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mutation    音标拼音: [mjut'eʃən]
n. 变化,转变,元音变化

变化,转变,母音变化

mutation
n 1: (biology) an organism that has characteristics resulting
from chromosomal alteration [synonym: {mutant}, {mutation},
{variation}, {sport}]
2: (genetics) any event that changes genetic structure; any
alteration in the inherited nucleic acid sequence of the
genotype of an organism [synonym: {mutation}, {genetic mutation},
{chromosomal mutation}]
3: a change or alteration in form or qualities

mutation \mu*ta"tion\ (m[-u]*t[=a]"sh[u^]n), n. [L. mutatio, fr.
mutare to change: cf. F. mutation. See {Mutable}.]
Change; alteration, either in form or qualities.
[1913 Webster]

The vicissitude or mutations in the superior globe are
no fit matter for this present argument. --Bacon.
[1913 Webster]

2. (Biol.) Gradual definitely tending variation, such as may
be observed in a group of organisms in the fossils of
successive geological levels.
[Webster 1913 Suppl.]

3. (Biol.)
(a) As now employed (first by de Vries), a cellular
process resulting in a sudden inheritable variation
(the offspring differing from its parents in some
well-marked character or characters) as distinguished
from a gradual variation in which the new characters
become fully developed only in the course of many
generations. The occurrence of mutations, the
selection of strains carrying mutations permitting
enhanced survival under prevailing conditions, and the
mechanism of hereditary of the characters so
appearing, are well-established facts; whether and to
what extent the mutation process has played the most
important part in the evolution of the existing
species and other groups of organisms is an unresolved
question.
(b) The result of the above process; a suddenly produced
variation.

Note: Mutations can occur by a change in the fundamental
coding sequence of the hereditary material, which in
most organisms is DNA, but in some viruses is RNA. It
can also occur by rearrangement of an organism's
chromosomes. Specific mutations due to a change in DNA
sequence have been recognized as causing certain
specific hereditary diseases. Certain processes which
produce variation in the genotype of an organism, such
as sexual mixing of chromosomes in offspring, or
artificially induced recombination or introduction of
novel genetic material into an organism, are not
referred to as mutation.
[Webster 1913 Suppl. PJC]

4. (Biol.) a variant strain of an organism in which the
hereditary variant property is caused by a mutation[3].
[Webster 1913 Suppl.]

64 Moby Thesaurus words for "mutation":
ablaut, acoustic phonetics, alteration, altering, anomaly,
articulatory phonetics, avatar, betacism, catabolism, catalysis,
change, changing, consubstantiation, departure, deviant, deviation,
displacement, evolution, evolving, gradation, heterotopia,
innovation, metabolism, metagenesis, metamorphism, metamorphosing,
metamorphosis, metastasis, metathesis, metempsychosis,
modification, modifying, morphophonemics, mutant, mutated form,
novelty, orthoepy, permutation, phonetics, phonology,
reincarnation, rhotacism, sound shift, sport, transanimation,
transfiguration, transfigurement, transformation, transforming,
transformism, translation, translocation, transmigration,
transmogrification, transmutation, transmuting, transposition,
transubstantiation, turn, umlaut, variant, variation, varying,
vicissitude

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  • Mutation | Definition, Causes, Types, Facts | Britannica
    mutation, an alteration in the genetic material (the genome) of a cell of a living organism or of a virus that is more or less permanent and that can be transmitted to the cell’s or the virus’s descendants
  • Mutation - Wikipedia
    In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA [1] Viral genomes contain either DNA or RNA
  • Mutations - Understanding Evolution
    For example, the yellow color on half of a petal on this red tulip was caused by a somatic mutation The seeds of the tulip do not carry the mutation Cancer is also caused by somatic mutations that cause a particular cell lineage (e g , in the breast or brain) to multiply out of control Such mutations affect the individual carrying them but are not passed directly on to offspring Photo from
  • Mutation
    A mutation is a change in a DNA sequence Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses
  • What is a Mutation? Understanding DNA Changes and Their . . .
    To understand mutation is to appreciate both the fragility and resilience of life It reveals how a single letter change in a molecule can alter the course of history—or the fate of an individual





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