Which one of the following is not eukaryotic?
Monera
Monera is prokaryotic as they do not have a well-defined nucleus. All the organisms of this kingdom are prokaryotes. Complex structure was the basis of classification of organisms, many centuries ago. According to R.H. Whittaker's five kingdom classification, all the bacteria were placed under the Kingdom Monera. Monera is considered as the most primitive group of organisms. They include various types of bacteria and blue-green algae. Monerans are most abundant of all organisms, due to the versatility of their habitat. It is estimated that a single drop of water contains 50 billion bacteria.