Chapter 9, Problem 1RC

Summary Introduction

To determine: The structure and function of bacteria, protists, fungi, and viruses.

Introduction: For a pathogen to maintain a successful host-pathogen relationship, the microbe must be able to find a suitable and nourishing environment inside the host body, which can be either inside the host cells or outside. For a host, an excellent immune system will determine the degree of invasion and the recovery time from the disease.

Explanation of Solution

The bacteria belong to the large class of prokaryotic micro-organisms. They are divided into various categories based on different parameters. These parameters can be shape, cell wall composition, mode of respiration, pathogenicity, and many more. Gram stain demarcates the bacteria into gram-positive and gram-negative bacteria. They can be pathogenic or non-pathogenic and live independently of the host organism. The genetic material of bacteria is DNA and has biomolecules for the replication, transcription, and translation.

Viruses are defined as infectious agents that can survive only by invading the living cells. They reproduce and produce multiple copies of them inside the cells. This causes cell lysis, and after harming the cells, they move to new cells. This cycle keeps on, and this is the reason that viruses are very harmful to living organisms. They are pathogenic, dependent on the host, and do not possess all the essential proteins and molecules for replication and energy derivation. Therefore, they require the host to complete their life cycle.

Protists and fungi are eukaryotic heterotrophic organisms that also depend on organic food and are not entirely dependent on other organisms for food and energy requirements.