noun
hemizygote
Genetics term for a diploid organism having only one allele at a given locus, as in X-linked genes in males.
ヒトの男性はX染色体上の遺伝子についてヘミ接合体である。
Human males are hemizygous for genes on the X chromosome.
Heterozygote: having two different alleles at a locus, while hemizygote has only one allele present.
From English 'hemizygote', combining 'hemi-' (half) and 'zygote'. The Japanese form uses katakana ヘミ for the prefix and kanji 接合体 for 'zygote'.