Tag: mineral transport

• Negative hydrostatic pressure develops at the time of water loss, it occurs when the water is lost through transpiration and creates tension in the cell.
• Transpiration is the process in which water is lost through the upper or aerial plant parts in the form of water. 
• Imbibition is the swelling of cells that occurs due to the absorption of water. 
• Positive pressure is the force in the xylem which exudates drops of liquids through the stoma to the outside and also requires hydathodes which help in the process of guttation (exudation of water droplets mostly from the leaves margins). 
  

Food from the leaves is conducted downwards through the phloem in the stem.conduction of water through the xylem occurs generally upwards.

Xylem transports and stores water and water-soluble nutrients in vascular plants. Phloem is responsible for transporting sugars, proteins, and other organic molecules in plants.

Water and salt travel upwards mainly in the xylem and food substances travel up and down in the phloem.

Leaf has epidermis on both of its surfaces. The photosynthetic tissue of a leaf is sandwiched between its upper and lower epidermis and is well supplied by the vascular system. In a leaf, xylem always faces the upper epidermis i.e. the adaxial side while phloem faces both upper as well as lower epidermis.

Active transport is a process that is required to move molecules against a concentration gradient. For plants to take up mineral ions, ions are moved into root hairs, where they are in a higher concentration than in the dilute solutions in the soil. So, the correct answer is "Active Transport".

Translocation of organic nutrients from the region of source or supply to the region of sink or utilisation is mostly in the form of sucrose. Phloem (sieve tubes or sieve cells) is the pathway for this translocation, as found put by stem girdling, sieve tube puncturing, radioautography and chemical analysis of sieve tube sap.

• The cohesion-tension theory is a theory of intermolecular attraction that explains the process of water flow upwards (against the force of gravity) through the xylem of plants. 
• Transpiration pull, utilizing capillary action and the inherent surface tension of water, is the primary mechanism of water movement in plants. 
• Hence, The cohesion transpiration pull theory operates only in Conditions favouring transpiration.
• So, the correct answer is 'Conditions favouring transpiration'.

In vascular plants, water and minerals move through xylem, whereas sugars move through phloem. Ringing experiments prove that sugars move through phloem. If the phloem tissue is removed in a ring or girdle, the sugars cannot be transported to roots from aerial parts and plant dies.