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.
Diffen âº Science âº Biology âº Molecular Biology. A gene is a stretch of DNA or RNA that determines a certain trait. Genes mutate and can take two or more alternative forms; an allele is one of these forms of a gene.For example, the gene for eye color has several variations (alleles) such as an allele for blue eye color or an allele for brown eyes.iffen âº Science âº Biology âº Molecular Biology. A gene is a stretch of DNA or RNA that determines a certain trait. Genes mutate and can take two or more alternative forms; an allele is one of these forms of a gene.