Which chromosomal mutation rearranges the order of genes on a chromosome without changing the amount of genetic material?

Which chromosomal mutation rearranges the order of genes on a chromosome without changing the amount of genetic material?

• A. Inversion chromosomal mutation
• B. Duplication chromosomal mutation
• C. Translocation chromosomal mutation
• D. Polyploidy

Answer: (A)

The main idea here is that some chromosomal mutations change the order of genes without changing how much DNA is present. An inversion does exactly that: a segment of the chromosome breaks, flips around, and reattaches in the reverse orientation. The same amount of genetic material remains; only the gene order is altered. This can affect how genes are expressed or how chromosomes pair during meiosis, even though no new material is added or lost. Other mutations involve changes in material amount or location. Duplication adds extra copies of a segment, increasing DNA content. Translocation moves segments to a different chromosome (or exchanges them between chromosomes), which can preserve material amount if balanced but changes chromosomal location and arrangement. Polyploidy doubles or triples the entire chromosome set, drastically increasing the genome size. So, the mutation that rearranges gene order on a chromosome without changing the total amount of genetic material is an inversion.

The main idea here is that some chromosomal mutations change the order of genes without changing how much DNA is present. An inversion does exactly that: a segment of the chromosome breaks, flips around, and reattaches in the reverse orientation. The same amount of genetic material remains; only the gene order is altered. This can affect how genes are expressed or how chromosomes pair during meiosis, even though no new material is added or lost.

Other mutations involve changes in material amount or location. Duplication adds extra copies of a segment, increasing DNA content. Translocation moves segments to a different chromosome (or exchanges them between chromosomes), which can preserve material amount if balanced but changes chromosomal location and arrangement. Polyploidy doubles or triples the entire chromosome set, drastically increasing the genome size.

So, the mutation that rearranges gene order on a chromosome without changing the total amount of genetic material is an inversion.