PrepTest 43, Section 3, Question 19
Today's farmers plant only a handful of different strains of a given crop. Crops lack the diversity that they had only a few generations ago. Hence, a disease that strikes only a few strains of crops, and that would have had only minor impact on the food supply in the past, would devastate it today.
Today's farmers plant only a handful of different strains of a given crop. Crops lack the diversity that they had only a few generations ago. Hence, a disease that strikes only a few strains of crops, and that would have had only minor impact on the food supply in the past, would devastate it today.
Today's farmers plant only a handful of different strains of a given crop. Crops lack the diversity that they had only a few generations ago. Hence, a disease that strikes only a few strains of crops, and that would have had only minor impact on the food supply in the past, would devastate it today.
Today's farmers plant only a handful of different strains of a given crop. Crops lack the diversity that they had only a few generations ago. Hence, a disease that strikes only a few strains of crops, and that would have had only minor impact on the food supply in the past, would devastate it today.
Which one of the following, if true, would most weaken the argument?
In the past, crop diseases would often devastate food supplies throughout entire regions.
Affected crops can quickly be replaced from seed banks that store many strains of those crops.
Some of the less popular seed strains that were used in the past were more resistant to many diseases than are the strains popular today.
Humans today have more variety in their diets than in the past, but still rely heavily on cereal crops like rice and wheat.
Today's crops are much less vulnerable to damage from insects or encroachment by weeds than were crops of a few generations ago.
Explanations
The author tells us that today's farmers are only planting a handful of strains of a certain crop. Let's say three kinds of corn. Then we're told today's crops lack the diversity they had only a few generations ago. Not a great look for our hypothetical three strains of corn.
Consequently, the author argues, a disease that strikes only a few strains of crops and that wouldn't have affected the food supply in the past would be a major problem today.
This isn't the worst argument of all time, but it's far from proven.
For starters, we don't know that the handful of strains we still plant aren't the most disease-resistant strains that have ever been. That might be the precise reason we've whittled down planting to a handful of strains.
We're asked to weaken the argument, so we need something that makes it less likely that a modern disease would devastate the food supply specifically from planting fewer strains.
Let's take a look.
Nope, but tricky. I'm sure this is true, but the passage discusses diseases that would have had negligible impact in the past. We don't know that these region-devastating diseases would affect today's food supply. And if it did, it would probably strengthen the author's argument that even minor disease can have devastating impact due to lack of biodiversity.
Yes, this is a devastating weakener. If we can quickly replace sick crops from seed banks, then any one disease—no matter how harmful—is unlikely to cause a lasting disruption to our food supply. This is the answer.
Nah, this strengthens the author's argument. If past strains were more disease-resistant, why are we planting the ones we're planting?
No chance. This is a big problem. If we're heavily dependent on specific crops for certain kinds of food, then diseases affecting those crops could seriously disrupt the food supply.
Nope. Irrelevant. We don't care how resistant today's crops are to insects and weeds. We care how well they fend off disease.
0 Comments