Disease causing Microorganisms in Humans – Notes Class 8

Disease-causing microorganisms in humans can be of different types such as bacteria, fungi, viruses, protozoa, etc. They enter the bodies of humans, plants, and animals, where they find hosts to inhabit. They rely on the host for nutrition. They start to multiply inside the host or human body and affect multiple cells causing diseases. In this article, you can find the disease-causing microorganisms in human notes.

Organisms that cannot be seen through the naked eye but only through a microscope are called microorganisms. Humans, plants, and animals suffer from various diseases caused by these microorganisms. Microbes can be single-celled or multicellular and can be harmful and useful to humans. These microorganisms may enter the body of humans directly or through some carriers or vectors such as mosquitoes, flies, etc.

For example, Dengue and malaria are spread by the virus carried by mosquitoes. Microorganisms are present almost everywhere in the world, from mountains to deep oceans and from the hot Sahara Desert to areas with temperatures below freezing point. We shall briefly discuss the uses of microorganisms and look at disease-causing microorganisms in detail.

As we discussed, various microorganisms are harmful to humans and causes diseases. These disease causing microorganisms are called pathogens and come in contact with humans through environmental factors such as air, water, and food. They may also travel from one person to another through direct or indirect contact. Diseases that travel through contact from an infected person to a healthy person are called communicable diseases. Examples common cold, TB, Hepatitis, etc.

The various disease causing microbes are:

Viruses

Viruses are small particles that can cause illness in humans by invading their cells and using them to multiply. They are responsible for various diseases such as the common cold, influenza, and COVID-19. When a virus enters the body, it attaches to cells and releases its genetic material, hijacking the host cell’s machinery to produce more viruses. This process can weaken the immune system and lead to symptoms like fever, cough, and fatigue.

Bacteria

Bacteria are microorganisms found everywhere; from soil to water to living organisms. Some bacteria are helpful, helping in digestion and producing essential nutrients, while others can cause diseases like strep throat, tuberculosis, and food poisoning. They typically attack the body by invading tissues or releasing toxins, leading to symptoms such as fever, inflammation, and organ damage. Antibiotics are commonly used to treat bacterial infections, but misuse can lead to antibiotic resistance. Regular handwashing and proper food handling help prevent bacterial infections.

Fungi

Fungi are a diverse group of organisms that include molds, yeasts, and mushrooms. They can cause various diseases in humans, such as athlete’s foot, ringworm, and yeast infections. Fungi typically attack by invading the body’s tissues or by producing toxins that harm the host. Infections can occur through contact with contaminated surfaces, inhalation of fungal spores, or ingestion of contaminated food. Proper hygiene and avoiding contact with sources of fungal contamination are important for preventing fungal infections.

Protozoa

Protozoa are single-celled organisms that can cause diseases in humans. Unlike bacteria, they are larger and possess complex cell structures. Common examples include Plasmodium, which causes malaria, and Giardia, responsible for gastrointestinal infections.

Also Read: Non-communicable Diseases -Types and its Prevention

Now, let us discuss the different diseases caused by microorganisms.

Apart from this, microorganisms also cause diseases in plants and animals. Some of these diseases are:

Some of the diseases caused by microorganisms in animals are:

Some of the diseases caused by microorganisms in plants are:

Apart from causing disease, microorganisms like fungi cause spoilage of food by growing on the surface of food. The fungi multiply very quickly on the food with time. If this spoilt food is consumed, it may cause food poisoning and may sometimes even lead to death. To avoid spoilage of food, various preservation techniques such as pickling, dehydration, etc. are used.

We can prevent the spread of diseases caused by microorganisms by following way:

• Wash hands regularly with soap and water.
• Cover mouth and nose when sneezing or coughing.
• Practice good hygiene, like cleaning surfaces often.
• Get vaccinated against common diseases.
• Cook food thoroughly and store it properly.
• Avoid close contact with sick individuals.
• Use insect repellent to prevent insect-borne diseases.
• Stay home when feeling unwell to prevent spreading illness.
• Follow public health guidelines and recommendations.

Also Read:

• NCERT Notes Class 8 Science Chapter 2: Microorganisms: Friend and Foe
• Disease Causing By Microorganisms in Animals and in Plants
• Medicinal Use of Microorganisms – CBSE Class 8
• Microbes and Disease
• Harmful Microorganisms – Examples, Types and Harmful Effects
• Microorganisms – Useful And Harmful

What are the Disease-Causing Microorganisms and Plants?

Disease-causing microorganisms include viruses, bacteria, fungi, and protozoa. In plants, bacteria, viruses, and fungi can also cause diseases.

What are the Disease Caused by Microorganisms Class 8?

Diseases caused by microorganisms in Class 8 typically include common illnesses like tuberculosis, typhoid, cholera, plague, ringworm, athlete’s foot, malaria, and others caused by bacteria, viruses, fungi, and protozoa.

What are the 4 Common Microorganisms that Cause Diseases?

The four common microorganisms that cause diseases are viruses, bacteria, fungi, and protozoa.

Name some Diseases Caused by Microorganisms in Plants.

Diseases such as yellow vein mosaic and rust of wheat are caused by microorganisms in plants.

How Pickling Helps in Preserving Food?

The process of pickling uses salt and oil. The use of salt removes moisture from the food and prevents the growth of microorganisms and oil cuts off the supply of fresh oxygen to the food item which helps to preserve the food.

What is Pasteurization?

The process of boiling milk at a high temperature for some time and then immediately cooling it is known as pasteurization.

Which Microorganism Causes TB? Which Part of the Body is Affected in the Disease?

TB or Tuberculosis is caused by bacteria. This disease affects the lungs and the respiratory system in humans and can also prove fatal.