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AP® Environmental Science

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Clover Experiment Groups

APES-WGLGOY

An experiment was conducted to determine the effects of fertilizer and bacteria on the growth of clover plants. The experiment consisted of 4 groups. All groups received the following treatments:

  • 1 pint of sand
  • 5 clover seeds
  • Equal amounts of water and sunlight

Each group then received various other treatments listed below:

  • Group A: 1 pint of fertilized soil
  • Group B: 1 pint of fertilized soil, rhizobium bacteria
  • Group C: 1 pint of unfertilized soil
  • Group D: 1 pint of unfertilized soil, rhizobium bacteria

The following data were collected (median height of plants measured in centimeters):

Time after planting Group A Group B Group C Group D
1 week 0.9 1.8 0.0 1.0
2 weeks 1.2 2.9 0.2 1.4
3 weeks 1.3 3.7 0.4 1.8
4 weeks 1.5 4.2 0.7 2.1

Which set of groups should be compared against each other to determine the effect of the bacteria on clover height?

A

A & B v. C & D

B

A & D v. B & C

C

A & C v. B & D

D

All groups should be compared to each other.

E

No groups can be compared to determine the effect of bacteria on growth.