Identify $X$ from the given figure.

What is the function of $T_S$ (Suppressor $T$-cells) in the body?

Which of the following cells act as phagocytes?

Which type of antibody is transferred from the mother to the fetus through the placenta?

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

Which type of innate immunity barrier is represented by the secretion of saliva from the mouth and tears from the eyes?