Terms used on the Crop Genebank Knowledge Base.
| Term | Definition |
|---|---|
| Haploid |
A single set of chromosomes (half the full set of genetic material), present in each egg and sperm cell of animals and in each egg and pollen cell of plants (Gk. haploos, single). (cf. Diploid) |
| Haplotype |
A specific allelic constitution at a number of loci within a defined linkage block. |
| Hard seeds |
Seeds that fail to imbibe and germinate when placed in a moist medium because they are impermeable to water. |
| Hardy-Weinberg equilibrium |
The stable frequency distribution of genotypes AA Aa and aa in the proportions p??? 2pq and q??? respectively (where p and q are the frequencies of the alleles A and a) that is a consequence of random mating in the absence of mutation migration natural selection or random drift. |
| Heterotic groups |
Groups of germplasm that when crossed maximize heterosis. Heterosis is a phenomenon that heterozygotes in a population often have higher fitness than the homozygotes. |
| Heterozygote |
A diploid individual that has different alleles at one or more genetic loci (Gk. heteros, other) (cf. Homozygote) |
| Homologous |
Characters that arise by common descent. |
| Homoplasy |
A term in cladistic analysis that refers to the proportion of parallelisms and reversals on a phylogenetic tree. Also used for different DNA fragments of identical size that cannot be distinguished by gel electrophoresis. |
| Homozygote |
A diploid individual that has identical alleles at one or more genetic loci (Gk. homos, same) (cf. Heterozygote) |
| HRIGRU - Warwick |
Genetic Resources Unit of Warwick HRI University of Warwick UK |
Glossary open source software by M. Brampton