CBSE Class 12 Biology — Human Health and Disease

Which of the following is not a component of immune system ?

(a) Define Humoral immune response. [1] (b) Name any two types of antibodies found to give humoral immune response in humans. [1]

(a) Mention the scientific name of the source plant and the part from which opioids are extracted. [1] (b) How are morphine and heroin related? Mention the effect each one of them has on human body. [2]

(a) (i) Name the protozoan species that is responsible for causing the most serious and even fatal malarial disease. [½] (ii) Name the host in which the parasite completes its sexual stages and explain the changes taking place. [2] (iii) How does the parasite damage the human body after entering the blood stream? [1½] (iv) Suggest two effective preventive measures to control the spread of this disease in endemic regions. [1] OR (b) (i) What are bio-fertilizers? [1] (ii) Name the different types of microorganisms used as bio-fertilizers in organic farming and explain how each contributes to soil fertility. [3] (iii) Write two advantages of using bio-fertilizers over chemical fertilizers. [1]