Chapter 17, Problem 11TYK

Summary Introduction

To explain:

The reason for the existence of bacterial cells that can grow on a media without requiring threonine, leucine, or biotin and yet requiring methionine.

Introduction:

Lederberg and Tatum experimentally proved that a transformation occurs in the bacterial genome. They did so by placing bacterial cells that require different nutrients to survive on minimal media (media lacking essential nutrients). Some of the colonies from these mixtures, when placed on minimal media, were able to grow without any addition of nutrients. By this experiment, they concluded that genetic recombination had taken place that created new gene combinations capable of synthesizing all nutrients.