[Campbell Biology P.95] Based on Figure 3.4 and the accompanying text, which statement best... | Practice Question

Based on Figure 3.4 and the accompanying text, which statement best describes how water is transported upwards in tall trees against gravity?

  • A: Evaporation from the leaves creates an upward pull, which is transmitted through the cohesive properties of water molecules and aided by the adhesive properties of water to cell walls.
  • B: Plants actively pump water upwards from the roots using specialized energy-consuming proteins.
  • C: The high specific heat of water allows it to be efficiently pushed up from the roots to the leaves.
  • D: Only surface tension at the leaf surface pulls water molecules from the roots.

Explanation

The text explicitly states: 'Evaporation from leaves pulls water upward from the roots through water-conducting cells. Because of the properties of cohesion and adhesion, the tallest trees can transport water more than 100 m upward.' Figure 3.4 visually reinforces this by showing 'Evaporation from leaves pulls water upward,' 'Cohesion due to hydrogen bonds helps hold together the column of water,' and 'Adhesion of the water to cell walls by hydrogen bonds helps resist the downward pull of gravity.'