14. A mechanism that can cause a gene to move from one linkage group to another is
(1) crossing over            (2) inversion
(3) translocation             (4) duplication

Concept: linkage groups and movement of genes

A linkage group is essentially a chromosome: all genes on the same chromosome tend to be inherited together.
To move a gene from one linkage group to another, a piece of one chromosome must be broken off and attached to a non‑homologous chromosome. That process is called chromosomal translocation.

Option‑wise explanation

1. Crossing over

   • Exchange of segments between homologous chromosomes (same linkage group) during meiosis.

   • Shuffles alleles within a linkage group but does not move genes to a different chromosome.

2. Inversion

   • A segment is cut out and reinserted in reverse orientation on the same chromosome.

   • Changes gene order but keeps all genes in the same linkage group.

3. Translocation – correct

   • A segment of one chromosome breaks and attaches to a non‑homologous chromosome.

   • This moves genes physically from one chromosome (linkage group) to another, creating new linkage relationships.

4. Duplication

   • A chromosomal segment is copied and inserted again in the same chromosome (or sometimes nearby on the same arm).

   • In typical textbook context, it alters copy number and order but not the linkage group of the original gene set.

So, the structural change that can cause a gene to move from one linkage group (chromosome) to another is translocation (option 3).