Nuclear mebrane is absent in (1) Penicillium (2) Agaricus (3) Volvox (4) Nostoc
Nostoc is a prokaryote. Prokaryotic cells lack membrane-bound organelles and well-organized nucleus, that is nuclear envelope is absent in these cells. The nuclear envelope, also known as the nuclear membrane, bilayer membranes that surround the nucleus, and in eukaryotic cells it encases the genetic material.