The polio vaccine was developed by:

An insect regarded as the greatest mechanical carrier of disease is

Organophosphates inhibit the enzyme cholinesterase. Which of the following is a cholinesterase inhibitor?

The biological agents of disease include

$DPT$ vaccine doses are administered at specific intervals after birth. Identify the correct sequence for the $1^{st}$, $2^{nd}$, and $3^{rd}$ doses of $DPT$ from the following list:
$I$. $6 \; \text{weeks}$ after birth
$II$. $10 \; \text{weeks}$ after birth
$III$. $14 \; \text{weeks}$ after birth
$IV$. $24 \; \text{weeks}$ after birth
$V$. $29 \; \text{weeks}$ after birth

Assertion $(A)$: Aflatoxins are produced by $Aspergillus$ $flavus$.
Reason $(R)$: These toxins are useful to mankind.