1.mutagenic
Definition:
Refers to something that causes mutations; mutagenic substances may also be carcinogenic (cause cancer).
1.amber mutation
Definition:
A mutation from a codon which codes for an amino acid into the amber codon UAG, which normally signals that the translation of mRNA into an amino acid chain should stop. The mutation causes the amino acid chain to stop forming before it is actually completed.
2.back mutation
Definition:
A mutation that causes a mutant gene to revert to its original wild-type base sequence. This is the opposite of a forward mutation.
3.chromosomal mutation
Definition:
Can refer to any of a number of DNA mutations which results in a change in the protein encoded by the mutated gene, such as point mutations, insertion or deletion mutations (frameshift mutations), or nonsense mutations. More often this refers to mutations involving chromosomes, such as the inversion of part of one chromosome such that
the inverted part no longer matches with its homologous pair, a translocation of one part of a chromosome to a different chromosome, deletions of parts of chromosomes, or accidents which happen during the division of the nucleus like the unequal portioning of chromosomes between the daughter cells.
4.conditional mutation
Definition:
A mutation which makes itself apparent only under certain conditions, such as low or high temperatures.
5.deletion mutation
Definition:
A mutation cause by the removal of one or more nucleotides from a gene or chromosome.
6.down promoter mutation
Definition:
A mutation (a change in base pair sequence) in a promoter region; this results in lower gene expression (less
transcription of the gene occurs).
7.forward mutation
Definition:
Any mutation which renders a formerly functional gene nonfunctional. This is the opposite of a back mutation.
8.frameshift mutation (frame shift mutation, frame-shift mutation)
Definition:
A type of mutation in which one or more paired nucleotides are inserted or deleted in the coding region of a gene, which causes the triplet codons to be read in the wrong frame; the resulting polypeptide has a garbled amino acid sequence from the mutated codon on.
9.germinal mutation
Definition:
A mutation in the germ cells (the cells which will undergo meiosis to form the gametes). Such mutations are therefore passed on to offspring.
10.homeotic mutation
Definition:
A mutation that causes an organism to develop a homologous body part or structure in place of the part or structure that should normally be there (e.g., developing a hand in place of a foot).
11.induced mutation
Definition:
A mutation, or change in a nucleotide sequence or gene, which was caused by a mutagen.
12.insertion mutation
Definition:
A mutation caused by the insertion of at least one extra nucleotide base in a DNA sequence.
13.lethal mutation
Definition:
A mutation that disrupts a critical gene, thus killing the developing organism.
14.mutation (adj. mutant)
Definition:
A heritable change in DNA sequence resulting from mutagens. Various types of mutations include frame-shift mutations, missense mutations, and nonsense mutations.
15.nonsense mutation
Definition:
A mutation that causes a polypeptide chain to be ended prematurely.
16.point mutation
Author: Susan A.Hagedorn
Definition:
A change in a single base pair of a DNA sequence in a gene.
17.polar mutation (polarity mutation)
Definition:
A mutation in a single gene which affects the rate of expression of other genes that are near it on a chromosome.
18.silent mutation
Definition:
A mutation that causes no moticeable change in the biological activity of the proteins the gene codes for.
19.spontaneous mutation
Definition:
A mutation which occurs by itself without first being affected by a mutagen, for example during the process of
DNA replication. Spontaneous mutations arise at a remarkably constant rate. The rate that spontaneous mutations arise has been used as an evolutionary clock to estimate how closely related two (or more) separate species are to each other.
20.substitution mutation
Definition:
A mutation caused by a nucleotide base being replaced by a different one.
21.suppressor mutation
Definition:
A mutation that restores, at least to some degree, a function lost as the result of a primary mutation; the
suppressor mutation is at a different site from the primary mutation.
22.unstable mutation
Definition:
A mutation that has a high likelihood of reverting to its original form.
23.up mutation
Definition:
Refers to any mutation in the promoter region of a gene which can trigger transcription initiation. |
