MUTATION


Meaning of MUTATION in English

noun

COLLOCATIONS FROM CORPUS

■ ADJECTIVE

deleterious

Now, suppose that deleterious mutations reduce survival below this optimal value.

Senescence of clones is probably caused by the accumulation of deleterious mutations .

Furthermore, the total rate of production of deleterious mutations and their pattern of age-specificity are unknown.

Suppose now that deleterious mutations are age-specific.

different

Andean vultures become avid for the life-giving molecule with quite a different set of mutations .

Over 40 different mutations of the phenylalanine hydroxylase gene have been identified.

Ironically, a similar belief prevails today, in a slightly different mutation .

This is a worthwhile approach, though one should bear in mind that different mutagens give qualitatively different kinds of mutation .

genetic

Fears that radiotherapy would cause genetic mutations leading to handicaps in offspring appear to be groundless, according to studies among 3,000 survivors.

But in the 1980s, scientists found that a genetic mutation was responsible.

Variations occur within a population, explicable as genetic mutations or the results of mixing of genetic material.

On the other hand, most cases of the disease seem to develop without genetic mutations , Gibbs said.

With enough genetic mutations at hand, the behaviour could perhaps have evolved independently in each species.

Some people may have a predisposition to the genetic mutations that lead to disease.

Evolution requires genetic change, mutation .

Trichloroethene, a probable human carcinogen, can cause liver damage and genetic mutations in both human and animal populations.

new

Long-inbred populations might be useful for assessing the effects of new mutations .

It is people like Dawkins who are the new genetic mutations which will spread only if they have superior survival value.

In outbred populations, selection acts on new mutations mainly through their heterozygous effects.

It presses new mutations into service as they arise and is just as ready to make do with what is already around.

When necessary, bacteria cheat to ensure a supply of new mutations .

To begin with, this was the only such pattern in existence, but then a new mutation arose.

Whether his fainting goats were a new mutation or part of an older breed remains unclear.

In splurge-weed, the new mutation can arise in any cell, in any branch of the plant.

random

When they seemed to resemble each other rather too closely, he introduced random mutations in the offspring.

The genes that cause the elaborate ornament or long tail to appear are subject to random mutation .

Our random mutation is essential because it is unnecessary.

The more elaborate the ornament, the more likely that a random mutation will make the ornament less elaborate, not more.

We want them to emerge solely as a result of cumulative selection of random mutations .

It follows that some process other than random mutation and selection must be involved.

■ NOUN

gene

K-ras gene mutations , by contrast with p53, clearly occur at an earlier stage in the neoplastic sequence.

Other workers have found ras gene mutations in between 39% and 47% of colorectal cancers.

Enough premalignant cells are present in the bulk of stool to permit the analysis of tumour suppressor gene mutations by this technique.

point

Loss of tumour suppressor function requires inactivation of both alleles, usually by chromosomal deletion or point mutation , or both.

The use of immunohistochemical staining as a marker of point mutation has been critically reviewed by Wyndord-Thomas.

Nineth five percent of large bowel cancers showing loss of heterozygosity for 17p alleles also contain a point mutation .

Thus, both of the point mutations characterized here would be expected to eliminate kinase activity of the proposed atk protein product.

Apart from point mutation , another way in which oncogenes can be activated is by over expression.

rate

If mutagens like cosmic rays are present then all normal mutation rates are boosted.

It strives for a mutation rate of zero.

For the last 20 years researchers have been able to calculate genome sizes and mutation rates .

By far the shakiest part of the calculation is the average mutation rate .

Moreover, mutation rates seem to change with the physiological state of the organism.

Yes, this is the inverse of what is known as the mutation rate , and it can be measured.

That is, the rate of substitution equals the neutral mutation rate.

They are free to evolve at the mutation rate .

■ VERB

cause

Fears that radiotherapy would cause genetic mutations leading to handicaps in offspring appear to be groundless, according to studies among 3,000 survivors.

Tests have shown them to restrict growth and cause mutations in micro-organisms.

contain

Each digestion included a positive colorectal carcinoma or adenoma control known to contain a mutation at codon 12.

Nineth five percent of large bowel cancers showing loss of heterozygosity for 17p alleles also contain a point mutation .

find

Other workers have found ras gene mutations in between 39% and 47% of colorectal cancers.

But in the 1980s, scientists found that a genetic mutation was responsible.

show

If this shows a lethal mutation it is classified as a presumed mammalian mutagen.

EXAMPLES FROM CORPUS

A minor mutation should be deemed an eccentricity and nothing more.

A second bug experienced a mutation that allowed it to make use of the acetate excreted from the first.

By far the shakiest part of the calculation is the average mutation rate.

For the last 20 years researchers have been able to calculate genome sizes and mutation rates.

If mutagens like cosmic rays are present then all normal mutation rates are boosted.

Living organisms have a similar tradeoff in deciding how much mutation and innovation is needed to keep up with a changing environment.

Previously, disease-causing mutations have been linked to rare or incurable disorders, providing often debatable benefits to small numbers of people.

The other mode depends on occasional small mutations, like the changes in the parameters of protozoa.

Longman DOCE5 Extras English vocabulary.      Дополнительный английский словарь Longman DOCE5.