What you learned in school
Biology textbooks taught that different areas of the tongue were exclusively responsible for detecting specific tastes: sweet at the tip, bitter at the back, sour on the sides, and salty near the tip sides. Students memorized these "taste zones" from colorful diagrams and performed lab experiments placing taste strips on different tongue areas. This "taste map" was presented as established anatomical fact and became a popular classroom demonstration for decades.
What we know now
Biology classes taught that different areas of the tongue were responsible for detecting different tastes: sweet at the tip, bitter at the back, sour on the sides, and salty on the sides near the tip. Students memorized these zones and drew diagrams. This "taste map" was based on a mistranslation of German research from 1901. In reality, taste buds for all flavors are distributed across the entire tongue, though some areas may be slightly more sensitive to certain tastes. The misconception persisted for nearly a century in textbooks.