Whole leaf question

I received an extract Pilsner kit for Christmas. The recipe calls to add the whole leaf hops (in a bag) at the last minute of the boil. My question is, what does this do? Should I leave them in the wort during fermentation? Please excuse my ignorance, this my second batch.

 

This is a flavoring addition. Leave them in till you transfer your wort to you fermenter.

 

At one minute,it's an aroma addition. I think 2-5 minutes is better. At flame out,cover it & let it steep for at least a few minutes before chilling down to pitch temp. Remove them before going into the FV. You can squeeze out the bag to get that good juice into the FV as well.

 

Thanks guys.