These lesson exercises are for bass guitarist to practice learning and memorizing the location of all of the notes in all twelve keys from the open string notes to the notes near the twelfth fret. These exercises are not necessarily scales as much as they are outlines of notes in keys on all four strings.
I get asked all the time about why some notes are sharp and some are flat. The only way this can be sufficiently explained is to understand “keys” in music. Guitarists generally use the circle of fifths. There are twelve keys in this circle: Seven natural keys, one sharp key and five flat keys.
E Major
The key of E major has three natural notes and four sharp notes: E, F#, G#, A, B, C# and D#.
The outlined note in each exercise is the location of the “key” or root note.
B Major
The key of B major has two natural notes and five sharp notes: B, C#, D#, E, F#, G# and A#.