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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.
Gene-for-gene relationships are a widespread and very important aspect of plant disease resistance. Another example can be seen with Lactuca serriola versus Bremia lactucae. Clayton Oscar Person [6] was the first scientist to study plant pathosystem ratios rather than genetics ratios in host-parasite systems. In doing so, he discovered the ...
The following is a list of genetic disorders and if known, type of mutation and for the chromosome involved. Although the parlance "disease-causing gene" is common, it is the occurrence of an abnormality in the parents that causes the impairment to develop within the child. There are over 6,000 known genetic disorders in humans.
Mutations leading to an attenuated phenotype were mapped by amplification of adjacent regions to the IS1096 sequences and compared with the published M. tuberculosis genome. In this instance transposon mutagenesis identified 13 pathogenic loci in the M. tuberculosis genome which were not previously associated with disease. [ 10 ]
In the neutral theory of molecular evolution, neutral mutations provide genetic drift as the basis for most variation at the molecular level. In animals or plants, most mutations are neutral, given that the vast majority of their genomes is either non-coding or consists of repetitive sequences that have no obvious function ("junk DNA"). [58]
Around 65% of people have some kind of health problem as a result of congenital genetic mutations. [7] Due to the significantly large number of genetic disorders, approximately 1 in 21 people are affected by a genetic disorder classified as "rare" (usually defined as affecting less than 1 in 2,000 people). Most genetic disorders are rare in ...
The distinction between sectorial, mericlinal and periclinal plant chimeras is widely used. [36] [37] Periclinal chimeras involve a genetic difference that persists in the descendant cells of a particular meristem layer. This type of chimera is more stable than mericlinal or sectoral mutations that affect only later generations of cells. [38]
Compound heterozygosity reflects the diversity of the mutation base for many autosomal recessive genetic disorders; mutations in most disease-causing genes have arisen many times. This means that many cases of disease arise in individuals who have two unrelated alleles, who technically are heterozygotes, but both the alleles are defective.