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.
We all inherit two copies of every autosomal gene, one copy from our mother and one from our father. Both copies are functional for the majority of these genes; however, in a small subset one copy is turned off in a parent-of-origin dependent manner.These genes are called 'imprinted' because one copy of the gene was epigenetically marked or imprinted in either the egg or the sperm.oth copies are functional for the majority of these genes; however, in a small subset one copy is turned off in a parent-of-origin dependent manner. These genes are called 'imprinted' because one copy of the gene was epigenetically marked or imprinted in either the egg or the sperm.