In pollen banks, pollen grains of many species can be stored for many years in:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Liquid nitrogen (-196°C)
Pollen grains of many species can be stored for years in liquid nitrogen at −196°C. At this very low temperature the pollen stays alive. Such stored pollen forms pollen banks, like seed banks, and is used in crop breeding programmes. Sperms of many animals, including humans, are also stored in the same way for artificial insemination.
(1) Liquid oxygen (-196°C) — Incorrect. Liquid oxygen is not used for storing pollen.
(2) Liquid hydrogen (-96°C) — Incorrect. Liquid hydrogen is not used for storing pollen.
(3) Liquid nitrogen (-196°C) — Correct. Pollen banks use liquid nitrogen.
(4) Liquid carbon dioxide (-196°C) — Incorrect. Liquid carbon dioxide is not used for storing pollen.
NCERT Extract:
Stamen, Microsporangium and Pollen Grain – “… In some cereals such as rice and wheat, pollen grains lose viability within 30 minutes of their release, and in some members of Rosaceae, Leguminoseae and Solanaceae, they maintain viability for months. You may have heard of storing semen/ sperms of many animals including humans for artificial insemination. It is possible to store pollen grains of a large number of species for years in liquid nitrogen (-1960C).”