As a result of genetic alterations (mutations, insertions, deletions), the base composition at a particular location of the genome may be different in different plants. Full article >>> Biology Glossary search by EverythingBio.com A gene whose expression allows one to identify cells that have been transforrned or transfected with a vector containing the marker gene. home >> biology >> dictionary A marker pen, marking pen, felt-tip pen, or marker , is a pen which has its own ink-source, and usually a tip made of a porous material, such as felt or nylon. biological marker n 1. flanking marker An identifiable region (i.e., polymorphism ) located near a gene which can be used in linkage studies to track the coinheritance of the gene in question. A marker gene must be on the same chromosome as the target gene and near enough to it so that the two genes (the marker gene and the target gene) are genetically linked and are usually inherited together. NCI's Dictionary of Cancer Terms provides easy-to-understand definitions for words and phrases related to cancer and medicine. ADVERTISEMENTS: Molecular Markers: A molecular marker is a DNA sequence in the genome which can be located and identified. A genetic marker is a landmark. Genetic marker, any alteration in a sequence of nucleic acids or other genetic trait that can be readily detected and used to identify individuals, populations, or species or to identify genes involved in inherited disease. marker Medspeak A value or indicator of the presence of a disease. This usually deals with running an experiment (assay) to determine the presence, absence, and with some markers, abundance of a specific protein. Molecular biology An identifiable physical location on a chromosome (e.g., restriction enzyme cutting site, gene, minisatellite, microsatellite), the inheritance of which can be monitored. Narration. Genetic marker s: Alleles of genes, or DNA polymorphisms , used as experimental probe s to keep track of an individual, a tissue , a cell , a nucleus , a chromosome, or a gene. For example, you can use a protein marker to mark an extracellular protein such as a Lipopolysaccharide (LPS) on bacteria. These differences, collectively called as polymorphisms can be mapped and identified. The genetic marker itself may be a part of a gene or may have no known function. marker meaning: 1. a sign that shows where something is: 2. a characteristic feature, gene, or substance that…. Learn more. (Medicine) a substance, physiological characteristic, gene, etc that indicates, or may indicate, the presence of disease, a physiological abnormality or a psychological condition. A marker gene can serve as a flag for another gene, sometimes called the target gene. Marker gene: A detectable genetic trait or segment of DNA that can be identified and tracked. Also called: biomarker 2. […] A protein marker is just that - a marker for specific proteins. This is unlike an intragenic marker which is located within the gene itself. Genetic marker Any segment of DNA that can be identified, or whose chromosomal location is known, so that it can be used as a reference point to map or locate other genes. Genetic markers are used to track the inheritance of a nearby gene that has not yet been identified, but whose approximate location is known.