Different diseases caused by different microorganisms are

Microorganisms Name

Disease Caused

Bacteria

Cholera,Typhoid,TB (Tuberculosis)

Fungi

Ringworm and Athlete's food 

Protozoa

Dysentery,Malaria

Algae

N/A

Virus

Polio ,Chicken Pox, Hepatitis,Aids

 

 

 

 

Some diseases are spread from an infected person to a healthy person. They can be spread through air, water, food, physical contact

Such diseases are called communicable diseases

Example - Cholera, Cold, Chicken pox

 

 

How do Pathogens cause communicable disease?

When a person suffering from cold sneezes,drops of moisture  are spread in air. These drops contain thousands of virus,

When it reaches healthy person,he gets infected

These can also be spread by

  • Physical contact(Touching an inected person)
  • Water(Drinking water from Same Utensil)
  • Food(Eating food from same utensil)

 

 

What are carriers of Disease causing microbes?

Some insects and animals carry harmful microorganisms (pathogens) on them

Example

Housefly

They sit on garbage and waste

Harmful micro organsims called pathogens stick to their body

When they later sit on food,they drop these pathogens on food

When person eats this food,pathogens enter body and cause diseases

Housefly.jpg

 

Mosquito

Mosquito’s cause diseases like malaria or dengue.

Female Aedes mosquito acts as carrier of dengue virus

Female Anopheles mosquito acts as carrier of malaria parasite(plasmodium)

When they bite human being,they transfer this virus/parasite in human being causing disease

Female Aedes mosquito - Female Anopheles mosquito - Merge.jpg

 

 

 

How to Prevent Different Diseases caused by Microorganisms

 

DISEASE NAME

CAUSED BY

HOW TO PREVENT

Malaria

It is caused by Protozoa

It is transmitted by Mosquito

  • Use Mosquito spray
  • Do not allow water to collect so that mosquitos do not breed
  • Use mosquito net when sleeping
  • Keep surroundings clean and dry

Dengue

It is caused by Virus.
It is transmitted by Mosquito

Hepatitis A

Hepatitis B

They are caused by Virus

They are transmitted by Water

Drink Boiled Water (boiling kills microorganisms)

Vaccination should be done

Cholera and Typhoid

They are caused by bacteria

Typhoid is transmitted by water

Cholera is transmitted by both food and water

Maintain good personal hygiene

Boil water

Eat properly cooked food

Tuberculosis




They are caused by bacteria.
Transmitted by air

It is a communicable disease

So keep patient in isolation

Keep belongings of patient separate

Vaccines should also be given

Measles

They are caused by virus.
Transmitted by air

Chicken Pox

They are caused by virus.
Transmitted by air or by contact

Polio

They are caused by virus
Transmitted by air or by water

 

Questions

NCERT Question 1 (d) - Cholera is caused by __________.

View Answer

 

NCERT Question 2 (d) - Tick the correct answer:

The most common carrier of communicable diseases is

(i) ant (ii) housefly (iii) dragonfly (iv) spider

View Answer

 

NCERT Question 3 - Match the organisms in Column I with their action in Column II

Column II

Column II

(i) Bacteria

(a) Fixing Nitrogen

(ii) Rhizobium

(b) Setting of curd

(iii) Lactobacillus

(c) Baking of bread

(iv) Yeast

(d) Causing Malaria

(v) A protozoan

(e) Causing Cholera

(vi) A Virus

(f) Causing AIDS

 

(g) Producing antibodies

View Answer

 

NCERT Question 8 - Write a short paragraph on the harms caused by microorganisms

View Answer

 

NCERT Question 5 - What are the major groups of microorganisms?

View Answer

 

NCERT Question 2 (c) - Tick the correct answer:

Carrier of malaria-causing protozoan is

(i) female Anopheles mosquito (ii) cockroach

(iii) housefly (iv) butterfly

View Answer

  1. Class 8
  2. Chapter 2 Class 8 - Microorganisms : Friend and Foe

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.