Hookworms live inside the intestines of dogs. As the dog eats, the hookworms consume partially digested food. As a result of this nutrient diversion, the dog can become malnourished and weakened. Which BEST describes the relationship between the hookworms and the dog?
a.) a predator-prey relationship
b.) a mutualistic relationship
c.) a producer-consumer relationship
d.) a parasitic relationship

Which of the following is not a characteristic of carnosaurs? a. long narrow skulls b. strong forelimbs c. horn projecting from their skulls d. none of the above

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?

Which of the following typically characterizes a tropical rainforests