mutation of a cell

Codon

A sequence of three mRNA bases that codes for one amino acid or a stop signal.

Triplet Code

The genetic code called because codons are sequences of three bases.

Degeneracy

The phenomenon where most amino acids are encoded by more than one codon.

Start Codon

AUG, which codes for methionine and initiates translation.

Stop Codons

UAA, UAG, UGA, which terminate translation.

Mutation

A permanent change in DNA sequence that can alter protein structure and function.

Neutral Mutation

Mutations that occur in noncoding DNA or change a codon but not the amino acid.

Functional Mutation

Mutations that alter the amino acid sequence and can be harmful, lethal, or beneficial.

Point Mutation

A mutation that affects a single nucleotide.

Substitution Mutation

A mutation where one base replaces another, which can be silent, missense, or nonsense.

Frameshift Mutation

Mutations caused by insertion or deletion that shift the reading frame and alter all downstream codons.

Chromosomal Mutation

Large-scale changes in chromosome structure or number, often occurring during meiosis.

Genetic Load

The accumulation of mutations within a population.

Beneficial Mutation

A mutation that increases survival and reproduction.

Physical Mutagens

Agents like UV light and ionizing radiation that cause mutations.

Chemical Mutagens

Substances such as cigarette smoke and pesticides that can cause mutations.

Biological Mutagens

Viruses that cause mutations, including oncogenic viruses associated with cancer.