Intergeneric
A cross between two different genera.

Intergenic regions
DNA sequences located between genes; they comprise a large percentage of a genome and have no known function.

Intergenic
Between two genes; e.g. intergenic DNA is the DNA found between two genes. The term is often used to mean non functional DNA (or at least DNA with no known importance to the two genes flanking it). Alternatively, one might speak of the "intergenic distance" between two genes as the number of base pairs from the poly A site of the first gene to the cap site of the second. This usage might therefore include the promoter region of the second gene.

Interphase.
The stage in the cell cycle when the cell is not dividing; the stage follows telophase of one division and extends to the beginning of prophase in the next division. DNA replication occurs during this stage.

Intersex
An organism displaying a mixture of male and female attributes.

Interspecific
Between two different species, e.g., an interspecific cross is a cross between two species.

Intragenic  complementation
Complementation that occurs between two mutant alleles of a gene; common only when the product of the gene functions as a homomultimer.

Intraspecific
Within a species or its populations, including subspecies, such as an intraspecific cross, or variation.

Introgression
The introduction of new gene(s) into a population by crossing, between two populations, followed by repeated backcrossing to that population while retaining the new gene(s).