Which of the following best reflects what we know about how the flu virus moves between species?
A) The flu virus in a pig is mutated and replicated in alternate arrangements so that humans who eat the pig products can be infected.
B) A flu virus from a human epidemic or pandemic infects birds; the birds replicate the virus differently and then pass it back to humans.
C) An influenza virus gains new sequences of DNA from another virus, such as a herpesvirus; this enables it to be transmitted to a human host.
D) An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates, the virus is passed to a new species such as a bird, and the virus mutates again and can now be transmitted to humans.
D
You might also like to view...
How do arbuscular mycorrhizae (AM) help plants obtain more nutrients from the soil?
A) Byproducts of AM metabolism serve as primary nutrient sources for the plants. B) The AM increase the total surface area to absorb more nutrients. C) The hyphae develop as specialized nodules that directly produce nutrients for the plant. D) Signaling molecules in the plant are passed to the AM to initiate electron flow, which is in turn used to create ATP.
The majority of digestion in the human body takes place in the ____
a. liver b. mouth c. large intestine d. small intestine e. stomach
Isotopes are unstable and dissipate radioactive energy because they _____________
A. contain additional electrons in the electron orbital B. contain additional protons in the nucleus C. contain additional neutrons in the nucleus D. do not contain enough electrons in the electron orbital E. do not contain enough protons in the nucleus
Which of the following are the primary cellular sites for the recapture of energy from carbohydrates?
a. ribosomes b. lysosomes c. mitochondria d. endoplasmic reticula e. Golgi bodies