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.
The two main types of nucleic acids are DNA and RNA. Both DNA and RNA are made from nucleotides, each containing a five-carbon sugar backbone, a phosphate group, and a nitrogen base. DNA provides the code for the cell âs activities, while RNA converts that code into proteins to carry out cellular functions.