WATER & MINERAL MOVEMENT

1. WATER & MINERAL MOVEMENT

2. XYLEM

3. TRACHEIDS 1. DEAD 2. TAPER AT ENDS 3. CONNECT END-TO-END TO FORM A CONTINUOUSCOLUMN

4. VESSEL ELEMENTS 1. MOST IMPORTANT FOR WATER TRANSPORT 2. DEAD 3. THICK, LIGNIFIED (AMORPHOUS POLYMERS) SECONDARY WALLS 4. NO CYTOPLASM AT MATURITY

5. 5. PITTED SECONDARY WALLS SO WATER CAN MOVE LATERALLY 6. ATTACHED END-TO-END LIKE TRACHEINDS & FORM A CONTINUOUS COLUMN

6. ANCIENT FLOWERING PLANTS HAD ONLY TRACHEIDS. • TODAY’S FLOWERING PLANTS HAVE ONLY VESSELS (MORE EFFICIENT) • CHECK CHART ON PAGE 253 ABOUT CELL PULL

7. ROOT PRESSURE (PUSH) AS IONS CONCENTRATE IN ROOTS CAUSES WATER TO MOVE INTO ROOTS

8. MOVEMENT OF ORGANIC MOLECULES - TRANSLOCATION PHLOEM • LIVING CELLS • COSIST OF SEIVE & COMPANION CELLS • CELLS CONNECTED BY SIEVE PLATES TO FORM A COMPLETE TUBE

9. 4. PLATES HAVE PORES TO ALLOW WATER & DISSOLVED ORGANIC MOLECULES THROUGH 5. COMPANION CELLS ARE CONNECTED BY PLASMODERMATA

10. 6. MOLECULES & WATER GO FROM SOURCE TO SINK 7. SOURE IS THE PRODUCER OF SUGARS BY PHOTOSYNTHESIS OR HYDROLYSIS OF STARCH (USUALLY THE LEAVES)

11. 8. SINK USES OR STORES SUGARS 9. USUALLY ROOTS, BUDS, STEMS SEEDS & FRUITS CHECK PICTURES ON PAGE 255 FOR PHLOEM CELLS STRUCTURE

12. 10. IN TUBERS & BULBS THE SINK OR SOURCE ARE SAME PLACE DEPENDING ON THE SEASON 11. ORGANIC MOLECULES DISSOLVED IN WATER IS PHLOEM SAP ( MOVES 1mhr¯)

13. 12. PHLOEM IS MOSTLY SUGARS (SUCROSE) AMINO ACIDS PLANT HORMONES mRNA WHICH EXPLAINS COMMUNICATION BETWEEN CELLS FAR APART

14. PRESSURE-FLOW HYPOTHESIS • SUGAR LEAVES SOURCE TO SEIVE TUBES • WATER CONC. REDUCES & OSMOSIS OCCURS FROM SURROUNDING CELLS • WATER UPTAKE IN SEIVE TUBE CAUSES BULK FLOW OF SAP

15. PRESSURE IS LESSENED IN SINK AS SUGAR LEAVES SEIVE TUBES • SUGAR CHANGES TO STARCH & ITS INSOLUBILITY EXERTS NO OSMOTIC EFFECT • XYLEM RECYCLES RELATIVELY PURE WATER BY TAKING IT FROM SINK BACK TO SOURCE

16. ONLY LOADING & REMOVAL OF SUGAR FROM SEIVE TUBE MEMBERS REQUIRES ENERGY • ACTUAL TRANSPORT IS PASSIVE