The male is hemizygote for the X-chromosome. (he has only one copy of the chromosome X).

Refers to a cell, organism, or individual with only one of a pair of genes for a specific trait. This term is often used to describe males who inherit one copy of an X-linked disease trait. It may also refer to the state in which genetic material is deleted from one member of a chromosomal pair.

An animal with a transgene insertion on one chromosome of a homologous pair, rather than on each of the two homologous chromosomes (homozygote).