Wilhelm Johannsen

Wilhelm Ludvig Johannsen
Born	(1857-02-03)3 February 1857 Elsinore, Denmark
Died	11 November 1927(1927-11-11) (aged 70) Copenhagen, Denmark
Nationality	Danish
Alma mater	University of Copenhagen
Known for	proving the constancy of the genome Coining gene, genotype and phenotype
Scientific career
Fields	Genetics Plant physiology
Institutions	University of Copenhagen

Wilhelm Johannsen (3 February 1857 – 11 November 1927) was a Danish pharmacist, botanist, plant physiologist, and geneticist. He is best known for coining the terms gene, phenotype and genotype, and for his 1903 "pure line" experiments in genetics.