The sympathetic nervous systemâs fight-or-flight response is your built-in mechanism for safely escaping a life-threatening emergency, such as a lion lurking behind a bush.
The basic building block of DNA is called a NUCLEOTIDE. A nucleotide is made up of one sugar molecule, one phosphate molecule and one of the four bases. Here is the structural formula for the four nucleotides of DNA. Note that the purine bases (adenine and guanine) have a double ring structure while the pyrimidine bases (thymine and cytosine) have only a single ring.
The backbone of DNA is made up of deoxyribose, a sugar, and are linked together by phosphodiester bonds. RNA is similar but the sugar is called ribose.omponents that form the backbone of DNA and RNA are the same: repeating units of a sugar and a phosphate. In case of DNA, sugar is deoxyribose and in case of RNA the sugar is â¦ ribose. Both of these molecules are very important in the filed of genetics. 2 people found this useful.