| hybrid sterility | <genetics, zoology> The inability of a hybrid to produce viable offspring. Whether an animal hybrid is sterile or fertile depends mainly on how closely its two parent species are related. For example: mules (which are hybrids between male donkeys and female horses) are usually sterile, while hybrids between domestic dogs and wolves are fertile (hybrids between wolves and foxes are also fertile, but hybrids between dogs and foxes are sterile). (09 Oct 1997) |
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| hybrid swarm | A group of morphologically distinctive individuals which results from the creation of hybrids between two parent species, then the backcrossing of the offspring to members of the parent species and the interbreeding among the hybrid individuals. (09 Oct 1997) |
| hybrid vigor | The adaptive superiority of heterozygous genotypes with respect to one or more characters in comparison with the corresponding homozygotes. (12 Dec 1998) |
| somatic hybrid | Heterokaryon formed between two somatic cells, usually from different species. See: somatic cell genetics. (18 Nov 1997) |
| SV40-adenovirus hybrid | A virion consisting of SV40 genetic material encased in an adenovirus capsid. (05 Mar 2000) |
| DNA-RNA hybrid | Double-stranded polynucleic acids in which one strand is DNA and the other strand is the complementary RNA; formed during transcription and during multiplication of oncogenic RNA viruses. (05 Mar 2000) |
| upper hybrid waves | <radiobiology> Similar to lower hybrid waves, but at a higher frequency. Not truly propagating waves, but plasma oscillations. (09 Oct 1997) |
| fusion-fission hybrid | <radiobiology> Proposed nuclear reactor relying on both fusion and fission reactions. A central fusion chamber would produce neutrons to induce fission in a surrounding blanket of fissionable material. The neutron source could also be used to convert other materials into additional fissile fuels (breeder hybrid). Safer than a plain fission reactor because the fission fuel relies on the fusion neutrons, and therefore cannot achieve criticality. On the other hand, hybrids are more complex because of the fusion power core, and still generate fission's radioactive byproducts. But a fusion-fission hybrid could be more economical and have less stringent technical requirements than a pure fusion reactor. (05 Jan 1998) |
| lower hybrid waves | <physics> Electrostatic ion oscillations at a frequency intermediate to the electron extraordinary wave (high frequency) and the magnetosonic wave (low frequency). (09 Oct 1997) |
| relative molecular mass | The sum of the atomic weight's of all the atoms constituting a molecule; the mass of a molecule relative to the mass of a standard atom, now 12C (taken as 12.000). Relative molecular mass (Mr) is the mass relative to the dalton and has no units. See: atomic weight. Synonym: molecular mass, molecular weight ratio, relative molecular mass. (05 Mar 2000) |
| gram-molecular weight | Molecular weight expressed in grams. Compare: mole. (05 Mar 2000) |
| cloning, molecular | The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells. (12 Dec 1998) |
| models, molecular | Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures. (12 Dec 1998) |
| molecular | <chemistry> Of, pertaining to or composed of molecules: a very small mass of matter. (18 Nov 1997) |
| molecular behaviour | <psychology> Behaviour described in small response units rather than larger ones; a specific response. Compare: molar behaviour. (05 Mar 2000) |