The result is more copies of the genes in that region, which can alter gene dosage and affect phenotype. Other chromosomal changes don’t add copies. A deletion removes material, reducing copy number. An inversion flips a segment within the chromosome but keeps the same amount of DNA. A translocation moves a segment to another chromosome, changing location rather than increasing the number of copies of that segment.

Duplications create extra copies of parts of a chromosome. This mutation occurs when a chromosome segment is replicated or misaligned so that an additional copy is inserted into the same chromosome. The result is more copies of the genes in that region, which can alter gene dosage and affect phenotype.

Other chromosomal changes don’t add copies. A deletion removes material, reducing copy number. An inversion flips a segment within the chromosome but keeps the same amount of DNA. A translocation moves a segment to another chromosome, changing location rather than increasing the number of copies of that segment.