Taylor conducted the experiments to prove semi-conservative mode of chromosome replication on
(1) Vinca rosea
(2) Vicia faba
(3) Drosophila melanogaster
(4) E. coli
(2) The use of radioactive thymidine to detect the semiconservative mode of replication of newly sysnthesised DNA in the chromosomes was performed on Vicia faba by Taylor and colleagues in 1958. This experiment proved that the DNA in chromosomes replicates semiconservatively. Hence the Option (2) is correct.