Water flows up a plant's stem against the force of gravity.

In which of the following ways could the movement of water up a plant be modeled?
A.
Blow through a clear straw in a glass of water. Observe the level of water inside the straw.
B.
Place the tip of a sponge in water dyed with food coloring. Watch how the water moves up the sponge.
C.
Place a clear pipe in a small tub of water. Shake the tub back and forth. Watch how the water moves around the pipe.
D.
Pour a glass of water on top of a towel that is spread out on a table.

1 answer

The movement of water up a plant's stem could be best modeled by option B: Place the tip of a sponge in water dyed with food coloring. Watch how the water moves up the sponge.

This option closely represents the capillary action and absorption processes found in plants, where water moves through the sponge similarly to how it moves through the plant's xylem vessels. The dyed water provides a visual representation of how water is absorbed and moves upward against gravity, much like it does within the plant.

The other options do not accurately model the upward movement of water in the same way:

  • A (blowing through a straw) demonstrates air pressure rather than water movement against gravity.
  • C (shaking a pipe in water) is more about movement in a contained environment than upward flow.
  • D (pouring water on a towel) illustrates absorption but does not represent the upward movement against gravity as effectively.