D – F

Dicentric chromosome
Chromosome with two cetromeres is called as dicentric chromosome.
Species with two cotyledon are called as dicotyledonous species or dicots or dicotyledons.
Dihybrid is the progeny of a cross between two individuals which differ for two characters (contrasting character) i.e. heterozygous for two loci.
Dihybrid Cross
Dihybrid cross is a cross between two individuals which differ for two characters i.e. heterozygous for two loci.
Dispersive replication
In this model there is fragmentation of parental strand and intermixing of pieces of parent helix with newly synthesized pieces to form new daughter molecule.
DNA is the chemical, mostly inside the nucleus of a cell that carries the hereditary or genetic information generation after generation.
DNA Replication
DNA replication is the complex process in which DNA unwinds and makes an identical copy of a section of double-stranded DNA, using existing parental DNA as a template for the synthesis of new daughter DNA strands.
If phenotype of the organism is determined by one of the alleles by completely hiding the expression of an alternate allele, then that allele is said to be dominant. The phenomenon is called as dominance.
Dominant Negative
Some loss-of-function mutations are dominant. These are referred as dominant negative.
Dormancy is the failure of fully developed, mature, viable seed to germinate even under favorable physical conditions (like moisture and temperature).
Dormant seed
The seed with dormancy is termed as dormant seed.
Economic heterosis
When heterosis is estimated over standard commercial hybrid it is called as economic heterosis.
Embryogenesis is the process by which embryo forms and develops, from zygote, pollen or bipolar structures from somatic cells that parallel the developmental path of zygotic embryos.
Endosperm is a triploid (albumin) tissue found in the seeds of most of the flowering plants.
Endospermic seed
Seed with a special food storage tissue (an endosperm) at maturity is called as endospermic seed.
Epicotyl is the stem of a seedling or embryo between the cotyledons and the first true leaf.
Epigeal cotyledon
Cotyledons which expands on the germination of the seed, throwing off the seed shell, pushed above soil surface and become photosynthetic is called as epigeal cotyledon.
Epigeal germination
When cotyledons pushed above soil surface due to rapid elongation of hypocotyls then it is called as epigeal germination.
Euchromatin are portions of chromosome with lightly packed DNA, partially condensed and stain lightly.
Condition in which somatic cell have one or more complete genomes which may be identical with or distinct from each other is called as euploidy.
Ex-albuminous seed
Seeds with no endosperm (a special food storage tissue) at maturity are termed exalbuminous seeds.
F1 generation
First filial generation produced by crossing two parents.
F2 generation
Second filial generation produced by selfing or intercrossing in F1.
Mendel called “factors” to what we now call genes.
Facultative heterochromatin
Type of heterochromatin whose DNA is not permanently inactive and follow periodic dispersal is called as facultative heterochromatin.
Foundation Seed
Foundation seed is the progeny of breeder seed.