QuestenaUn entraînement qui indique quoi revoir ensuite
Question 66

Mark every accurate description of the vessels that make up xylem. Select all that apply.

  1. Each vessel is one living cell that pumps water upwards
  2. The cells that form them are deadBonne réponse
  3. They are hollow, so nothing inside obstructs the flowBonne réponse
  4. The cells are joined end to end into a continuous tubeBonne réponse
  5. Each vessel is kept full of cytoplasm by a living neighbour

Explication

A xylem vessel is a file of cells that die and lose their contents, which leaves an open pipe that water can move along without crossing anything living. The idea that a transport tissue must be alive, or that a living neighbour keeps each vessel topped up with cytoplasm, fails on the same point: contents of any kind would obstruct the water column, and it is the sugar-carrying tissue that stays alive to do its very different job.

Continuer avec ce test

Commencer l’entraînement
Question 66: Mark every accurate description of the vessels that make up… · Plants and Photosynthesis · Questena