Chapter 20, Problem 6STP

Summary Introduction

Introduction :

A virus is a parasite not able to reproduce on its own. However, once it contains a susceptible cell, a virus can guide the cell mechanism to produce more viruses. Most viruses are genetically modified with either RNA or DNA. The nucleic acid can be individual-or double-stranded. The whole structure of the infectious virus, called a virion, consists of the nucleic acid and a protein outer shell.

Answer to Problem 6STP

Correct answer :

The correct answer is option (D) types of genetic materials.

Explanation of Solution

Explanation/justification for the correct answer :

Option (D) types of genetic materials. The characterization of viruses is based on the type of nucleic acid they consist. It is the genetic materials that enter inside the host cell to replicate. So, the correct answer is option (D).

Explanation for incorrect answer :

Option (A) capsid protein. The protein capsid of the viruses encloses the genetic materials once the genetic materials enter inside the host cell, the virus detach the protein shell. So, this is an incorrect option.

Option (B) chromosome number. The viruses are very small microorganism to distinguish based on the chromosome number it’s the nucleic acid which shows the difference. So, this is an incorrect answer.

Option (C) host resistance. Host resistance may vary between different types of viruses but it is not the basic characteristics for classification. So, this is an incorrect answer.