The tangent plane at the point x=a, y=b is the plane that contains all the tangent vectors (at the point) of curves on the surface that pass through the point (a,b,f(a,b)). Another way to define it is to say that this is the plane through the point (a,b,f(a,b)) which is perpendicular to the NORMAL to the surface at that point. The NORMAL to the surface at a point is just defined as the direction perpendicular to all tangent vectors to the surface at that point. Therefore all we need to do to find the equation of the tangent plane is to find a normal to the surface at that point.
Apart from adenine (A), cytosine (C), guanine (G), thymine (T) and uracil (U), DNA and RNA also contain bases that have been modified after the nucleic acid chain has been formed. In DNA, the most common modified base is 5-methylcytosine (m 5 C). In RNA, there are many modified bases, including those contained in the nucleosides pseudouridine (Ï), dihydrouridine (D), inosine (I), and 7-methylguanosine (m 7 G).
DNA is made up of chains of nucleotides, molecules made up from purine, pentose sugar, and a phosphate group, put onto a sugar and phosphate backbone and wrapped around each other; this is called a double helix. There are four bases in DNA; guanine, cytosine, adenine, and thymine.here are four bases that make up RNA just as DNA has. RNA's four bases consist of adenine, cytosine, guanine, and uracil. RNA is also what a mutagen looks for. If a mutagen takes over RNA it is able to change the DNA and make the cell do what the mutagen wants it to do rather then what it is supposed to do.