2.4 mutations and genetic diseases

• mutation: a heritable change in the sequence of nitrogen bases along a DNA molecule
• point mutation: the substitution of one nucleotide base for another during DNA replication
• frameshift mutation: the deletion or addition of a nucleotide during DNA replication. this change causes the three-letter grouping of frames in DNA to be read in an alternate pattern
• genetic disease: a disease caused by a mutation of one or more genes that can be inherited bu future generations
• carrier: an individual who possesses a form of a gene (allele), that results in a disease but does not demonstrate, exhibit or show the symptoms of that disease. however, this individuals can pass the disease-causing allele to his or her offspring
• mutagen: any agent that causes the likelihood of mutations to increase
• carcinogen: any agent that causes the likelihood of cancer to increase. many carcinogens are also mutagens
• pedigree: a set of standard symbols used as a tool for geneticists to trace a particular trait. it is like a genetic family tree
• transformation: the process by which free DNA is incorporated into a bacterial cell
• plasmid: a self-replicating circular piece of DNA that can be transferred between bacteria. plasmid transfer allows for the sharing of genes on the plasmids between bacteria