Which of the following is an example of herd immunity?
A) Brucellosis is no longer found in farm animals in the United States.
B) If 70% of the population is immunized against polio, the disease will be essentially absent from the population.
C) Federal law requires that all cattle not immune to anthrax be destroyed.
D) All farm animals used for food must be immunized against all the common agents of disease that infect humans.
Answer: B
You might also like to view...
The most successful parasites are the ones that live in harmony with their hosts
Indicate whether this statement is true or false.
Most pH buffers are ____
a. strong acids b. weak acids or weak bases c. weak acids d. strong bases e. strong acids or strong bases
After signal transduction has run its course, receptor molecules are removed from the surface by endocytosis; one
possible fate of the receptor is to be separated from its signaling molecule and returned to the cell surface.
a. True b. False
Which type of lake has the largest amount of nutrients?
A) eutrophic B) oligotrophic C) dystrophic D) lotic