Mendelian Expression of Genes in Diploid Organisms
A gene is only a DNA code sequence; the slightly different variations of that sequence are called alleles. Alleles can be significantly different and produce different product RNAs.
Combinations of different alleles thus go on to generate different traits through the information flow charted above. For example, if the alleles on homologous chromosomes exhibit a "simple dominance" relationship, the trait of the "dominant" allele shows in the phenotype.
Gregor Mendel pioneered modern genetics. His most famous analyses were based on clear-cut traits with simple dominance. He determined that the heritable units, what we now call genes, occurred in pairs. His tool was statistics: long before the molecular model of DNA was introduced by James D. Watson and Francis Crick.
He is also known to have 'cheated' on his experiments, removing outliers and generally 'tidying' datasets - statistics, and repeating the experiments, shows that his results were just 'too perfect', a point first noted by the Godfather of statistics, RA Fisher, in 1936: http://www.cs.brown.edu/courses/csci1950-l/presentations/REVISED--AFCB%202007%20Course%20Fisher%20and%20Mendel.ppt
Read more about this topic: Phenotypic Trait
Famous quotes containing the words expression, genes and/or organisms:
“Fashion is the most intense expression of the phenomenon of neomania, which has grown ever since the birth of capitalism. Neomania assumes that purchasing the new is the same as acquiring value.... If the purchase of a new garment coincides with the wearing out of an old one, then obviously there is no fashion. If a garment is worn beyond the moment of its natural replacement, there is pauperization. Fashion flourishes on surplus, when someone buys more than he or she needs.”
—Stephen Bayley (b. 1951)
“Whether you want it or not,
your genes have a political past,
your skin a political tone.
your eyes a political color.
...
you walk with political steps
on political ground.”
—Wislawa Szymborska (b. 1923)
“The white man regards the universe as a gigantic machine hurtling through time and space to its final destruction: individuals in it are but tiny organisms with private lives that lead to private deaths: personal power, success and fame are the absolute measures of values, the things to live for. This outlook on life divides the universe into a host of individual little entities which cannot help being in constant conflict thereby hastening the approach of the hour of their final destruction.”
—Policy statement, 1944, of the Youth League of the African National Congress. pt. 2, ch. 4, Fatima Meer, Higher than Hope (1988)