Plant Evolution

Answer choices

1. A

   Too Strong: proportional15% picked this

   The diversity of secondary substances that develop in a plant population is proportional to the number of insects with which that plant population

   Proportionality is a very strong idea (the more x, the more y). The author never directly connected number of insects interacted with throughout evolutionary history to diversity of secondary substances It's plausible that being exposed to more insects would lead to the evolution of more secondary substances, but we can't support the mathematical precision of saying those two things are proportional.

   15%
2. B

   Somewhat Contradicted Too Strong: few12% picked this

   Although few species of plants have benefited from evolutionary interaction with insects, many species of insects use plants without either harming the plants or

   The plants that interact with pollinating insects seem to benefit from that interaction. In the 2nd paragraph: Some secondary substances are favored by natural selection because they attract pollinating insects. We might have to use our outside knowledge to know that plants benefit from being pollinated (that's how their seed is spread to other plants). If pollinators disappear, tons of important plants follow, because the pollinators play a crucial / beneficial role. But we can also use the context that if these secondary substances are favored by natural selection (which only favors something if it increases the organism's surviving and reproducing), then the pollinating must be a benefit to the organism's surviving and reproducing. No matter what, we have no way to support the quantified claim that few plants benefit from insects. The part about pollinators is a case where plants do benefit. We have no idea what proportion of plants that comprises.

   12%
3. C

   Unknown Comparison: # of families8% picked this

   Throughout the process of evolutionary change, the number of plant species within each family has generally increased while the number of

   There's no line reference to support that the number of plant families has decreased. The only mention of plant families was telling us that often plants will have a secondary substance that shows up (at least in a related form) within several other species in the same plant family.

   8%
4. D

   Correct48% picked this

   No particular secondary substance has appeared in plants in direct response to insects, though in many instances insects have influenced which particular secondary substances

   Why this is right

   Whoa, red flag alert with the strong language: no particular secondary substance has ever been in direct response to insects? Didn't the beginning of the 2nd paragraph say that insects are responsible for the secondary substances? Let's check the text and research our qualms. Insects appear to have played a major role in many plants' having the secondary substances they have today. Such substances undoubtedly first appeared, and new ones continue to appear, as the result of genetic mutations in individual plants. So there is strong language there that's generalizing about all secondary substances. They all first appear as the result of genetic mutation. Insects play a role in determining which of these mutations carries enough survival advantage that it gets naturally selected for and becomes a trait of the species. These first two sentences of the 2nd paragraph give us the support we need for each half of this answer choice (although in criss-crossed order).

   Skill tested: Author Opinion · how this choice captures the passage's function is the move to repeat next time.

   48%
5. E

   Too Strong: none18% picked this

   While many species of insects have evolved ways of circumventing plants' chemical defenses, none has done this through outright

   Again we have some strong language to research. Does it say in the 3rd paragraph that none of the insects have developed outright immunity? They may evolve a way to detoxify a harmful substance, to store it in their bodies out of harm's way, or to avoid its effects in some other manner. That last phrase "or avoid its effects in some other manner" leaves open the door that some insects have evolved outright immunity. De-toxifying or storing it somewhere safe is not immunity. You're either removing the poison or keeping the poison from entering your bloodstream. Immunity would mean that the poison enters your bloodstream, but it doesn't meaningfully affect you. So immunity isn't mentioned, but immunity isn't categorically ruled out, the way this answer is saying.

   18%