Researchers noted that about half of all species of bacteria contain small segments of dna of about 20–50 base pairs derived from plasmids or viruses. the phrase clustered regularly interspaced short palindromic repeats (crispr) describes the organization of these viral dna segments in the bacterial genome. bacteria use crispr to: (select all that apply.) identify viral dna by complementary base pairing with template dna. transcribe rna that combines with a protein that has a dna-cleaving function. copy part of the bacteria genome and incorporate it into a viral genome. transcribe rna that combines with a protein that has a rna-cleaving function. "remember" the first time it was infected with a virus. identify viral dna by complementary base pairing with rna.