var fDesc=new Array(); fDesc[0] = "Build a gene network! The lac operon is a set of genes which are responsible for the metabolism of lactose in some bacterial cells. Predict the effects on lactose metabolism when the various genes and DNA control elements are mutated. Explain the roles of LacI, LacZ, and LacY in lactose regulation."; function tShowHide(id, show) { var s = document.getElementById("desc"); if ((s.innerHTML.length<=212 || show==1) && show!=2) { s.innerHTML = fDesc[id]; if (document.getElementById('m1')) document.getElementById('m1').style.display='none'; if (document.getElementById('m2')) document.getElementById('m2').style.display='none'; if (document.getElementById('more_txt')) document.getElementById('more_txt').style.display='inline'; } else { s.innerHTML = ''; } }