Mutations Flashcards
Mutation
Small permanent change in the DNA of an organism.
Point Mutation
A change in a single nucleotide in the DNA code that may result in translation of one different amino acid in a polypeptide sequence.
Somatic Mutation
A mutation in the somatic tissue of an organism that affects the specific cell type but is not inherited.
Germline Mutation
A heritable change in the DNA that occurs in a germ cell (a cell destined to become an egg or sperm) or the zygote at the single-cell stage and is also incorporated in every cell of the body.
Frameshift Mutation
The deletion or insertion of a single or non-multiple of three nucleotides into the DNA.
Chromosome Mutation
A change in the chromosome structure or number, often due to an error in pairing during the crossing over stage of meiosis.
Homologos
Two chromosomes that are homologous; during meiosis, the set of paring maternal and paternal chromosomes have the same genes at the same loci but may have different alleles.
Chromosome Deletion
Loss of a part of a chromosome during DNA replication.
Duplication
Any repetition of a region of DNA that contains one or more genes.
Translocation
Movement of a chromosomal segment from one position to another, either within the same chromosome or to another chromosome.
Inversion
A chromosome rearrangement in which a segment of chromosome is reversed end to end.
Nondisjunction
The failure of homologous chromosomes or sister chromatids to separate during meiosis.
Aneuploidy
Presence of an abnormal number of chromosomes in a cell.
Autosomal Aneuploidy
Presence of an abnormal number of autosomal chromosomes.
Sexual Aneuploidy
Presence of an abnormal number of sex chromosomes in a sex cell.