What is a genetic marker?

• A. A type of disease-causing agent
• B. A specific DNA sequence used to identify a particular gene or trait
• C. A scientist who studies genes
• D. A physical characteristic of an organism

Answer: (B)

A genetic marker is indeed defined as a specific DNA sequence that can be used to identify a particular gene or trait within an organism's genome. Genetic markers can come in various forms, such as single nucleotide polymorphisms (SNPs), insertions, deletions, or even larger regions of DNA. These markers are invaluable in genetic research and breeding programs because they help scientists track the inheritance of traits and establish associations between genetic sequences and phenotypic characteristics.

For example, in agricultural biotechnology, genetic markers facilitate the identification of plants that carry desirable traits, such as disease resistance or drought tolerance, allowing for more efficient breeding strategies. In human genetics, markers can link to various diseases, aiding in understanding genetic predispositions and aiding in personalized medicine. Thus, the role of genetic markers is crucial in genetics, genomics, and biotechnology, enabling the identification and study of specific traits or genes with precision.