Which structure or compartment is part of the symplast?a. the interior of a vessel elementb. the interior of a sieve tubec. the cell wall of a mesophyll celld. an extracellular air space

Which of the following conditions will result in the fastest transport through the xylem in a tree, assuming adequate water supply in the roots?

What keeps the force of gravity from overcoming transpirational pull?

Which of the following is an adaptation that enhances the uptake of water and minerals by roots?a. mycorrhizaeb. pumping through plasmodesmatac. active uptake by vessel elementsd. rhythmic contractions by cells in the root cortex

Fill in the blanks in this concept map to help you tie together key concepts concerning transport in plants.

What important role does the Casparian strip play in the movement of water through plants?a. forces water to move through the cytoplasm of living endodermal cells as it makes its way from the soil to the xylemb. causes cells to shrink, thereby increasing pressure within cellsc. loads sugars into xylem, thereby causing water to enter the xylem by osmosisd. acts as a filter that prevents salts, heavy metals, and other pollutants from entering root hairs

Movement of phloem sap from a source to a sinka. occurs through the apoplast of sieve-tube elements.b. depends ultimately on the activity of proton pumps.c. depends on tension, or negative pressure potential.d. results mainly from diffusion.

Photosynthesis ceases when leaves wilt, mainly becausea. the chlorophyll in wilting leaves is degraded.b. accumulation of CO2 in the leaf inhibits enzymes.c. stomata close, preventing CO2 from entering the leaf.d. photolysis, the water-splitting step of photosynthesis, cannot occur when there is a water deficiency.

Consider the following statements regarding the transport of phloem sap. Select True or False for each statement.T/F This is a passive process that is driven by the evaporation of water from leaves.T/F Sugars tend to move from sources to sinks.T/F Phloem sap moves through sieve-tube elements under positive pressure.T/F Sieve-tube elements and vessel elements are commonly involved in the transport of phloem sap.