Which is not a major group of eukaryotic organisms?

• A. Protists
• B. Fungi
• C. Plants
• D. Monera

Answer: (D)

All eukaryotic organisms have cells with a nucleus and membrane-bound organelles, and they are grouped into major eukaryotic lineages such as protists, fungi, and plants (with animals as another major group in common classifications). Monera, on the other hand, refers to prokaryotes—organisms without a nucleus, like bacteria and archaea. Because prokaryotes lack a true nucleus and membrane-bound organelles, they are not considered eukaryotes. In modern taxonomy, Monera isn’t used as a major category; its members are split into Bacteria and Archaea, both prokaryotic. So the option that is not a major group of eukaryotic organisms is Monera.