Multiple ChoiceWhich of the following conditions will result in the fastest transport through the xylem in a tree, assuming adequate water supply in the roots?
Open QuestionWhich 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
Open QuestionWhich 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
Open QuestionWhat 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
Open QuestionMovement 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.
Open QuestionPhotosynthesis 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.