If you were to file into a classroom and open your notebook for science class today, the subject matter might be a little different than when you were in school.
Science is a body of knowledge that's constantly growing and changing. New discoveries or studies often lead to changes in old theories and sometimes even invalidate them altogether. That means some of the "facts" you learned in school aren't necessarily true anymore.
For example, dinosaurs probably didn't look the way your textbook depicted them them. The origins of Homo sapiens aren't as neat as the timeline you might have learned. And many of the nutrition and exercise guidance from your health classes have been debunked.
Here are some science facts you may have learned in school that aren't true anymore.