Question

(a) Do all pollen grains remain viable for the same length of time ? Support your answer with two suitable examples.
(b) How are pollen grains stored in pollen banks ? State the purpose of storing pollen grains in these banks.

Answer 1

(a) No 
Examples :
(i) Cereals / rice / wheat - pollen grains / loose viability with in thirty minutes of their release 
(ii) In some members of Rosaceae / leguminoseae / Solanacease maintain viability for months 
(b) Using cryopreservation techniques / in liquid nitrogen (-196° C) 
Maintaining viability / preserving threatened species / preserving commercially important
plants / to be used for crop breeding programmes