Six Plants Beside the Survey Wagon
A class visited a survey wagon where workers make maps of the desert. Beside the wagon, Imani helped investigate young brittlebush plants. Brittlebush is a desert shrub. The class wanted to find out whether different amounts of water could affect plant height, a measurable trait.
First, the class chose six healthy plants of the same kind and age. Each plant was 8 centimeters tall. They used matching pots with equal amounts of the same soil. They placed the pots together under a bright shade canopy, where the plants received similar light and warmth.
Next, students labeled three plants L1, L2, and L3. Each received 15 milliliters of water daily. Plants W1, W2, and W3 each received 60 milliliters daily. A milliliter is a unit for measuring liquid. Rain did not reach the pots. Students kept the watering plans for 14 days. They measured each plant from the soil surface to its highest growing tip. The graph shows their final measurements.
Then the class tried a follow-up for seven more days. L1 received 60 milliliters daily instead of 15. L2 and L3 continued receiving 15 milliliters daily. The class kept their pots, soil, and location the same. L1 grew from 10 to 12 centimeters. L2 stayed 11 centimeters tall, and L3 stayed 10 centimeters tall.