No and No,
Android doesn't support linux apps that you can run on a gentoo,ubuntu,fedora,...
And in theory cydia does support any .deb file, however it apps in side won't run.
-- technical mubo jumbo --
although you can copy lets say the firefox binaries and library from your ubuntu to your idroid/ios,...
they won't run. The architecture is different. Your firefox binaries will most likely be i368 (or variants there of like i686) or x86_64. The architecture of the iDevice is different, It's the ARM architecture.
It's more of a hardware issue than a OS one. This is also why you'll never see Windows XP (native) run on an iDevice.