Zigya Logo

Chapter Chosen

Transport in Plants

Book Chosen

Biology

Subject Chosen

Biology

Book Store

Download books and chapters from book store.
Currently only available for.
CBSE Gujarat Board Haryana Board

Previous Year Papers

Download the PDF Question Papers Free for off line practice and view the Solutions online.
Currently only available for.
Class 10 Class 12
Explain pressure flow hypothesis of translocation of sugars in plants.

The pressure flow hypothesis states that food is prepared in the plant leaves in the form of glucose. For translocation to the other parts the glucose is converted to sucrose a disaccharide. The sucrose is moved into the companion cells and then into the living sieve tube cells by active transport. This process is called loading and creates a hypertonic condition in the phloem. Water from the adjacent xylem moves into the phloem by osmosis. Increasing osmotic pressure results in the movement of phloem sap to areas of lower pressure. To reduce the osmotic pressure at the sink the sucrose is moved out of the phloem by active transport. The sucrose is converted to energy, starch or cellulose. The removal of the sugars lowers the osmotic pressure resulting in the movement of water out of the phloem. 

 

401 Views

Who introduced the apoplast—symplast concept ?

E. Munch (1930).
630 Views

Why the cortex produces no resistance to movement of water ?

The cortical cells are loosely packed and produce no resistance to movement of water via cell walls or apoplast.
598 Views

What is transmembrane pathway ?

The movement of water through cell membranes is called trans membrane pathway.
1112 Views

Why the water is forced to move through cell membrane beyond endodermis ?

Water is forced to move through cell membranes beyond endodermis because of the suberin (waxy substance) present on radial walls of endodermal cells blocks water and solute movement through cell walls of endodermis. 
923 Views

Give the term for the ability to resist a pulling force.

Tensile strength
731 Views