Multiple choice 2 ribosomal sub-units remain together with each other because of____________. - high concentration of Mg++ ions low concentration of Mn++ ions high concentration of Ca++ ions low concentration of Mg++ ions Reveal answer Fill a bubble to check yourself A Correct answer Explanation Ribosome is large & complicated cell organelle presents in almost all living cell that serevs as the major site of biological protein synthesis. 2 ribosomal sub-units remain together with each other because of high concentration of Mg++ ions.