trasnport in plants

Question 1

suggest why although photosynthesis is still occurring why plants stop growing when soil water potential falls

Answer 1

-growth involves protein synthesis
-protein synthesis, so no enzymes so no cell wall synthesis stops so no growth

Question 2

most of the water uptake occurs just behind the tip

Answer 2

-Prescence of root hairs creates largest area permeable to water

Question 3

explain how water passes through the endodermis and enters the xylem

Answer 3

-blocks apoplast only symplast pathway
-ions are moved by active transport into xylem
-this lowers water potential water enters by osmosis

Question 4

describe how a high pressure is produced in the leaves

Answer 4

-water potential becomes lower
-water enters by osmosis
-increase in volume of water
-increasing pressure

Question 5

when conducting experiment why is it important that the scientist ensured that the rate of photosynthesis remained constant

Answer 5

-rate of photosynthesis related to sucrose production
-rate of translocation higher than when sucrose concentration is higher

Question 6

apoplast pathway

Answer 6

when water passes from the xylem to the cell wall

Question 7

describe how water in the mesophyll cells passes out of the leaf

Answer 7

-along the cell walls
-through spaces and out through stomata by diffusion.
-from a high water potential down to a low water potential in the leaves

Question 8

lignin is present xylem cell walls

Answer 8

supports and provides structural strength