1.(Z)Maize contains the vitamin niacin, but not in a form the body can absorb. Pellagra is a disease that results from niacin deficiency. When maize was introduced into southern Europe from the Americas in the eighteenth century, it quickly became a dietary staple, and many Europeans who came to subsist primarily on maize developed pellagra. Pellagra was virtually unknown at that time in the Americas, however, even among people who subsisted primarily on maize.
Which of the following, if true, most helps to explain the contrasting incidence of pellagra described above?
A. Once introduced into southern Europe, maize became popular with landowners because of its high yields relative to other cereal crops.
B. Maize grown in the Americas contained more niacin than maize grown in Europe did.
C. Traditional ways of preparing maize in the Americas convert maize’s niacin into a nutritionally useful form.
D. In southern Europe many of the people who consumed maize also ate niacin-rich foods.
E. Before the discovery of pellagra’s link with niacin, it was widely believed that the disease was an infection that could be transmitted from person to person.
2.(Z)Wolves generally avoid human settlements. For this reason, domestic sheep, though essentially easy prey for wolves, are not usually attacked by them. In Hylantia prior to 1910, farmers nevertheless lost considerable numbers of sheep to wolves each year. Attributing this to the large number for wolves, in 1910 the government began offering rewards to hunters for killing wolves. From 1910 to 1915, large numbers of wolves were killed. Yet wolf attacks on sheep increased significantly.
Which of the following, if true, most helps to explain the increase in wolf attacks on sheep?
A. Populations of deer and other wild animals that wolves typically prey on increased significantly in numbers from 1910 to 1915.
B. Prior to 1910, there were no legal restrictions in Hylantia on the hunting of wolves.
C. After 1910 hunters shot and wounded a substantial number of wolves, thereby greatly diminishing these wolves’ ability to prey on wild animals.
D. Domestic sheep are significantly less able than most wild animals to defend themselves against wolf attacks.
E. The systematic hunting of wolves encouraged by the program drove many wolves in Hylantia to migrate to remote mountain areas uninhabited by humans.
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