Variation

Variation
In genetics, deviation in characters in an individual from those typical of the group to which it belongs, also, deviation in characters of the offspring from those of its parents.

Genetic variation, variation in alleles of genes, occurs both within and among populations. Genetic variation is important because it provides the 'raw material' for natural selection.
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Genetic Variation
Genetic variation refers to diversity in gene frequencies. Genetic variation can refer to differences between individuals or to differences between populations.

variation in a population that falls into two or more nonoverlapping classes
Source: Jenkins, John B. 1990. Human Genetics, 2nd Edition. New York: Harper & Row
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Variation that falls into discrete categories (eg the colour of garden peas).
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ...

Antigenic variation
Antigenic variation is the process by which an infectious organism alters its surface proteins in order to evade a host immune response.

Variations."Accessory slips of origin from the talus and navicular, or from the external cunei-form and third metatarsal bones to the second slip of the muscle, and one from the cuboid to the third slip have been observed.

Variation
For many traits that occur in a population, individuals are often not all identical.

variation
Diversity among the members of a population. Variation among individuals can exist at many levels, including genetic, physiologic and behavioral.
vas deferens pl. vasa deferentia ...

Variation
Since its inception, GDB has been a repository for polymorphism data, with more than 18,000 polymorphisms now in GDB.

Variation. Differences in the frequency of genes and traits among individual organisms within a population.

Phase variation
A mechanism which results in variable expression of surface antigens. An example is the switch between H1 and H2 flagellar antigens by an invertable switch in Salmonella.

GENETIC VARIATION
Sometimes your skeletal system and the tissues of your skeleton can have problems. Some genetic diseases cause individuals to grow excessive large and thick bones.

Variation Within and Among Human Populations
Out of Africa?
Neaderthals in Our Gene Pool?

Variation in alleles among members of the same species.
Alternative splicing
Different ways of combining a gene's exons to make variants of the complete protein ...

variation Differences among individuals of a group or species that cannot be ascribed to age, sex, or position in the life cycle.
Vas L. Duct or vessel.

variation in the exact splice point and
the introduction of N nucleotides
both of which increase the diversity of CDR3.

A variation on Case 4 is when there are only two genotypes known for the children, and both parental genotypes must be predicted. Panel (a) - Marilyn and Janet are 15, 16 at the locus D3S1358. Buddy and Dick are 18, 18.

Genetic variation between individuals in DNA fragment sizes resulting from a difference in DNA sequence that affects the recognition sequence for restriction enzymes when cut by specific restriction enzymes.

Without variation (which arises from mutations of DNA molecules to produce new alleles) natural selection would have nothing on which to act. A population is a group of individuals living in the same geographical area and sharing a common gene pool.

Several variations have been developed for specific needs. May be combined with reverse transcription of mRNA to cDNA to amplify an mRNA so called RT-PCR.
Related Terms:
Base sequence
The order of nucleotide bases in a DNA molecule.

Genetic variation has two components: allelic diversity and non- random associations of alleles. Alleles are different versions of the same gene. For example, humans can have A, B or O alleles that determine one aspect of their blood type.

Possessing a variation in antigenic structure, as determined by monoclonal or molecular techniques ...

continuous variation Occurs when the phenotypes of traits controlled by a single gene cannot be sorted into two distinct phenotypic classes, but rather fall into a series of overlapping classes. PICTURE ...

POLYMORPHISM - Variation within a DNA or RNA sequence.
POLYNUCLEOTIDE KINASE - Enzyme which catalyzes the transfer of the terminal phosphate of ATP to 5' hydroxyl termini of polynucleotides, either DNAor RNA. Usually derived from T4 bacteriophage.

Mutations Variations that alter the meaning of the genetic message; required for evolution.

Genetic variation -- a phenotypic variance of a trait in a population attributed to genetic heterogeneity.

Allele: A known variation (version) of a particular gene. Formerly called allelomorph.
Allelic association: see linkage disequilibrium.

Random variation in gene frequency from one generation to another. Genetic engineering. The manipulation of an organism's genetic endowment by introducing or eliminating specific genes through modern molecular biology techniques.

Biodiversity: The total variation in life, including the number of species, the degree of genetic variation within species, the different types of ecosystems, and the all ecosystem functions.

The finding that APOE (the gene encoding apolipoprotein E) polymorphic variation was associated with an altered risk of developing Alzheimer's disease (AD) was a significant advance and immediately prompted a search for the mechanisms responsible for ...

We now know that inherited variation comes about through mutation, random assortment of chromosomes and genes in meiosis, sexual reproduction where two parents contribute (different) genes to the offspring, ...

Stable isotopes are atomic variations of elements that are stable over long periods of time, meaning they do not radioactively decay. Several elements, like oxygen and carbon, have several stable forms.

As the bacterium is exposed to 50° C, she will respond through many spontaneous mechanisms for defending herself from the hostile variation in her environment to continue being alive.

Polymorphism Genetic variation occurring in a population so that at least two alleles are present at a frequency of 1% or gretaer.

AFLP Amplified Fragment Length Polymorphism (AFLP) methods are used to detect multiple sequence variations in a single sample.

Genetics is the science of genes, heredity, and the variation of organisms. In modern research, genetics provides important tools in the investigation of the function of a particular gene, e.g. analysis of genetic interactions.

Restriction fragment length polymorphisms (RFLP) are variation in DNA fragment banding patterns of electrophoresed restriction digests of DNA from different individuals of a species.

With all the possible variations, it would be very difficult to find two people with the exact same hair color, thickness, and so on. What about your eyes. What color are they? How big are they?

Biodiversity: The variation in life on Earth reflected at all levels, from various ecosystems and species, to the genetic variation within a species. See also ecosystem diversity, species diversity, genetic diversity.

Restriction fragment length polymorphism (RFLP): Variation between individuals in DNA fragment sizes cut by specific restriction enzymes; polymorphic sequences that result in RFLPs are used as markers on both physical maps and genetic linkage maps.

Different alleles produce variation in inherited traits such as hair colour or blood type. In an individual, one form of the allele (the dominant one) may be expressed more than another form (the recessive one). [Talking Glossary] ...

Cline gradual geographical variation in some phenotypic character
(clin = slope‚ lean)
Clitoris female erectile structure that is homologous to the penis
(clitor = to enclose) ...

Budding viruses are often exactly like the original particle that initially infected the host. In the case of HIV, however, the resulting viruses exhibit a range of variations which makes treatment difficult.
Return to Overview of HIV Infection.

Any warm-blooded animal (mammal or bird that can maintain its body temperature within a narrow range, usually above that of its surroundings despite large variations in environmental temperature.

As depicted, collenchyma cells occur in aggregates just beneath the epidermis and possess thicker primary cell walls than parenchyma cells. The thickness of the walls, however, does exhibit notable variation.

See also: Human, Organ, Trans, DNA, Sequence