Q.Graft between identical twins is called :

Immunology is the study of the immune system — the body's coordinated defence against infectious and other foreign agents. The overall capacity to resist disease-causing pathogens is called immunity (or disease resistance); its absence is susceptibility. A healthy immune system reacts specifically and destructively toward molecules that are foreign to the body (non-self) while normally sparing the body's own molecules (self); any foreign macromolecule — typically a protein, polysaccharide or nucleic acid — capable of triggering this reaction is called an antigen. When self/non-self discrimination breaks down, the immune system can attack the …