Resin is a plant secretion that hardens when exposed to air; fossilize

The Simple Story

Resin (or amber, in fossilized form) is a particular plant substance that isn’t understood very well. People have confused it with gems, gum, and sap, but it is different from these other substances. Some scientists have hypothesized that the purpose of resin may be to attract or repel insects. It could, for example, repel insects that want to eat the plant. These ideas have led to the development of chemical ecology, the study of how plants use chemicals to interact with other organisms, including as defense mechanisms against attack.

Sample Passage Map

Here is one way to map this passage. (Note: abbreviate as desired!)

P1 Fossil R = amber

≠ gem

≠ gum, sap

R diff b/c function not known

P2 50s: R repel/attract bugs?

plant/bug interdep à chem eco

Step 1: Identify the Question

This is an unusual question stem. It asks for an example of something that would be most likely to fit something described in the passage. Since you will have to extrapolate from the passage information, this is an Inference question.

Step 2: Find the Support

Chemical ecology is mentioned in the second half of the second paragraph.

“Later researchers suggested that resin mediates the complex interdependence, or “coevolution,” of plants and insects over time. Such ideas led to the development of the specialized discipline of chemical ecology, which is concerned with the role of plant chemicals in interactions with other organisms and with the evolution and ecology of plant antiherbivore chemistry (plants’ chemical defenses against attack by herbivores such as insects).”

Step 3: Predict an Answer

The resin hypothesis is used as an example of the “coevolution” of plants and insects over time. That idea in turn led to the development of chemical ecology, the study of how plants use chemicals to interact with other organisms. An appropriate topic, then, will have to do with some kind of relatively complex interaction between plants and insects (or other organisms), and that interaction will have some kind of chemical component.

Step 4: Eliminate and Find a Match

(A) This choice does describe a complex interaction between insects and plants but it does not include a chemical component to that interaction.

(B) This choice describes a relatively simple relationship between insects and plants; it does not include a chemical component of that relationship.

(C) This choice describes a relatively simple relationship between insects and plants; it does not include a chemical component of that relationship.

(D) This choice does describe a chemical issue (herbicides) with respect to plants but it does not include anything about insects or other organisms.

(E) CORRECT. This choice does describe a complex interaction between insects and plants: First the insect makes a change in feeding behavior (develop a tolerance), and later the plant species has some resultant changes. The chemical component is satisfied by the fact that the plant had previously been toxic to the insects.