Radio Stars. Quasars are the brightest and most distant objects in the known universe. In the early 1960's, quasars were referred to as radio stars because they were discovered to be a strong source of radio waves. In fact, the term quasar comes from the words, quasi-stellar radio source.
The following DNA sequence occurs in the nontemplate strand of a structural gene in bacterium (the promoter sequence is located to the left but is not shown): 5 -GAATGTCAGAACTGCCATGCTTCATATGAATAGACCTCTAG-3 What is the ribonucleotide sequence of mRNA molecule that is transcribed from this piece of DNA?
DNA is the molecule that encodes the genetic instructions enabling a cell to produce the thousands of proteins it typically needs. The linear sequence of the A, T, C, and G bases in what is called coding DNA determines the particular protein that a short segment of DNA, known as a gene, will encode. But in many organisms, there is much more DNA in a cell than is needed to code for all the necessary proteins. This non-coding DNA was often referred to as junk DNA because it seemed unnecessary. But in retrospect, we did not yet understand the function of these seemingly unnecessary DNA sequences. We now know that non-coding DNA can have important functions other than encoding proteins.