'Smack' is a drug obtained from the:

Which of the following are the reason(s) for Rheumatoid arthritis? Choose the correct option.

i. The ability to differentiate pathogens or foreign molecules from self cells increases.

ii. Body attacks self cells

iii. More antibodies are produced in the body

iv. The ability to differentiate pathogens or foreign molecules from self cells is lost

AIDS is caused by HIV. Among the following, which one is not a mode of transmission of HIV?

The substance produced by a cell in viral infection that can protect other cells from further infection is:

Transplantation of tissues/organs to save certain patients often fails due to rejection of such tissues/organs by the patient. Which type of immune response is responsible for such rejections?