The correct option is (c).
Explanation
Diseases are broadly classified into two categories based on their ability to spread: Communicable (Infectious) Diseases and Non-Communicable (Non-Infectious) Diseases. Communicable diseases are caused by pathogens such as bacteria, viruses, fungi, or parasites and can be transmitted from an infected host to a healthy individual.
Statement-wise Analysis
- Statement 1 is Incorrect. Communicable diseases are defined specifically by their ability to be transmitted from one person to another (or from animals to humans). Diseases that cannot be transmitted between individuals are known as Non-Communicable Diseases (NCDs), such as diabetes, hypertension, and cancer.
- Statement 2 is Correct. The transmission of infectious agents occurs through various modes. These include:
- Air: Droplet infection (e.g., common cold).
- Water and Food: Consumption of contaminated resources (e.g., cholera, typhoid).
- Vectors: Organisms like mosquitoes (e.g., malaria, dengue).
- Direct Contact: Physical contact with an infected person.
- Statement 3 is Correct.
- Tuberculosis (TB): A bacterial infection caused by Mycobacterium tuberculosis, primarily affecting the lungs and spreading through the air.
- Influenza: A viral infection attacking the respiratory system, spreading through droplets.
Key Takeaway
Communicable diseases are infectious and transmissible through agents like air, water, and vectors (e.g., TB, Flu), whereas Non-Communicable diseases are chronic, non-transmissible, and often related to lifestyle or genetics (e.g., Heart disease, Diabetes).