Question

(i) What did Meselson and Stahl observed?
When
(a) They cultured E. coli in a medium containing 15NH4Cl for a few generations and centrifuged the content?
(b) They transfered one such bacterium to the normal medium of NH4Cl and cultured for two generations.
(ii) What did Meselson and Stahl conclude from his experiment? Explain with the help of diagrams.
(iii) Which is the first gentic material? Give reasons in support of your answer.

Answer 1

Measurement of superoxide dismutase, catalase and glutathione peroxidase in cultured cells and tissue. Author information: ... Cells contain a large number of antioxidants to prevent or repair the damage caused by reactive oxygen species, as well as to regulate redox-sensitive signaling pathways.