Class IX :: Chapter 13 - WHY DO WE FALL ILL
Chapter-wise Multiple Choice Questions with Instant Feedback
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- Health: State of complete physical, mental, and social well-being, not just absence of disease.
- Disease: Condition that impairs normal functioning of the body, caused by various factors.
- Acute Diseases: Short duration (e.g., common cold, typhoid).
- Chronic Diseases: Long-lasting, cause prolonged damage (e.g., TB, elephantiasis).
- Infectious Diseases: Caused by pathogens; can spread (communicable).
- Non-infectious Diseases: Caused by internal factors; do not spread (non-communicable).
- Pathogens: Disease-causing microbes (viruses, bacteria, fungi, protozoa, worms).
- Means of Spread: Air, water, sexual contact, vectors (e.g., mosquitoes).
- Organ-specific Manifestations: Symptoms depend on the organ affected (e.g., cough in TB, jaundice in hepatitis).
- Principles of Treatment: Reduce symptoms, kill microbes (antibiotics for bacteria, antivirals for viruses).
- Principles of Prevention: Public hygiene, vaccination, proper nutrition, avoiding exposure.
- Vaccination: Stimulates immune memory to prevent future infections.
- Antibiotics: Work against bacteria by blocking their life processes; ineffective against viruses.
- Immune System: Body’s defense mechanism; weakened in HIV/AIDS.
- Vectors: Animals that carry pathogens (e.g., Anopheles mosquito for malaria).
Basic Level Questions
Chapter Summary
Chapter 13, "Why Do We Fall Ill", explores the fundamental concepts of health, disease, and the factors that influence our well-being. It moves beyond the simple idea of "being sick" to understand health as a holistic state and disease as a disruption caused by various biological, social, and environmental factors.
This chapter is a high-scoring, concept-driven segment of the Class 9 Science syllabus, vital for board exams and foundational for competitive tests like NTSE and future medical entrance exams. It requires no complex calculations but tests your clarity on definitions, classifications, cause-effect relationships, and preventive measures. Questions often ask you to distinguish between disease types, identify pathogens and vectors, explain symptoms, and justify treatment approaches—making conceptual mastery key to answering accurately and scoring full marks.
Our platform transforms your theoretical understanding into exam-ready confidence. We offer a structured progression of MCQs—from basic definitions to complex, application-based scenarios—mirroring exactly what you'll face in your exams. By practicing here, you reinforce key distinctions (e.g., acute vs. chronic, viral vs. bacterial), internalize transmission pathways, and master preventive strategies. This targeted, repetitive testing builds speed, eliminates common misconceptions, and ensures you can tackle any question on this chapter with clarity and precision, turning important health concepts into guaranteed marks.