Viruses are considered nonliving because…

A. they cannot reproduce by themselves
B. they are not made up of cells
C. they cannot carry out metabolism by themselves
D. All of the above

The study of viruses is a part of biology because…

A. they belong to the kingdom Eubacteria
B. they are about to become extinct
C. they are living organisms
D. the are active in living cells

Biologist now know that viruses…

A. are the smallest organisms
B. consist of a protein surrounded by a nucleic acid coat
C. contain RNA or DNA in a protein or lipid-protein coat
D. all form the same crystalline shape

The capsid of a virus is the…

A. protective outer coat
B. cell membrane
C. nucleus
D. cell wall and membrane complex

Viruses are classified according to…

A. whether they contain RNA or DNA
B. the shape of their genome
C. whether they have a membrane envelope
D. All of the above

All viruses have…

A. cytoplasm
B. ribosomes
C. mitochondria
D. None of the above

Tobacco mosaic virus…

A. is able to be crystallized
B. causes disease in tobacco plants
C. is smaller than a bacterium
D. All of the above

Scientists first began to study viruses because they…

A. were seen through a microscope
B. could not be seen but caused disease
C. formed crystals
D. were made of cells

Viruses that use reverse transcriptase to cause their host cells to transcribe DNA from an RNA template are called…

A. bacteriophages
B. antibodies
C. retroviruses
D. capsoviruses

Which of the following contains only RNA?

A. a prion
B. a virus
C. a viroid
D. All of the above

Unlike viruses, prions…

A. are capable of reproducing outside of a host cell
B. are composed only of protein
C. can cause brain infections
D. can be treated with antibiotics

A typical virus consists of…
A. a protein coat and a cytoplasm core
B. a carbohydrate coat and a nucleic acid core
C. a protein coat and a nucleic acid core
D. a polysaccharide coat and a nucleic acid core

Viruses…

A. are cellular organisms
B. reproduce only in living cells
C. have nuclei and organelles
D. are surrounded by a polysaccharide coat

Animal viruses often infect only specific host cells because…

A. the virus must have the DNA as the host cell
B. the host cell must have specific receptors for proteins on the virus surface
C. viruses have receptors for host cell glycoproteins
D. the enzymes of the virus can attach only to specific host cells

Antibiotics are ineffective against viral infections because…

A. host cells protect the viruses
B. viruses have enzymes that inactivate the antibiotics
C. antibiotics interfere with cellular processes that viruses do not preform
D. viral protein coats block the antibiotics from entering the virus

Which of the following is NOT a viral disease of humans?

A. hepatitis
B. SARS
C. shingles
D. All of the above are viral diseases of humans

Which of the following is NOT linked to cancer?

A. Ebola virus
B. human papillomavirus
C. hepatitis B virus
D. Epstein-Barr virus

Which of the following human activities is most closely associated with the emergence of viruses not previously seen in humans?

A. absence of vaccination program
B. crowded living conditions
C. clearing of forests for housing
D. eating uncooked meat

Most scientist think that early viruses originated from…
A. other viruses
B. existing cell parts
C. animals
D. spontaneous generation

HIV causes AIDS by…

A. converting a proto-oncogene to an oncogene
B. damaging a person’s blood vessels
C. destroying the covering of a person’s nerves
D. gradually destroying a person’s immune system

Which of following is NOT a vector of viral diseases?

A. mosquitoes
B. ticks
C. prions
D. humans

Which of the following has been the most successful at fighting viral diseases?

A. vaccination
B. vector control
C. drug therapy
D. Both a and b

Most scientist believe that viruses first appeared on Earth _____ living cells appeared.

A. after
B. a very long time before
C. at the exact time when
D. immediately before