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.
Second, while DNA contains deoxyribose, RNA contains ribose (in deoxyribose there is no hydroxyl group attached to the pentose ring in the 2' position). Third, the complementary base to adenine is not thymine, as it is in DNA, but rather uracil, which is an unmethylated form of thymine.Source(s):. RNA is made out of ribose, as opposed to deoxyribose. 2. DNA had adenine, guanine, cytosine, and thymine. In RNA, the thymine is replaced with uracil.