Chapter 9: Microbes, Algae, Plants

All organisms have ______.

Viruses

What is a virus?

Infectious particle consisting of genes packed into a protein coat (capsid)

Viruses can infect…

Bacteria, protists, algae, plants, fungi, and animals

Are viruses organisms? Why or why not?

They are not really organisms.

They cannot reproduce or carry out metabolism outside a host cell.

Are viruses considered cells? Why or why not?

Viruses are not cells. They are small infectious particles that consist of a nucleic acid enclosed in a capsid and in some cases a membranous envelope.

Viral genomes consist of either

• Double or single stranded DNA or (DNA viruses)

• Double or single stranded RNA (RNA viruses)

The viral genome is either

Single linear or circular molecule of a nucleic acid

Capsid

Protein shell the encloses the viral genome

To infect an animal most viruses have:

A membranous envelope that binds to receptors on the surface of a host cell