| zygotic lethal gene | <genetics> A mutated or otherwise defective gene at embryonic or larval stages. (06 May 1997) |
|---|---|
| lethal | Deadly, fatal. Origin: L. Lethalis, from lethum = death (18 Nov 1997) |
| lethal coefficient | <microbiology> That concentration of disinfectant that kills bacteria at 20-25°C in the shortest period of time. (05 Mar 2000) |
| lethal dose | <pharmacology> The amount, or dosage, of a toxin necessary to cause death. (16 Mar 1998) |
| lethal dose 50 | <pharmacology> The amount, or dosage, of a toxin necessary to kill 50% of the experimental subjects. (16 Mar 1998) |
| lethal dwarfism | Dwarfism leading to intrauterine or neonatal death. (05 Mar 2000) |
| lethal factor | A disorder that prevents effective reproduction by those affected; e.g., Klinefelter syndrome. (05 Mar 2000) |
| lethal gene | A gene that produces a genotype that leads to death of the organism before reproduction is possible or that precludes reproduction; for a recessive gene the homozygous or hemizygous state is lethal. (05 Mar 2000) |
| lethal midline granuloma | Destruction of the nasal septum, hard palate, lateral nasal walls, paranasal sinuses, skin of the face, orbit and nasopharynx by an inflammatory infiltrate with atypical lymphocytic and histiocytic cells; presumably a form of lymphoma in most cases. An obsolete term for polymorphic reticulosis. Synonym: granuloma gangrenescens, malignant granuloma, midline malignant reticulosis granuloma. (05 Mar 2000) |
| lethal mutation | <genetics, molecular biology> Mutation that eventually results in the death of an organism carrying the mutation. (18 Nov 1997) |