A table question with competing models tests whether you can use numbers to tell their predictions apart. Read each model’s claim, then check the title and column headings to see what the table measures. Ask which comparison separates the models, and compare rows that hold other factors steady. Work out the differences needed to test the claim, then check every part of each choice, because one false number can spoil otherwise useful evidence.
Hints
- Hint 1
Read the two model descriptions. Ask what each one says should control flowering time.
- Hint 2
Which rows let you check the role of warming time without changing the 24-hour mean?
- Hint 3
Work out the difference for each pair of rows you use. Track both the days to first flower and the change in the 24-hour mean.
Step-by-step
Compare warming time at the same mean
Step 1Find what separates the models
The first model says flowering depends mainly on the 24-hour mean temperature, regardless of when warming occurs, while the alternative says nighttime temperature has a disproportionately large influence. The models disagree about whether warming time matters. How can we test that? Let’s compare regimes with the same mean but different warming times, because the first model predicts similar flowering times.
- Step 2
Compare flowering at the same mean
Which rows test whether flowering depends on the mean regardless of when warming occurs? The headings show day temperature, night temperature, daily mean, and days to first flower; fewer days means earlier flowering. Day-warmed and night-warmed both average 21°C, but flower in 43 and 35 days. At the same mean, night-warmed plants flower eight days earlier than day-warmed plants, since 43 minus 35 is 8.
- Step 3
Check each mean-temperature increase
The 24-hour mean temperature is 19°C for control, 21°C for either the day-warmed or night-warmed regime, and 23°C for both-warmed. Does adding warming to one period raise the mean by different amounts? Every such step raises the mean by 2°C. The phrases twice as much and the 24-hour mean increases differed each misread this column.
- Step 4
Test what daytime warming adds
Adding day warming to the night-warmed regime completes the comparison: flowering falls from 35 to 34 days. Day warming makes flowering only one day earlier once nights are warm. The choice with eight days sooner and only one additional day gives both differences correctly, so it supports the claim that nighttime temperature has a disproportionately large influence. Choice A.