Question 136·Easy·Command of Evidence
Ecologist Jae Kim tested whether planting flowering cover crops between rows of apple trees would attract beneficial insects. In a one-acre test plot with cover crops, Kim observed a 20% increase in ladybug numbers compared with a neighboring one-acre control plot that lacked cover crops. Based on these results, Kim hypothesizes that expanding the area planted with cover crops will lead to an even greater increase in the orchard's ladybug population.
Which finding, if true, would most directly support Kim’s hypothesis?
For “Which finding would most directly support the hypothesis?” questions, first restate the hypothesis in your own words, identifying the cause (what’s changed) and the effect (what’s measured). Then, scan the choices for the one that (1) changes the same cause in the way the hypothesis describes and (2) reports the predicted effect, ideally stronger or clearer than before. Eliminate answer choices that talk about different variables, side effects (like soil moisture), or results that don’t match the predicted pattern.
Hints
Focus on the hypothesis
Underline the words "expanding" and "greater increase" in the hypothesis. What exactly is Kim predicting will happen when the cover-cropped area changes?
Look for the right variables
Scan the answer choices for one that talks about both (1) changing the area planted with cover crops and (2) the resulting number of ladybugs.
Compare the size of the effect
In the original experiment the increase was . Which option gives a result that shows a larger increase in ladybugs when the cover-cropped area is larger?
Step-by-step Explanation
Restate what the original experiment showed
Kim compared two one-acre plots: one had flowering cover crops between apple tree rows, and the other (the control) did not. In the cover-cropped acre, Kim observed a increase in ladybug numbers compared with the control acre.
Clarify Kim’s hypothesis
Kim now hypothesizes that expanding the area planted with cover crops will lead to an even greater increase in ladybug numbers in the orchard. In other words, if more acres are planted with cover crops, the percent increase in ladybugs should be larger than the original .
Identify what kind of finding would support this
To support this hypothesis, the new finding must:
- Change the area planted with cover crops (for example, more than one acre), and
- Show that this change is followed by a bigger increase in ladybug numbers than before.
Any option that focuses on other variables (like flower species, soil moisture, or pruning) or does not show a greater ladybug increase will not directly support the hypothesis.
Match the answer choice to the hypothesis
One option describes expanding the cover-cropped area to four acres and reports a increase in ladybug numbers compared with the control area. This directly tests Kim’s prediction (more area with cover crops) and shows a larger increase in ladybugs than the original , so “Expanding the cover-cropped area to four acres results in a 35% increase in ladybug numbers compared with the control area.” is the correct answer.