Kingdom Monera consists of prokaryotic organisms like bacteria and cyanobacteria. The key characteristic of prokaryotes is that they lack membrane-bound organelles such as nucleus, mitochondria, or endoplasmic reticulum. Option B incorrectly states they have 'well-defined cell organelles,' which is false and therefore the correct answer to this 'not correct' question. Monera can have cell walls (but not always made of peptidoglycan), can be autotrophic or heterotrophic, and are indeed prokaryotic.