Question

A genetic linkage map represents the

• A. relative locations of genes on a chromosome
• B. distribution of the mutational hotspots
• C. phylogenetic linkage among organisms
• D. accurate physical distances among loci

Answer 1

The Correct Option is A

To understand what a genetic linkage map represents, we need to clarify each of the provided options:

1. Relative locations of genes on a chromosome: A genetic linkage map, also known as a genetic map, is indeed used to depict the relative positions of genes along a chromosome. The map is constructed based on the frequency of recombination between markers, which indicates how far apart on the chromosome they are. The closer they are, the less likely recombination will occur between them, indicating closer linkage.
2. Distribution of the mutational hotspots: This option refers to areas in a genome that are more prone to mutations. Mutational hotspots are not the primary focus of a genetic linkage map.
3. Phylogenetic linkage among organisms: Phylogenetic linkage involves the evolutionary relationship between different species. This is generally represented by a phylogenetic tree, not a genetic linkage map.
4. Accurate physical distances among loci: While a genetic linkage map provides a relative placement of genes or markers, it does not provide precise physical distances. Physical maps, which use techniques like sequencing, offer accurate measurements, unlike linkage maps based on recombination frequencies.

The correct explanation and option is:

1. Relative locations of genes on a chromosome.

This option correctly describes what a genetic linkage map represents. It provides a visual illustration of genetic loci based on their genetic distance, rather than physical distance, leading to an understanding of gene linkage and inheritance patterns.