Chapter 18, Problem 9TYPSS

Summary Introduction

To analyze:

After treatment of cells with mutagen, the number of cells to be screened to have a good chance of finding one mutant.

Introduction:

Scientists Monod and Jacob studied production of β-galactosidase through E. coli to identify key regulated genes in gene regulation. They use mutants to analyze E.coli cells which are deficit in lactose metabolism, whether mutants would lead them with regulation of lactose metabolism. The primary aim was screening of treated cells for mutants with defects in the biochemical process or pathway to study defects in lactose metabolism. The cells in a medium are examined for the mutants that cannot grow on lactose. The medium is treated with a mutagen, after which it is anticipated that the mutation rate must be $1\times {10}^{-4}$ per cell.