Practice question

Seymour Benzer studied intragenic recombination within rII locus of bacteriophage T4, demonstrating gene is divisible linear array rather than indivisible bead. Using overlapping deletions of rIIA and rIIB cistrons, he crossed thousands of mutants, scoring wild-type recombinants on restrictive K12(lambda) host unable to support rII mutant growth. Recombination frequency between adjacent sites measured subgenic distances, building fine-structure map with resolution down to single base pair. Work introduced terms cistron, muton, recon and proved collinearity of recombination map and coding sequence.