If you would like to go into the classroom today and open your notebook in class, the topic might be a little different than when you were in school.
Science is a collection of knowledge that is constantly growing and changing. New discoveries or research often lead to changes in old theories and sometimes even invalidate them. This means that some of the "facts" you learned in school are not necessarily true.
For example, dinosaurs probably don't look the way your textbook depicts them. The origin of Homo sapiens is not as pure as the timeline you may have learned. And many of the nutrition and exercise guidelines in your health classes are debuted.
Here are some scientific facts you may have learned in school that are no longer true.