Rennin is found in:

As $HCl$ is to $Pepsinogen$,so is $......$ to $Trypsinogen$.

The secretin promotes the release of

Identify the type of gastrointestinal hormone based on the functions given below:
$I.$ Stimulates the crypts of Lieberkuhn
$II.$ Inhibits the secretion of glucagon by alpha cells
$III.$ Stimulates Brunner's glands to release mucus
Choose the correct option accordingly.

The secretion of digestive juices is controlled by which of the following?

If the $pH$ of a protein is $1.6$, which enzyme will digest it?