PLANTS
TRANSPORT IN PLANTS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
active loading of water molecules into xylem vessels by endordermis cells
|
|
|
active loading of salts into xylem vessels by endodermis cells
|
|
|
xylem vessels using energy to actively load water upwards
|
|
|
movement of water molecules upwards in xylem vessels through osmosis
|
Detailed explanation-1: -Root pressure is caused by active distribution of mineral nutrient ions into the root xylem. Without transpiration to carry the ions up the stem, they accumulate in the root xylem and lower the water potential. Water then diffuses from the soil into the root xylem due to osmosis.
Detailed explanation-2: -root pressure, in plants, force that helps to drive fluids upward into the water-conducting vessels (xylem). It is primarily generated by osmotic pressure in the cells of the roots and can be demonstrated by exudation of fluid when the stem is cut off just aboveground.
Detailed explanation-3: -As transpiration occurs, it deepens the meniscus of water in the leaf, creating negative pressure (also called tension or suction). The tension created by transpiration “pulls” water in the plant xylem, drawing the water upward in much the same way that you draw water upward when you suck on a straw.
Detailed explanation-4: -In plants, nutrients are absorbed through the active and passive transports. The endodermal cells of the roots containing suberin which allow only selected minerals to pass through them. The transport proteins present in the membranes of these cells act as check points for the various solutes reaching the xylem.
Detailed explanation-5: -Due to active absorption of minerals, high osmotic potential is created. To reduce osmotic potential, water is absorbed, and hence, water potential is increased inside the xylem. Increased water potential also increases pressure in the xylem and this positive pressure is known as root pressure.