| MLC | 1) Minimal Lethal Concentration 2) Mixed Lymphocyte Culture |
|---|---|
| PLD | POtentially Lethal Damage |
| SLD | Sub-Lethal Damage |
| CELO | chick embryonal lethal orphan [virus] |
| DL | danger list; De Lee [catheter]; deep lobe; developmental level; difference limen; diffusion lung [ca... |
| dominant lethal trait | Trait, expressed in the phenotype if present in the genotype, that precludes having descendants. All such cases are necessarily sporadic and must represent new mutations as the usual methods of classical genetics provide no means of demonstrating any genetic component whatsoever, except for tenuous arguments such as advanced paternal age. Molecular biology may help although the methods may be tedious; if there is an epistatic gene that may mask the trait, the logic is more tractable, though complex. (05 Mar 2000) |
|---|---|
| lethal | Deadly, fatal. Origin: L. Lethalis, from lethum = death (18 Nov 1997) |
| lethal coefficient | <microbiology> That concentration of disinfectant that kills bacteria at 20-25캜 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 equivalent | A combination of selective effects that on average have the same impact on the composition of the gene pool as one death; e.g., two carriers at 50% risk of dying would be the lethal equivalent of one carrier at 100% risk, in the population genetics of recessive traits lethal equivalent is expressed as twice the sum of the expected number of deaths ascribable to the genetic load. Expression used of the genetic load of recessive genes in heterozygous state that if in homozygous state would cause death or carry a risk of death. The expected number of deaths from all such genes is expressed in lethal equivalent. (05 Mar 2000) |
| lethal factor | A disorder that prevents effective reproduction by those affected; e.g., Klinefelter syndrome. (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) |
| allelic gene | See: allele, dominance of traits. (05 Mar 2000) |
| antibiotic resistance gene | Genes in a microorganism which confer resistance to antibiotics, for example by coding for enzymes which destroy it, by coding for surface proteins which prevent it from entering the microorganism, or by being a mutant form of the antibiotic's target so that it can ignore it. (09 Oct 1997) |
| autosomal gene | A gene located on any chromosome other than the sex chromosomes (X or Y). (05 Mar 2000) |
| bicoid gene | A group of genes which are important to the proper development of the head and thorax in the embryo of the fruit fly Drosophila melanogaster. (09 Oct 1997) |
| BRCA1 breast cancer susceptibility gene | This mutated (changed) version of the BRCA1 gene makes a person susceptible to developing breast cancer. (12 Dec 1998) |