PSI. Pounds per square inch: a unit for measuring pressure. One PSI equals the pressure resulting from a force of one pound force acting over an area of one square inch. See pound.
  The four bases that make up RNA are:   * Adenine (A)  * Cytosine (C)  * Guanine (G)  * Uracil (U).denine and guanine are complementary, as are thymine and cytosine. RNA is practically the same, â¦ except that thymine is replaced with uracil (U) - meaning that when RNA replicates DNA, any thymine needed is replaced with uracil. Uracil is still compatible with cytosine, though.
DNA is made up of a base (adenine, thymine, cytosine and guanine), a phosphate and a deoxyribose Sugar. The phosphate and the sugar form the backbone whi â¦ le the bases form the links in between. 1 person found this useful.