QDenotes the longer of the two chromosome arms, e.g. human 10q is the long arm of human chromosome 10.
q-beta replicaseA viral RNA polymerase secreted by a bacteriophage that infects E. coli. It has the property of being able to copy RNA sequences at a rapid rate.
QSARAbbreviation for quantitative structure-activity relationship.
quadrivalentA chromosome configuration visible in late prophase and metaphase of the first meiotic division, where four chromosome s are linked by chiasmata.
quadruplexThe inheritance of alleles in autotetraploids. A genotype AAAa will produce gametes AA, Aa in the ratio 3:1.
qualitative traitA trait that shows discontinuous variation - i.e. individuals can be assigned to one of a small number of discrete classes.
quantitative geneticsThe area of genetics concerned with the inheritance of quantitative traits that show continuous variation, as opposed to qualitative trait s.
quantitative inheritanceInheritance of measurable traits that depend on the cumulative action of many genes and/or involve a significant proportion of non-genetic determination.
quantitative structure-activity relationship(Abbreviation QSAR). A computer modelling technique that enables the prediction of the likely activity of a molecule before it is synthesized.
quantitative traitA measurable trait that shows continuous variation (e.g. height, weight, colour intensity, etc.) - i.e.
quantitative trait locus(Abbreviation: QTL). A locus where is associated with variation in a quantitative trait.
quantum speciationThe rapid formation of new species, primarily by genetic drift.
quarantineIsolation for a period after arrival in a new location, to allow any pre-existing disease symptoms to appear.
quaternary structureA level of protein structure where several individual molecules assemble together and form a functional cluster.
quiescentA temporary suspension or reduction in the rate of activity or growth, while retaining the potential to resume prior activity.