Malware/Virii/Trojans/Worms

I have Ubuntu set up on my first physical drive, and Windows 7 set up on another partition on that same physical drive. If someone surfs the net to some very questionable websites in UBUNTU, can any infections picked up there be transferred to the Windows 7 partition. If so, is there a way to make a dual boot system where one OS is completely immune from any germs dwelling within the other?
Thank you.

 

Hey Joe, scroll down just a bit to number 2.

http://www.linuxclues.com/articles/21.htm