Akela wrote:
Tent caterpillars’ routes between their nests and potential food sources are marked with chemical traces called pheromones that the caterpillars leave behind. Moreover, routes from food sources back to the nest are marked more heavily than are merely exploratory routes that have failed to turn up a food source. Thus, tent caterpillars are apparently among the insect species that engage in communal foraging, which consists in the conveying of information concerning the location of food to other members of the colony, nest, or hive.
Which one of the following, if true, adds the most support to the argument?
(A) A hungry tent caterpillar is more likely to follow heavily marked routes than lightly marked routes.
(B) Tent caterpillars can detect the presence but not the concentration of pheromones.
(C) Sometimes individual tent caterpillars will not return to the nest until a food source is located.
(D) The pheromones left by tent caterpillars are different from the pheromones left by other animals.
(E) The pheromones that tent caterpillars leave behind are detectable by certain other species of caterpillars.
This is Strengthen the Argument type of question.
Let us break down the argument:
Conclusion: Thus, tent caterpillars are apparently among the insect species that engage in communal foraging, which consists in the conveying of information concerning the location of food to other members of the colony, nest, or hive.
Premises:
• Tent caterpillars’ routes between their nests and potential food sources are marked with chemical traces called pheromones that the caterpillars leave behind.
• Moreover, routes from food sources back to the nest are marked more heavily than are merely exploratory routes that have failed to turn up a food source.
Based on the movements of tent caterpillars between their nests and food sources and the fact that they leave chemical traces on these routes, the conclusion that tent caterpillars engage in communal foraging is drawn. We also get the information that the chemical traces are marked more heavily on routes from food sources back to the nest.
Let us now examine the options.
Options D and E are the easiest to eliminate.The given argument doesn’t refer to other animals and does not make any connection between tent caterpillars and other types of caterpillars or other animals. There is a comparison in the argument between the routes from food sources back to the nests and the exploratory routes; the argument states that the former kind of route is more heavily marked than the latter.
Since Option D makes a comparison between tent caterpillars and other animals, it can be eliminated.
Option E states that the routes left behind by tent caterpillars are detectable by other species of caterpillars. However, the conclusion is that tent caterpillars engage in communal foraging, which involves
conveying information to other members of the colony, nest, or hive. There is no mention of conveying the information to other species. So, Option E can also be eliminated.
Option C states that an individual tent caterpillar doesn’t return to the nest until a food source is located. However, this option doesn’t give us any information to support the idea that tent caterpillars engage in communal foraging. This information could just mean that the individual caterpillar searches for food for itself. There is no mention of leaving a trace for other caterpillars to follow.
So, Option C can also be eliminated.Option B weakens the argument. One of the premises is that routes from food sources back to the nest are more heavily marked than exploratory routes. If caterpillars cannot detect the concentration of pheromones, they may not necessarily be following a route that has been marked by one of the caterpillars as a trace route to a food source. So, Option B weakens the argument by showing that caterpillars cannot follow a route because they cannot differentiate between a heavily marked route and an exploratory route.
So, Option B can also be eliminated. Option A supports the idea that tent caterpillars engage in communal foraging by marking routes to food sources more heavily. If a hungry tent caterpillar is more likely to follow a heavily marked route, it is because it most probably expects to find food at the source as the route has been marked by other caterpillars.
Therefore, Option A is the most appropriate option to strengthen the argument.Jayanthi Kumar.
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Crackverbal Prep Team
www.crackverbal.com