Question

How tapetal cells could become bi-nucleate??

Answer 1

The deepest divider layer of microsporangium is known as tapetum, it gives sustenance to the developing microspores. cells of tapetum have thick cytoplasm and by and large have more than one nucleus. 

Tapetal cells are enormous cells which have more than one nucleus. They help in development and improvement of dust grains. Tapetal cells experience endomitosis in which nucleus separates inside a nuclear membrane, however, cytokinesis does not happen. On account of which they move toward becoming bi/multinucleate.