NCERT Exemplar for Class 9 Science Chapter 13 - Why Do We Fall ill (Book Solutions)

NCERT Exemplar for Class 9 Science - Why Do We Fall ill - Free PDF Download

Free PDF download of NCERT Exemplar for Class 9 Science Chapter 13 - Why Do We Fall ill solved by expert Science teachers on as per NCERT (CBSE) Book guidelines. All Chapter 13 - Why Do We Fall ill exercise questions with solutions to help you to revise the complete syllabus and score more marks in your examinations. Every NCERT Solution is provided to make the study simple and interesting on Vedantu. Subjects like Science, Maths, English will become easy to study if you have access to NCERT Solution for Class 9 Science , Maths solutions and solutions of other subjects. You can also download NCERT Solutions for Class 9 Maths to help you to revise complete syllabus and score more marks in your examinations.

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NCERT Exemplar for Class 9 Science chapter 13 part-1

Overview of NCERT Class 9 Science Chapter 13 - Why Do We Fall ill

NCERT Exemplar Solutions for Class 9 Science Chapter 13 Why Do We Fall Ill is an important study material for Class 9 students because it has a high examination mark value.  In competitive examinations, questions from this chapter are frequently asked.  Students who wish to take biology in higher studies should study this NCERT Exemplar thoroughly so that they have a good command over the topic quickly. After completing extensive research on each topic, the NCERT Exemplar Solutions for Class 9 Science Chapter 13 are created by highly experienced professors. Students can use these solutions to acquire a broad understanding of the concepts covered in this chapter while working on the textbook questions. 

The answers to the questions in the NCERT Exemplar book are included in this NCERT Exemplar Solutions Class 9 Science book. To acquire the answers, head over to Students can access the solutions both online and offline, depending on their needs. On Vedantu, solutions are provided in PDF format, which students can download and use to get their questions answered quickly. 



  • 13.1 Health and it’s failure

  • 13.2 Disease and its causes

  • 13.3 Infectious and non- infectious diseases

  • 13.4 Principle of treatment and prevention

Important Topics for NCERT Exemplar Class 9 Science Solutions


The state of being socially, physically, and mentally healthy so that the body can function effectively is referred to as health.


A disturbance in the function or structure of any part or organ of the body is referred to as disease. Diseases can be caused by germs or viruses, or by a lack of a nutritious diet, among other things.

Types of Diseases

There are two types of diseases:  infectious and non-infectious.

  1. Acute illnesses such as the flu, the common cold, and others

  2. Chronic diseases such as tuberculosis, cancer, and others


Antibiotics are a type of drugs or medicines that work to prevent bacteria from body using metabolic pathways that are essential for their survival. These treatments will never function against viral infections because viruses lack their own biochemical system, yet everything is still dependent on the host.

Transmission Methods of Infectious Disease

Infectious diseases are conveyed primarily through water, food, air, and direct contact from an infected person to a healthy one.

Approaches Towards Treatment  

 There are primarily two principles of infectious diseases.  Their main objective is to:

  • Reduce the severity of the signs and symptoms

  • Kill the bacteria that are responsible for the illnesses.

Principles of  Prevention

Infectious infections can be prevented in one of two ways:

  • Preventive measures in general

  • Prevention methods in specific

Few things to keep in mind from this Chapter:

  • The term "health" refers to one's physical, mental, and social well-being.

  • The physical environment has an impact on an individual's health.

  • The two main kinds of diseases are acute and chronic.

  • Infectious and noninfectious diseases are caused by a variety of factors.

  • Infectious agents are conveyed through air, water, personal touch, and other means.

  • A fact to live by "Prevention is always better than cure."

  • By minimising the exposure to infectious agents, public health hygiene measures prevent the spread of infectious diseases.

FAQs (Frequently Asked Questions)

1. What are the most important topics to study in NCERT Exemplar for Class 9 Science Chapter 13?

This chapter delves into the specifics of why you fall ill. This chapter is fascinating since it informs us about the human body and its possibilities. The following are some of the important topics covered in this chapter:

  • Health

  • Diseases 

  • Types of diseases

  • Antibiotics

  • Transmission methods

  • Approaches towards treatment

  • Prevention methods

For your convenience, The NCERT Exemplar for Class 9 Science - Why Do We Fall Ill will undoubtedly serve as the ideal reference study material for you because it includes all of the modified solutions that make this chapter simple to comprehend.

2. What is a disease? How many types of diseases are there according to NCERT Exemplar for Class 9 Science Chapter 13?

Each organ in an organ system serves a distinct purpose. When this function is disrupted or altered, a condition known as disease develops. These alterations have an unfavourable influence on the body's regular functioning, and the changes are referred to as signs and symptoms of a disease. Diseases are primarily caused by germs, viruses, bacteria, lack of nutritional diet, lack of personal hygiene, and so other causes. 

3. How many types of diseases are there mentioned in NCERT Exemplar for Class 9 Science Chapter 13?

Types of diseases mentioned in book are:

  • Acute diseases: Those that last for only a few days or weeks. 

  • Chronic diseases: Those that last for an extended period of time, sometimes even a lifetime. 

  • Infectious diseases: Diseases that are caused by bacteria. Vectors or other ways such as air, food, and water can spread these diseases from one person to another.

  • Non-Infectious Diseases: Diseases that are not caused by infectious agents. Their causes differ, but they are not external factors such as bacteria that might spread throughout a population. Internal, non-infectious reasons are the most common. 

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