Which of the following reasons is mainly responsible for graft rejection in transplantation of organs?

Which fish selectively feed on larvae of mosquitoes?

In higher vertebrates, the immune system can distinguish between self-cells and non-self. If this property is lost due to genetic abnormality and it attacks self–cells, then it leads to:

During injury, mast cells secrete:

During viral infection, the protein formed in host cells to resist is:

Cirrhosis of the liver is caused by the chronic intake of:

Which one of the following acts as a physiological barrier to the entry of microorganisms in a human body?

To which type of barriers under innate immunity, do the saliva in the mouth and the tears from the eyes, belong?

Short-lived immunity acquired from mother to foetus across the placenta or through mother's milk to the infant is categorised as: