| A | B |
|---|
| ascospores | ordered products of fungal meioses enclosed in a sac |
| ascus | sac enclosing ordered products of fungal meisoses |
| centimorgan | 1% recombination |
| chiasmata | cross-overs formed during homologous recombination |
| coefficient of coincidence | ratio of observed to expected double recombinants |
| double crossovers | two chromosome breakages occur between two genes |
| genetic linkage | alleles from two genes inherited as a unit |
| genetic markers | genes for easily detectable traits to monitor structures |
| interference | crossovers in one region affect crossovers in another region of chromosomes |
| linkage group | several genes that tend to be inherited as a unit |
| locus | physical location of a gene on a chromosome |
| mapping | determining location and/or order of genes on a chromosome |
| map unit | 1% recombination or 1 centimorgan |
| nonparental ditype | combination of any two traits not seen in the P generation |
| ordered tetrad analysis | examination of meisosis in ascomycetes |
| parental ditype | combination of two traits seen in the first generation of a genetic cross |
| physical markers | actual DNA landmark such as chromosome band or restriction endonuclease site |
| recombinant | not showing a parental ditype |
| recombination | movement of DNA from one chromosome to another |
| recombination frequency | proportion of individuals showing nonparental ditype |
| terminalization | movement of cross-over sites toward ends of chromosomes |
| tetrad | four products of any meiosis |
| two point cross | figuring linkage relationship by examining two traits at a time |
| three point cross | figuring linkage relationships between three traits simultaneously |
