Chapter 18, Problem 38A

Summary Introduction

To determine:

Among binary fission, nitrogen fixation and conjugate.

Introduction:

Pathogens are the organisms that are able to infect a host organism and cause disease. The bacteria and the viruses are such pathogens. The flu is a condition caused by infection of viruses in the respiratory tract.

Explanation of Solution

The Asian flu (H2N2) occurred in the year of 1957 and the Hong Kong flu (H3N2) occurred in the year 1968. Both the epidemics were caused by the influenza virus. The Asian flu epidemic was controlled by the vaccine that increased the immunity of the person. So, some of the people who were vaccinated did not get the Hong Kong flu, and by the time the Hong Kong flue emerged, more people were vaccinated that reduced the risk of disease.