PrepTest 156, Section 1, Question 5

Working the answers

• A

  The account doesn't establish that revitalized networks will preserve an essential part of indigenous culture. Their agricultural importance is explained; the added judgment about cultural importance and its preservation is not.

• B

  Heirlooms are presented as a possible solution, not the only conceivable one. Supporting this approach doesn't rule out every alternative way to protect genetic diversity.

• C

  The last paragraph explicitly says many remaining small farmers plant commercial, nonheirloom varieties. They haven't always refused to switch; the switch is part of the problem being described.

• D
  Correct

  Maintaining several varieties allows farmers to take advantage of natural differences in resistance. A disease that harms one variety need not harm every other variety equally. That can make diversity valuable even if one variety offers the greatest immediate yield. The second paragraph supplies the specific benefit, rather than merely declaring variety desirable.

• E

  Indigenous knowledge is valuable, but the text doesn't establish that geneticists must rely on it whenever they develop new varieties. The recommendation to preserve and use this resource is not a claim that every instance of crop development requires it.