Mohanadas obtained a BSc degree from the University of Sri Lanka.
He later received a Phd degree from the University of Adelaide in 1978 after producing a thesis titled Effects of atrizine on the assimilation of inorganic nitrogen compounds in plants and microorganisms.
He served as dean of the Faculty of Agriculture between October 1992 to March 1994.
[2] He served as vice-chancellor of the university between April 2003 and March 2006.
[5] Mohanadas is a member of the University Grants Commission.