A study question tests what you can conclude from a comparison of groups or conditions. Read how the trials differed, then name each condition and what it showed. If the text reports two results, ask how each changed. A cause shared by both conditions can't explain a difference between them, so look to what changed. Then keep your conclusion narrow, because a result under one set of conditions doesn't prove a rule for every possible case.
Hints
- Hint 1
Read the standard trials and the separate series, and identify what the team changed.
- Hint 2
For each series, pair the release times with the fertilization rates. What conclusion about the team's change accounts for both results?
Step-by-step
Compare the trial conditions
Step 1Identify what changed
The standard pulses began four nights after the full moon. What did the team change that could support the hypothesis the blank asks for? They delayed the start of the nightly pulses by two days, so timing was the tested difference.
- Step 2
Pair each schedule with its results
What happened under each schedule? In the standard trials, releases fell within about an hour of one another, and fertilization rates were high. After the delay, colonies staggered their releases over several hours, and fertilization rates declined. Less closely timed spawning went with lower fertilization, so the hypothesis must explain both changes.
- Step 3
Stay within what the trials show
Why does that difference point to the light schedule? Both conditions used nightly pulses, so the presence of light alone can't explain the gap between their results. The starting day changed, and the delayed schedule was followed by poorer coordination and lower fertilization. The results suggest the pulse schedule may affect both coordination and fertilization, though they don't tell us what happens under schedules the team didn't test.
- Step 4
Match both parts of the hypothesis
The claim about the timing of lunar-like light cues ties both spawning coordination and fertilization to the tested change. Synchronizing coral spawning describes releases lining up, while maximizing fertilization success covers the higher rates seen with closely timed releases. Choice A.