Question

How are pollen grains stored in pollen banks?

Hint:

The specific value \(-196^{\circ}\text{C}\) is a very common objective question. Always specify "Liquid Nitrogen" along with the temperature.

Answer 1

Step 1: Understanding the Concept:
Long-term storage of biological material at extremely low temperatures is called cryopreservation. This allows the preservation of genetic diversity.
Step 2: Detailed Explanation:
Pollen grains can be stored for many years in "pollen banks."
The process involves placing the pollen in liquid nitrogen at a constant temperature of \(-196^{\circ}\text{C}\).
At this temperature, all metabolic activities of the pollen grain effectively stop, preventing degradation and maintaining viability for an indefinite period.
This stored pollen can later be used in plant breeding programs.
Step 3: Final Answer:
Pollen grains are cryopreserved in liquid nitrogen at \(-196^{\circ}\text{C}\) for long-term storage in pollen banks.