Question

reading a data table: examine the date found in table 1 and answer questions #1-4.
table 1: growth of eight plants in a three week period

	amount of light per day	amount of water per day	height week 1 in cm	height week 2 in cm	height week 3 in cm
plant 2	0 hours	1 cup	0 cm	0 cm	0 cm
plant 3	4 hours	¼ cup	1 cm	3 cm	6 cm
plant 4	4 hours	1 cup	0.5 cm	1 cm	1.5 cm
plant 5	8 hours	¼ cup	1.5 cm	4 cm	8 cm
plant 6	8 hours	1 cup	1 cm	3 cm	6 cm
plant 7	16 hours	¼ cup	1 cm	2 cm	3 cm
plant 8	16 hours	1 cup	1.5 cm	5 cm	10 cm

1. in this plant growth experiment, what were the two variables tested?
2. what conclusions can be drawn in regards to the amount of light a plant received and how tall the plant grew?
3. what conclusions can be drawn in regards to the amount of water given to a plant and how tall the plant grew?
4. describe which plant or plants did the best and then develop a hypothesis on plant growth based on the data you collected. (get out your scientific method notes!! remember, this should be an \if…then…\ statement)

Explanation:

1. The tested variables are the factors intentionally changed in the experiment, which are listed as separate columns in the table.
2. Compare plant height growth across groups with increasing light hours (holding water constant) to identify trends.
3. Compare plant height growth across groups with different water amounts (holding light hours constant) to identify trends.
4. Identify the plant with the maximum final height, then form an "If...then..." hypothesis linking the optimal conditions to growth.

Answer:

1. The two variables tested are amount of light per day and amount of water per day.
2. For plants given the same amount of water, increased daily light exposure leads to greater plant height growth over the three-week period. Plants with 16 hours of light grew more than those with 8, 4, or 0 hours of light.
3. For plants given the same amount of daily light, receiving 1 cup of water per day leads to greater height growth than receiving ¼ cup of water per day.
4. Plant 8 did the best, reaching 10 cm by Week 3. Hypothesis: If a plant receives 16 hours of light and 1 cup of water per day, then it will grow taller over three weeks than plants receiving less light or less water.