Ch 6Biology and Human Welfare — Class 11 Zoology, concept-first.

Living organisms rarely live in isolation. Many species have evolved close, long-term associations with other species, and one of the commonest of these associations is parasitism — a relationship in…

Entamoeba histolytica is a microscopic, unicellular protozoan parasite that lives in the large intestine (colon) of humans and is the causative organism of amoebiasis, commonly known as amoebic dysent…

Plasmodium vivax is a sporozoan protozoan parasite and one of the principal causative agents of malaria in India.

Ascaris lumbricoides, commonly called the giant intestinal roundworm, is one of the largest and most common nematode parasites of the human small intestine, and the causative agent of ascariasis.

Wuchereria bancrofti is a slender, thread-like nematode parasite that lives in the human lymphatic system and is the principal cause of lymphatic filariasis, popularly known as elephantiasis in its ad…

Alongside the four major parasitic infections detailed in this chapter, several other infectious diseases caused by bacteria, viruses and fungi are of everyday public-health importance.

Public health is the organised effort of society, communities and individuals to prevent disease, prolong life, and promote physical and mental well-being, rather than simply treating illness after it…

Beyond infectious disease, this chapter also surveys a very different but equally serious threat to human welfare: the misuse of tobacco, alcohol and psychoactive drugs, collectively referred to as TD…

Sample papers and previous-year board questions for this subject.