A seed or nut of an oak tree is called an acorn in English because that is the name that has come down to us over the past thousand or so years. Both the words oak and acorn words are derived via...
There is a very detailed section in this web page about the acorn production in relation to the age of an oak tree:
http://www.arcytech.org/java/population/facts_oaks.html
But simply, a fully...