Which of the following groups of cells is devoid of true nuclei?

Step 1: Analyze the question The question asks which group of cells has no true nucleus. A cell without a true (membrane-bound) nucleus is called prokaryotic.

Step 2: The concept

• Prokaryotes have no membrane-bound nucleus. Their genetic material (DNA) lies free in the cytoplasm in a region called the nucleoid. They also lack membrane-bound organelles such as mitochondria. Examples are bacteria and blue-green algae (cyanobacteria).
• Eukaryotes have a true nucleus enclosed by a nuclear membrane, plus membrane-bound organelles. Examples are plants, animals, fungi, protozoans and most algae.

In the Five Kingdom classification, Kingdom Monera contains the prokaryotes: bacteria and cyanobacteria.

Step 3: Check each option

• A. Algae: Most algae (green, red, brown) are eukaryotic and have true nuclei. Only the blue-green "algae" are prokaryotic, but they are properly classified under Monera as cyanobacteria. So algae as a group is not the answer.
• B. Monera: Prokaryotic, with no true nucleus. ✔
• C. Fungi: Eukaryotic, with true nuclei (e.g. yeast, mushrooms, Rhizopus).
• D. Viruses: These are not cells at all. They have no cytoplasm or nucleus, only genetic material in a protein coat. The question asks about groups of cells, so viruses are excluded.

Step 4: Answer The correct option is B. Monera.

Exam tip: Remember "Monera = No nucleus." Whenever you see "no true nucleus" or "prokaryote," think bacteria and blue-green algae, which belong to Monera. Also watch for the word "cells": viruses are acellular, so they are not the answer to a question about cells.