What is a genetic marker?

A genetic marker is defined as a DNA sequence that can identify a particular trait or gene. This means that genetic markers serve as indicators or reference points in the genome that can be used to track inheritance patterns or identify specific genetic traits. They can be used in a variety of applications, such as genetic mapping, identifying individuals in forensic studies, and researching heredity traits within populations.

Genetic markers can be associated with various traits, including those linked to diseases, allowing scientists and researchers to locate specific genes on chromosomes more effectively. This role is foundational in fields like biotechnology, genetics, and personalized medicine, as it enables more precise manipulation and study of genetic sequences.

The other options provided are not accurate representations of what a genetic marker is. Genetic therapy refers to treatments designed to modify genes to combat or prevent disease, which is a different concept altogether. A visible change in phenotype relates to observable traits resulting from the expression of genes, and while these changes may be associated with genetic markers, they do not define what a genetic marker is. An enzyme used in DNA replication, such as DNA polymerase, plays a crucial role in copying DNA but does not pertain to the identification of traits or genes.