Popular “representation” of the human tongue. What tastebuds do we have in region 4 and region 1?

p.s: We all still trust our biology teacher from middle school. Or do we? (Think twice before you post your answer :) )

Cracked by: SV, Bharath, KK, Rogi, Sandesh, Sumanth Patlolla, xeqtor, raklodramA, Siddarth Pai, Riyaz Usman, Debasish, rohanquizzer, Thejas V R, shrey, AmK, jowens, aditthya, krikkrak, krudebox, Logik, Mikey, Abhiram Bharadwaj Diddigi, Dibyo, mankuTimma, S.M.MUNEER ALI, srinivasan, dineshk, Shwetha Maiya and puneet_k