Breeding of strawberries variety "Old Black", which is of uncertain origin. This variety was created by pollination, not direct manipulation of the plant's genes. Molecular breeding is the application of molecular biology tools in a breeding program. Genetic engineering is typically defined as the introduction of non-native genes into an organism. An excellent example of transgenic modification is in the case of cold resistant strawberries. In one particular variety genes from the arctic flounder, a fish that lives in very cold water, were used to give plants resistance to cold. This modification works because of the genetics of the arctic flounder. It lives
What Is and What Should Never Be descending riff [of "What Is and What Should Never Be"] is amazing: It's like a bow is being drawn back, and then it releases. The rhythm of the vocals is almost like a rap. It's insane — one of their most psychedelic songs." This was also one of the first songs recorded by the band for which Robert Plant received writing credit. According to rock journalist Stephen Davis, the author of the Led Zeppelin biography "Hammer of the Gods: The Led Zeppelin Saga", the lyrics for this song reflect a romance Plant had with his wife's younger sister. "What Is