ROSA26 is a locus used for constitutive, ubiquitous gene expression in mice. In all three classes, constitutive and inducible forms exist. Oxygenases consist of both constitutive and inducible isozymes (HO-1, HO-2). It is associated with both facultative and constitutive heterochromatin. Particularly, H3K9me3 is highly correlated with constitutive heterochromatin. A clear distinction is made between explanatory and constitutive approaches when classifying international relations theories. The internal contact forces are related to the body's deformation through constitutive equations. Plant defenses can be classified generally as constitutive or induced. The equations specifying this response are called constitutive relations. The regions that stain darker are regions of constitutive heterochromatin. Histone modifications are one of the main ways that the cell condenses constitutive heterochromatin. These relations between and are examples of constitutive equations. The system of differential equations is completed by a set of linear algebraic constitutive relations. Psychoanalysis is a constitutive element of critical theory. Constitutive and induced defenses are both found in the bark.