Person $^{\prime}A^{\prime}$ 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 as baby in a bubble syndrome. Identify the disease, this person $^{\prime} A ^{\prime}$ is suffering from
Cystic fibrosis
Diabetes
$AlDS$
$SCID$
Read the following sentences and choose correct sentences
$1.$ Dysentery, plague, diphtheria are caused by bacteria
$2.$ Salmonella typhi directly affect the respiratory system
$3.$ Amoebiasis and Ascariasis are caused by contaminated water
$4.$ Internal bleeding, anemia muscular pain are symptoms of elephantiasis
Widal test is used for the diagnosis of
The poisons produced in the body by bacteria are called
The function of $IgE$ is