MICROANATOMY

Detailed explanation-1: -Cyanobacteria, which are also called blue-green algae are an ancient group of photosynthetic bacteria. Even though they’re called “blue-green algae” they’re actually bacteria. And bacteria are prokaryotic cells and they have no nucleus.

Detailed explanation-2: -Like other bacteria, cyanobacteria have no nucleus or internal membrane systems. In many species, however, the external membrane has been folded to increase total surface area. The “packets” created in the cell membrane by these foldings are the surfaces across which the chemical reactions of photosynthesis take place.

Detailed explanation-3: -Prokaryotic cells are primitive cells. They do not have well defined membrane bound nucleus. Nuclear material of a prokaryotic cell consists of a single chromosome which is in direct contact with cytoplasm. Here, the undefined nuclear region in the cytoplasm is called as nucleoid, i.e., there is no nuclear membrane.