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).
Other than these differences, DNA and RNA are the same. Their phosphates, sugars, and bases show the same bonding patterns to form nucleotides and their nucleotides bind to form nucleic acids in the same way. 1  RNA is a single-stranded nucleic acid.2  RNA has a ribose sugar instead of a deoxyribose sugar like DNA. 3  RNA nucleotides have a uracil base instead of thymine.igure %: Common Secondary Structures of RNA. The main difference between the three-dimensional structures of DNA and RNA is that in RNA the three-dimensional structure is single-stranded. The base-pairing that occurs in RNA is all through regions of self-complementarity.