What is the oldest form of biotechnology? selective breeding hybridization cloning recombinant dna

The correct answer is selective breeding.

The selective breeding is a technique, in which the animals or plants of a desired trait is selected an bred, in order to obtain the desired trait in the progeny.

The technique of selective breeding is very ancient, even it was used by Mendel in his pea plant experiment. With the advancement in the techniques of biotechnology, hybridization, cloning, and recombinant DNA technology was developed.

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

the principles and empirical processes of discovery and demonstration considered characteristic of or necessary for scientific investigation, generally involving the observation of phenomena, the formulation of a hypothesis concerning the phenomena, experimentation to test the hypothesis, and development of a conclusion that confirms, rejects, or modifies the hypothesis.