Initial studies of the influenza A virus by Walter Fitch and colleagues showed that ________
A) influenza A actually has DNA as its genetic material
B) selection is causing influenza A to become more virulent over time
C) selection by the immune system drives change in hemagglutinin's antigenic sites
D) protein evolution in influenza A is consistent with the neutral theory
E) flu strains from one host cannot exchange genetic material with strains from another
C
You might also like to view...
The inheritance pattern in which the mother provides gene products to the developing egg cells is called
A. X inactivation. B. extranuclear inheritance. C. genomic imprinting. D. linkage. E. maternal inheritance.
All of these are similarities between the male and female system EXCEPT one. Choose the exception
A) Both have erectile tissue that becomes engorged with blood during sexual excitement. B) Both have paired gamete-producing organs. C) Both have a urethra that carries both urine and gametes. D) Both have a pair of tubes that can carry gametes.
In Bacillus anthracis the lethal factor
A. a protease that inhibits blood clotting B. a metalloprotease that lead to cell death C. binds to cells D. is an adenylate cyclase
Which of the following is a potential problem with satisfying Koch’s third postulate in practice?
A. Some disease-causing microorganisms may be found in healthy individuals. B. Some disease-causing microorganisms only cause infection in humans, so no animal models are available. C. Not all disease-causing microorganisms can be isolated and grown in pure culture in the laboratory. D. Some disease-causing microorganisms will not cause disease in all individuals.