The pressure-flow model of phloem transport states thata. phloem content always flows from the leaves to the root.b. phloem content always flows from the root to the leaves.c. water flow takes sucrose from a source to a sink.d. water pressure creates a flow of water toward the source.e. Both c and d are correct.

Which of the following statements is incorrect? a. Stomata open when K ions move out of guard cells. b. Tracheids but not usually xylem vessel elements are found in both gymnosperms and angiosperms. c. Loss of water is regulated by control of stomatal closure. d. Phloem sieve vessel function is supported by companion cells.

Choose all the correct statements for the graph above:  A.in a mutant plant that makes TWICE the normal number of stomata on the leaf, we would expect the line to shift down (i.e. water potential would become more negative). B. During the period starting with time B and ending with time D, the water potential in the leaf is increasing. C.Transpiration rates are the highest around time B. D.At time A we expect to see the greatest volume of water moving up the xylem to this leaf.

When the stomata are closed, Select one: O a. gas and water exchange increase. O b. water exchange is reduced. O c. gas exchange is reduced. O d. gas and water exchange are reduced. Ch 7 and 8 Written Response signment - Jan 26 Jump to...