Semidominant: an alleleplugin-autotooltip__default plugin-autotooltip_bigAllele: a version of a gene. Alleles of a gene are different if they have differences in their DNA sequence. $X$ is semidominant if a $\frac{X}{X}$ homozygousplugin-autotooltip__default plugin-autotooltip_bigHomozygous: a state for a diploid organism wherein the two alleles for a gene are identical to each other. individual is fully mutantplugin-autotooltip__default plugin-autotooltip_bigMutant: an individual that has a different phenotype than wildtype and likely contains one more mutations that cause this difference., a $\frac{X}{x}$ individual is partially or weakly mutantplugin-autotooltip__default plugin-autotooltip_bigMutant: an individual that has a different phenotype than wildtype and likely contains one more mutations that cause this difference., and a $\frac{x}{x}$ individual is wildtypeplugin-autotooltip__default plugin-autotooltip_bigWildtype: a reference strain of an organism that scientists operationally define as “normal” to which mutants are compared. Not to be confused with wild organisms..