K.C.S.E Biology Q & A - MODEL 2014PP1QN26

K.C.S.E Biology Q & A - MODEL 2014PP1QN26

The table provided shows the concentration of sodium and iodine in sea water and cell sap of a plant.

​(a) (i) Name the process through which the plant cells take up sodium ions. 
(ii) Give a reason for your answer in (a) (i) above. 
(b) If the plant was sprayed with a chemical that inhibits respiration:
(i) which of the two ions uptake will be affected’? 
(ii) give a reason for your answer in (b) (i) above.

ANSWERS

​(a) (i) Diffusion; 
(ii) Sea water contains a higher concentration of sodium ions than the cell sap;
(b) (i) Iodide ions; 
(ii) Sea water has a lower concentration of iodide ions than the cell.
The plant requires energy to take up the iodide ions (by active transport);