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An image of multiple chromosomes, taken from many cells. Plant genetics is the study of genes, genetic variation, and heredity specifically in plants. [1] [2] It is generally considered a field of biology and botany, but intersects frequently with many other life sciences and is strongly linked with the study of information systems.
Trisomy 21 – Down syndrome, an example of a polysomy at chromosome 21. Polysomy is a condition found in many species, including fungi, plants, insects, and mammals, in which an organism has at least one more chromosome than normal, i.e., there may be three or more copies of the chromosome rather than the expected two copies. [1]
An example of a botanical genetic polymorphism is heterostyly, in which flowers occur in different forms with different arrangements of the pistils and the stamens. The system is called heteromorphic self-incompatibility , and the general 'strategy' of stamens separated from pistils is known as herkogamy .
Double-flower forms often arise when some or all of the stamens in a flower are replaced by petals. These types of mutations, where one organ in a developing organism is replaced with another, are known as homeotic mutations. They are usually recessive, although the double flower mutation in carnations exhibits incomplete dominance. [9]
Random mutations are the ultimate source of genetic variation. Mutations are likely to be rare, and most mutations are neutral or deleterious, but in some instances, the new alleles can be favored by natural selection. Polyploidy is an example of chromosomal mutation. Polyploidy is a condition wherein organisms have three or more sets of ...
Somaclonal variation is the variation seen in plants that have been produced by plant tissue culture. Chromosomal rearrangements are an important source of this variation. . The term somaclonal variation is a phenomenon of broad taxonomic occurrence, reported for species of different ploidy levels, and for outcrossing and inbreeding, vegetatively and seed propagated, and cultivated and non ...
Mutation breeding, sometimes referred to as "variation breeding", is the process of exposing seeds to chemicals, radiation, or enzymes [1] [2] in order to generate mutants with desirable traits to be bred with other cultivars. Plants created using mutagenesis are sometimes called mutagenic plants or mutagenic seeds.
Autosomal dominant and autosomal recessive inheritance, the two most common Mendelian inheritance patterns. An autosome is any chromosome other than a sex chromosome.. In genetics, dominance is the phenomenon of one variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome.