Phenotype of an individual can be understood to consist in the set of all the properties that the particular individual exhibits. Some of these properties are genetically determined, i.e. their occurrence is determined by the presence of specific genetic information in the genome of the particular individual. Other properties, such as behaviour in an environment with a temperature of 3000 oC, are not genetically determined but follow from the properties of the substances from which the bodies of organisms are composed. A great many properties are simultaneously determined genetically and by the environment. In this case, the occurrence of certain properties is dependent, e.g., on the character of the external environment in which the particular individual occurs, or on the internal environment of the particular organism, which parameter is, once again, frequently determined by the overall genotype of the given individual.