Human Health and Disease — BIOLOGY STD 12 Science — Question

→Many organisms like bacteria, viruses, fungi, parasites, worms are responsible for causing diseases in humans. Such disease causing organisms are called pathogens.
→All parasites are pathogenic because they harm the host by staying in or on it. Pathogens enter our body in many ways, multiply, disturb our essential functions.
→As a result, external and functional impairment occurs.
→Pathogen has to adapt its life according to the internal environment of the host.
→Shows ability to survive in pH (<7) and resist various digestive enzymes.
Examples:

	Disease	Pathogens
1	Typhoid	Salmonella typhi
2	Pneumonia	Streptococcus pneumoniae, Haemophilus influenzae
3	Common cold	Rhino viruse
4	Malaria	Plasmodium species
5	Ascariasis	Ascaris lumbricoid
6	Elephantiasis/ Filariasis	Wuchereria bancrofti
7	Ringworm	microsporum, trichophyton & Epidermophyton