A once harmless bacterial species within a bird becomes a pathogen. Which of the following mechanisms could be responsible for this change? A mutation within the bird's genetic material caused the bacteria to become pathogenic.
Horizontal gene transfer between bacterial species within the bird.
Vertical transfer between the bird's cells and the bacteria.
None of these choices.

Which of the following is true? a. under the current unemployment insurance system, benefits replace about 90 percent of the typical worker's prior pretax earnings. b. high benefit payments to unemployed workers will tend to increase the rate of unemployment. c. if a system of personal savings accounts replaced the current unemployment benefit system, the unemployment rate would fall to zero. d. the rate of unemployment in the large european economies has been persistently lower than that of the united states due to their more generous unemployment benefits.