Ch 17: Viruses Flashcards
Capsid proteins and nucleic acid molecules are formed into virus particles by ________.
spontaneous self-assembly
The worst influenza epidemic of the last and current centuries began in what year?
1918
Which of the following is not characteristic of the lysogenic cycle?
Death of the host cell
Which researcher is responsible for the leading model of how prions act as transmissible pathogens?
Stanley Prusiner
A virus has a base ratio of (A+G)/(U+C) = 1. What type of virus is this?
A double-stranded RNA virus
What is a reason that the H5N1 avian flu has not yet become a major human epidemic?
It is not transmitted directly from human to human.
A temperate phage is a phage that is capable of __________.
replicating by both the lytic cycle and the lysogenic cycle
Bacteria defend themselves against viral infection with __________.
restriction enzymes that chop up foreign DNA
A pandemic differs from an epidemic in what way?
A pandemic is a global epidemic.
The reverse transcriptase carried by retroviruses uses what?
viral RNA as a template for DNA synthesis
Which of the following typically contributes to the emergence of human viral diseases?
All of the listed responses are correct.
The “H” designation in influenza strains, such as H1N1 or H5N1, refers to the virus’s type of __________.
hemagglutinin
The largest known viral genomes contain approximately how many genes
A couple thousand
Drugs that are effective in treating viral infections interfere with _____?
the synthesis of viral nucleic acid
The spacer DNA sequences between the repetitive DNA sequences of prokaryote CRISPRs are __________.
bacteriophage DNA
