BioConcepts

heterozygousheterozygot (ger.)

• Having different alleles at one or more genetic loci. (OED 2011)
  category gene see also homozygous

  1902

  [the zygote formed by the union of a pair of opposite allelomorphic gametes, we shall call a heterozygote.

  Bateson, W. & Saunders, E.R. (1902). The facts of heredity in the light of Mendel’s discovery. Rep. Evol. Comm. Roy. Soc. I, 125-160: 126.]

  1902

  This Aa is the hybrid or ‘mule’ form, or as I have elsewhere called it, the heterozygote, as distinguished from AA or aa the homozygotes. […] it would a priori seem most probable that one sex is heterozygous and the other homozygous

  Bateson, W. (1902). Mendel’s Principles of Heredity: 23; 166.

  1902

  [when the varieties A and B are crossed together, the heterozygote, AB, produces games bearing the pure A character and the pure B character.

  Bateson, W. (1902). The problems of heredity and their solution (Scientific Papers, vol. 2, Cambridge 1928, 4-28): 23.]

  1982

  heterozygous Having two different alleles at a given locus of a chromosome pair; heterozygosis, heterozygosity; cf. homozygous.

  Lincoln, R.J., Boxshall, G.A. & Clark, P.F. (1982). A Dictionary of Ecology, Evolution and Systematics: 113.