In simple dominance, the dominant trait a. is masked by the recessive trait
b. masks the recessive trait

b. maks the recessive trait

Quick explanation:

The dominant trait masks the reccessive gene, but the person still has the gene, it just won't affect them, it might affect their future generations. For example, the trait for blue eyes is a recessive trait, so in order for you to have blue eyes, both parents will need to have the gene for blue eyes.

not sure if this is what you'r looking for eubacteria and archaebacteria