A finding question with a two-part conclusion tests whether evidence backs up the whole claim. Read the conclusion and split it into its parts, including what happens and what need not cause it. Then predict a finding that shows the change while ruling out the other cause. Check that the finding uses the same groups and measures what the claim says changes. Evidence that shares the topic but leaves one part untested isn't enough.
Hints
- Hint 1
Find the final sentence and ask what is supposed to last longer. Which weekly record would test that part of the claim?
- Hint 2
Compare blossom counts during weeks when each plot is blooming. What would that comparison let you check about the second part of the conclusion?
Step-by-step
Test the effect and the other cause
Step 1Measure how long pollinators use the plots
The conclusion says the mix can prolong the portion of the season when pollinators use rooftop habitats, so we're looking for evidence about time. What should the weekly records show? Weeks with pollinator visits measure how long the plots are used, because more visits across the season could mean busier weeks rather than a longer season.
- Step 2
Separate a longer season from denser displays
What else does the conclusion ask us to show? The effect need not result from mixed-species plots having denser floral displays while in bloom, so a longer visiting season alone won't be enough. The plots have the same area, so more open blossoms would mean a denser display. Compare blossom counts during active-bloom weeks. We'd predict more weeks with visits in mixed plots even when their blossom counts during bloom are about the same as those in monocultures, plots with one species.
- Step 3
Cross out findings that miss a part
Which findings miss a part? The finding with substantially higher blossom counts leaves denser displays as a possible cause, while the same number of weeks fails to extend pollinator use. Plots that had open blossoms over more weeks show longer flowering, but similar total visits don't tell us how many weeks had visits. Longer blooming doesn't prove longer pollinator use.
- Step 4
Test both parts together
In the finding with comparable mean numbers of open blossoms, both plot types have about the same number of flowers open while blooming. Yet mixed plots receive visits over more weeks on average, so the longer visiting season happens without a denser display. Choice D.