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

The tapetum is a nutritive layer within the anther that provides essential nutrients and materials for the developing pollen grains (male gametophytes). A malfunctioning tapetum would be unable to supply these necessary components, leading to the failure of pollen grain development and thus resulting in non-viable male gametophytes.