The 'first line of defence' is known as:

Assertion: Interferons are a type of antibodies produced by body cells infected by bacteria.
Reason: Interferons stimulate inflammation at the site of injury.

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

Given below are two statements:
Statement $I:$ Autoimmune disorder is a condition where the body's defense mechanism recognizes its own cells as foreign bodies.
Statement $II:$ Rheumatoid arthritis is a condition where the body does not attack self-cells.
In the light of the above statements,choose the most appropriate answer from the options given below:

Person '$A$' cannot step out of his house. He has to spend his entire life in sterile isolation; otherwise, he would quickly contract a fatal infection. This person has almost no effective immune system. This disease is also called '$baby$ $in$ $a$ $bubble$ $syndrome$'. Identify the disease this person '$A$' is suffering from.

When children without $T-$ cells and $B-$ cells are kept in germ-free isolation suits,the disease is known as: