[ 327 ] Life Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • Refer to the following passage to answer the next three questions. A company claims that its new fertilizer, brand X, will make plants, such as tomato plants, grow faster and produce more fruit than a leading brand by another company, brand Y. The directions for each fertilizer indicate that they are used at the same concentration (50 g/kg soil). A scientist uses 150 tomato plant seedlings. He divides the seedlings into three groups of 50 plants. Each seedling is 10–12 cm high at the start of the study and is planted in a pot containing 1 kg of potting soil; the soil is identical for all groups. To one group (control), nothing is added to the soil. To a second group, 50 g of brand Y is added to the soil of each plant. To a third group, 50 g of brand X is added to the soil. All the plants are grouped together in the same greenhouse at a constant temperature of 25°C. The light in the greenhouse is uniformly illuminated and all plants are exposed to a 12- hour on/off cycle. The plants are carefully watered each day with 200 mL of water each. The height of each plant is measured and recorded weekly for 20 weeks. In addition, the amount of tomato fruit produced by each plant is noted at the end of the experiment (week 20). Effect of Fertilizer on Tomato Plant Production Treatment Average number of tomatoes per plant Control 3.5 Brand Y 7.2 Brand X 6.1 Did treating the plants with fertilizers increase the fruit production? Consider the hypothesis. Did the plants treated with brand X produce more fruit than those treated with brand Y?