What are the notes on a bass ukulele?

The strings on a bass ukulele are usually tuned, from the thickest to the thinnest, E A D G.  This tuning is the same as several instruments, including a bass guitar, a double-bass, and the bass notes on a standard guitar.
As with any 'chromatic' instrument, any pitch can be played depending on how the strings are tuned and the position of the fingers on the fretboard.
Buzzards Field sell a kit which allows a small classical guitar to become a short scale bass ukulele and accept bass ukulele strings.