Identify the chemical structure given below.

$A$: Newer antibiotics are required to be produced regularly.
$R$: Pathogens often develop resistance to existing antibiotics.

In most cities of India,what are the majority of children suffering from?

Identify the number of correct statements from the following:
$(1)$ Gene therapy is used in the treatment of $ADA$ deficiency.
$(2)$ Tetanus causes sustained muscle contraction. There is a lack of relaxation phase.
$(3)$ Cigarette smoking leads to asthma in the respiratory system.
$(4)$ $A$ transplanted kidney in a patient can fail due to cell-mediated immunity.
$(5)$ Serum globulin is an antibody.

Which medicinal drugs are obtained from the given figures $A$ and $B$?

In the given diagram of the life cycle of Plasmodium in the mosquito,what does the part labeled '$a$' represent?