Whether or not the story is true, the symbolism of the thistle (ahem, sorry for the pun) took root and is honored to this day. Other facts about the thistle include that it is a biennial plant, meaning it takes two years to complete its life cycle. It reseeds easily. It's a combination of beauty and ruggedness. It has a spreading, invasive root system, hence its classification as weed.
imprinted gene, a gene whose expression has been affected by genomic imprinting so that only a single allele functions, the other being turned off by epigenetic mechanisms during embryonic development.
Genetic or genomic imprinting is an important process in the mechanism of gene expression. Here genes are expressed based on the parent-of-origin. The phenomena is important for development, but it can also cause serious genetic abnormalities.enetic or genomic imprinting is a mechanism by which gene expression depends on parental origin. The process does not follow the classical Mendelian inheritance rules. A gene comes in two versions (alleles), one from your mum and one from your dad.