Chapter 18.2, Problem 3MI

Summary Introduction

To fill:

The correct terms in the given blanks to complete the sentence.

Introduction:

A virus is a little assortment of hereditary or genetic code, either DNA or RNA, encircled by a protein coat. A virus can't duplicate alone.

Answer to Problem 3MI

The correct term is given in the table:

S. No.	Term
1.	Capsid
2.	Lysogenic cycle
3.	Lytic cycle
4.	Prion
5.	Retrovirus
6.	Virus

Explanation of Solution

A virus is genetic material within a protein coat, but it has no organelles or other characteristics of life. The genetic material lies inside its capsid, or outer layer of protein. In the lytic cycle, viral genes instruct the host cell to make many copies of the viral RNA or DNA. Some viruses replicate in a lysogenic cycle, in which the viral DNA integrates into a host chromosome and lies dormant for some time. A retrovirus, such as the HIV virus, contains RNA instead of DNA. Mutation in the genes of a normal protein called a prion is responsible for disease such as "mad cow."