1

What organ was once believed to be completely useless before scientists discovered its role in immune function?

2

What celestial body was long taught to be a planet until it was officially reclassified in 2006?

3

What continent was once taught to be the only one without native dinosaur fossils, a claim later disproven?

4

Old maps and textbooks depicted California as what geographical feature until the 18th century?

5

Early 20th-century textbooks claimed ulcers were caused by stress and spicy food. What organism is now known to cause most ulcers?

6

What was once believed to be the cause of malaria before the discovery of mosquito transmission?

7

What extinct bird was once thought to have gone extinct because it was "stupid" and unwilling to move out of harm’s way?

8

What writing system was once considered impossible to decipher until the Rosetta Stone provided a key?

9

Schoolbooks once claimed that camels store water in their humps. What do they actually store?

10

Before 2012, what elementary particle had never been confirmed, leading textbooks to describe it as only theoretical?