transpiration stream

Question 1

what is adhesion

Answer 1

attraction between water molecules and the walls of the xylem vessel

Question 2

what is cohesion

Answer 2

attraction between water molecules caused by hydrogen bonds

Question 3

What is the transpiration stream

Answer 3

The movement of water from the soil, to the plant, to the air

Question 4

What is the main force of the transpiration stream

Answer 4

Water potential gradient

Question 5

What mechanisms transports water and minerals

Answer 5

Water- osmosis

Minerals- Active transport

Question 6

what is the casparian strip

Answer 6

Waxy waterproof band of suberin, blocks apoplast pathway forcing water through the simplest pathway
Function- may allow plants to control which minerals reach the xylem

Question 7

why is the endodermis known as a starch sheath

Answer 7

because it contains granules of starch

Question 8

why does the root has a casparian strip which is between the root cortex and medulla and xylem

Answer 8

it blocks the apoplast pathway and ensures water and minerals have to pass through the cytoplasm

prevents backflow of water from medulla and xylem

Question 9

why does the tip of a root actively transport mineral ions into the cytoplasm

Answer 9

makes water potential of cytoplasm more negative for water can osmose in down the water potential gradient

Question 10

what water pathway does water move across a root

Answer 10

down an apoplast pathway- water moving by mass flow down cell walls and between cells

Question 11

what do transport proteins on the plasma membranes do

Answer 11

allow active transport of minerals from root cell cytoplasm to the medulla and xylem- lowering water potential allowing water to enter by osmosis