Pasteur coined the term virus which means poison in Latin. Postulated that rabies is caused

SUBSCRIBE

BIOS 242 Unit 4

• Virus

–Answer Pasteur coined the term virus which means "poison" in Latin. Postulated that rabies is caused by a particle smaller than bacteria in 1884. can infect every type of cell- bacteria, algae, fungi, protozoa, plants, animals.exist in different shapes –Answer helical, polyhedral, complex, icosahedral (bacteriophages), or even bullet shaped.

• Extracellular virus

–Answer Virions –Answer have protein coats (capsids) surrounding nucleic acid

• Intracellular virus

–Answer capsid is removed, and the virus exists as nucleic acid

• Capsid morphology

–Answer Provides protection for viral nucleic acid is a means of attachment to a host's cells.Composed of proteinaceous subunits called capsomeres.

• Rabies virus

–Answer -bullet shaped virus that causes slow, progressive zoonotic disease characterized by fatal encephalitis.-reservoirs of this disease are wild mammals such as canines, skunks, raccoons, badgers, cats, and bats.

• disease spreads to domestic animals and humans through bites, scratches, and inhalation of

droplets. 1 / 3

SUBSCRIBE

• Viral envelope

–Answer -acquired from a host cell during viral replication or release and is the portion of the membrane system of host composed of a phospholipid bilayer and proteins

• viruses with envolope are called enveloped viruses and the ones without the covering

is naked virus.

• Type of Virus

–Answer Bacteriophage –Answer Host –Answer Bacteria

• Type of virus

–Answer plant virus –Answer Host –Answer Plant cells

• Type of virus

–Answer Mycophage –Answer Host –Answer fungal cells

• Type of virus

–Answer Animal virus –Answer Host –Answer Animal cells

• Two noncellular agents, smaller than viruses, are infectious RNA strands called and 2 / 3

SUBSCRIBE

infectious proteins called .–Answer Viroids; prions

• Viruses are

can infect bacteria or eukaryotes acellular infectious agents parasitic microorganisms All of the statements are correct have DNA or RNA as genetic material –Answer All of the statements are correct

• Host cells of viruses include . bacteria

plants and fungi All of the choices are correct.

protozoa and algae humans and other animals –Answer All of the choices are correct

• Genetic material

–Answer

–Answer Viruses are classified by the type of nucleic acid used as the genetic material.

• viral genome may be composed of single-stranded DNA, double-stranded DNA, single-

stranded RNA, or double stranded RNA.

• Positive-sense RNA

–Answer Single-stranded RNA genomes ready for immediate translation into proteins -Norovirus which causes viral gastroenteritis is an example

• Negative-sense RNA
• / 3