In human biology, poliomyelitis (polio) is caused by which type of microorganism?

Introduction / Context:

Poliomyelitis, commonly known as polio, is a classic topic in human biology and general knowledge examinations. The disease gained global attention in the twentieth century because it caused paralysis in many children before vaccines were widely introduced. Understanding the type of microorganism that causes polio is important because prevention and treatment strategies depend on whether the agent is a bacterium, virus, fungus, protozoan, or some other pathogen. This question tests basic recall of infectious disease classification and helps students connect vaccination programmes with the underlying biology of the disease.

Given Data / Assumptions:

• The disease in question is poliomyelitis, commonly shortened to polio.
• We are asked specifically for the type of microorganism that causes polio.
• The options include different groups of microbes: bacterium, virus, fungus, protozoan, and helminth.
• We assume standard school and entrance exam level classification of microbes.

Concept / Approach:

The concept required here is the basic classification of disease causing organisms. Microorganisms are broadly grouped as bacteria, viruses, fungi, protozoa, and helminths (parasitic worms). Many human diseases are associated with a specific group. For example, tuberculosis is caused by a bacterium, ringworm by a fungus, malaria by a protozoan, and ascariasis by a helminth. Polio is well known as a viral disease, and the vaccines used worldwide are specifically polio virus vaccines. Therefore, the student must recall that polio is caused by a virus, not by bacteria or any other group.

Step-by-Step Solution:

Step 1: Identify the disease mentioned in the question, which is poliomyelitis or polio. Step 2: Recall from basic biology that polio affects the nervous system and can cause paralysis, particularly in children. Step 3: Connect polio with vaccination campaigns such as oral polio drops, which are designed to protect against a virus. Step 4: Compare this information with the options given: bacterium, virus, fungus, protozoan, and helminth. Step 5: Conclude that the causative agent of polio is the polio virus, so the correct group is Virus.

Verification / Alternative check:

A quick verification can be done by remembering that the name of the causative organism is poliovirus, which clearly includes the word virus. Standard biology and public health textbooks also list polio under viral diseases, not bacterial or fungal diseases. Additionally, the oral polio vaccine and inactivated polio vaccine are described as viral vaccines, confirming that the underlying pathogen is a virus. This cross checking from different learning sources supports the same conclusion.

Why Other Options Are Wrong:

Option A, Bacterium, is incorrect because polio is not caused by bacteria; bacterial diseases include tuberculosis, typhoid, and cholera. Option C, Fungus, is wrong because fungal infections usually involve skin, nails, or mucous membranes, such as ringworm and athlete foot. Option D, Protozoan, is incorrect since protozoan diseases include malaria and amoebiasis, not polio. Option E, Helminth (worm), is also wrong because helminths are parasitic worms like Ascaris and tapeworm and do not cause polio.

Common Pitfalls:

One common mistake is to confuse any infectious disease with bacteria, because many students are more familiar with bacterial infections. Another error is mixing up polio with other childhood diseases like measles or mumps and forgetting which ones are viral. Some learners pay more attention to vaccine names than to pathogen classification and may not explicitly connect poliovirus with the group virus. Careful reading and repeated revision of disease tables in textbooks helps avoid these mistakes.

Final Answer:

The correct causative group for poliomyelitis is a Virus.