Self-study
When soil is plowed in the spring, pigweed seeds that have been buried in the soil all winter are churned up to the surface and redeposited just under the surface. ███ █████ ████████ ██ ███ █████ ██ ████████ ██████████ ██████████ █████ ████ ██████ ██████ █████████ ██ ████████ ██████ ███ ██████ ███ █████ ████ ██████ ██ ███ █████ ███ ███ ██████████ █████████ ███████ ████████████ ███████ ███ █████████ █████████ ████████ ██ ████████ ██ █████████ ███ █████ ██ ███ ██████████
Summary
When soil is plowed in the spring, pigweed seeds are churned up and redeposited just under the surface. Brief exposure to sunlight stimulates receptors. When receptors are stimulated, germination is triggered. Prolonged darkness, followed by exposure to sunlight, is necessary for the seeds to germinate.
Strongly Supported Conclusions
Fewer pigweed seeds will germinate when a field is plowed at night versus a field that is plowed during the day.
14.
The statements above, if true, ████ ████████ ███████ █████ ███ ██ ███ █████████ ██████████ █████ █ █████ ████ ████ ██ ██████ ██ ███ ██████ ███ ██ █████ ███████ █████ ████ ████ ██████ ██ ███ ████ ███ ███████
a
Fewer pigweed plants ████ ████ ██ ███ █████ ██ ██ ██ ██████ ████ ██ █████ ████ ██ ██ ██ ██████ ██████ ███ ████
This answer is strongly supported. The last sentence tells us that exposure to sunlight is necessary for seeds to germinate. There is no sunlight at night, therefore the seeds are less likely to grow.
b
Fewer pigweed plants ████ ████ ██ ███ █████ ██ ██ ██ ███ ██████ ██ ███ ████ ██ ██ ██ ██████ ████ ██ ██████
This answer is unsupported. We don’t know from the stimulus what occurs whenever a field is not plowed at all.
c
Fewer pigweed plants ████ ████ ██ ███ █████ ██ ██ ██ ██████ ████ ██████ ███████ ████ ██ ██ ██ ██████ ████ █████ ███████
This answer is unsupported. Before sunrise and after sunset both imply darkness. Exposure to sunlight is necessary for seeds to germinate.
d
The pigweed seeds ████ ███ ███████ ██ ██ ███ ███████ ██ ███ ████ ██████ ███ ███████ ████ ███ █████████ ██████ ████ ███ ███████████ █████ ███ ███████ ██ ███ █████
This answer is unsupported. We don’t know from the stimulus whether the seeds being redeposited is a necessary condition for germination.
e
All of the ███████ █████ ████ ███ ███████ ██ ███ ███████ ██ ███ ████ ██████ ███ █████ ██ ██████ ████ ██████████
This answer is unsupported. The last sentence tells us that prolonged darkness is necessary for seeds to germinate. If the seeds are already on the surface, then they were not exposed to prolonged darkness.