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Question 82

A potometer is set up with a freshly cut leafy shoot. What does the apparatus actually measure?

  1. The mass of vapour leaving the leaves
  2. The rate at which the shoot takes up waterBonne réponse
  3. The volume of sugar moving through the phloem
  4. The number of open pores on the lower surface

Explication

The bubble in the tube moves as the shoot draws water in, so what is read off the scale is uptake, and that reading is then used as an estimate of the water being lost. Vapour leaving the leaves is never collected by the apparatus, and a little of the water taken up stays inside the plant, so treating the reading as a direct measurement of loss claims more than the equipment can show.

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Question 82: A potometer is set up with a freshly cut leafy shoot. What… · Plants and Photosynthesis · Questena