Chapter 18, Problem 28A

Summary Introduction

To describe:

If viruses are living organism.

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 viruses are small and less complex and consists of genetic material and protein covering.

Explanation of Solution

A substance can be considered as living if they have characteristics of the living organism. These characters are listed below:

1. All organisms are made up of cells. Viruses do not have a cell.
2. Living organism can respond to the external stimuli. Viruses cannot respond to external changes if they are not present inside the body of an organism.
3. They grow and divide. Growth and division of the viruses cannot occur own its own they need host cells that can accumulate them and integrate their genome to the host that can be multiplied as host’s genome.
4. They are capable of performing all the metabolic processes necessary for their survival. Viruses do not perform any metabolic process.
5. They require nutrition to survive and obtain it from various sources. Viruses do not acquire nutrients.

As most of the characters of living organism are not present in viruses, they cannot be considered as living.