proliferate

As a noun taxonomy

is the science or the technique used to make a classification.

As a verb proliferate is

to increase in number or spread rapidly.

As verbs the difference between protract and proliferate

is that protract is to draw out; to extend, especially in duration while proliferate is to increase in number or spread rapidly.

As verbs the difference between proliferate and breed

is that proliferate is to increase in number or spread rapidly while breed is to produce offspring sexually; to bear young.

As a noun breed is

all animals or plants of the same species or subspecies.