Concept explainers
To determine: The reason for no growth of the unmixed bacterial strains in the Lederberg and Tatum experiment.
Introduction: The experiment performed by Lederberg and Tatum was conducted to understand the mechanism of transformation in bacteria. The experiment was later continued by Davis to finally prove that direct contact is pre-requisite for conjugation to occur.
To determine: The significance of the mixed strains on the culture plate.
Introduction: The mixing of the strains met– bio– thr+ pro+ and met+ bio+ thr– pro– did not produce colonies due to lack of the mechanisms to synthesize the required amino acids. However, the mixing of the strains lead to production of new strain, which was capable of growing on the culture media
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