An anther with malfunctioning tapetum often fails to produce viable male gametophyte. Give any one reason. 

How many microspore mother cells would be required to produce one hundred pollen grains in a pollen sac? And why?

How many microsporangia are present in a typical anther of an angiosperm?

How do flowers of Vallisneria get pollinated?

How many pollen grains and ovules are likely to be formed in the anther and the ovary of an angiosperm bearing 25 microspore mother cells and 25 megaspore mother cells, respectively.