conjugation in bacteria was discovered by

1. beadles and tatum
2. zinder and lederberg
3. griffith
4. lederberg and tactum

The correct option is 4.
Bacterial conjugation is the transfer of genetic material (plasmid) between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells. Discovered in 1946 by Joshua Lederberg and Edward Tatum, conjugation is a mechanism of horizontal gene transfer as are transformation and transduction although these two other mechanisms do not involve cell-to-cell contact.