Biologically most resistant plant material is

Pollen tablets are available in the market for

Select incorrect statement regarding microsporogenesis in an anther

If there are four cells in a anther, what will be the number of pollen grains?

The odd one is

Assertion : If pollen mother cells has $42$ chromosomes, the pollen has only $21$ chromosomes.
Reason : Pollens are formed after meiosis in pollen mother cell.