Chapter 7, Problem 9CTQ

a.

Summary Introduction

To describe:

The number of bacterial cells that are present 3 hours after introducing 20 bacterial cells to the pasta salad, assuming that the generation time is 20 minutes.

Concept introduction:

Exponential growth involves a growth in the cell population by a factor of 2. These populations contain a high number of cells; therefore they are represented as exponents. When the exponential number and time graph is plotted, the line comes out to be straight, representing exponential growth.

Doubling time is the time taken by a bacterial cell to form two daughter cells, after completing a fission cycle. It is also referred to as generation and is a constant process under favorable conditions. In bacteria, each doubling time leads to a doubling of their population. This process leads to an exponential growth in their population. Each exponent represents a generation in exponential growth.

b.

Summary Introduction

To describe:

The way in which microbial contamination of the salad could have been prevented or reduced.

Concept introduction:

Doubling time is the time taken by a bacterial cell to form two daughter cells, after completing a fission cycle. It is also referred to as generation and is a constant process under favorable conditions. In bacteria, each doubling time leads to a doubling of their population. This process leads to an exponential growth in their population. Each exponent represents a generation in exponential growth.