The scientist who proposed the 'one gene-one enzyme' hypothesis was: MCQ with Answer and Explanation

Explanation:
Howard Temin and David Baltimore independently discovered reverse transcriptase in retroviruses in 1970, an enzyme that synthesizes DNA from RNA. Watson and Crick DNA structure, Mullis PCR.

Explanation:
Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide that acts as a neurotransmitter and a hormone. In the gastrointestinal tract, its primary functions are stimulatory and relaxant: it stimulates the secretion of water and electrolytes into the intestinal lumen (acting as a secretagogue), relaxes the smooth muscle of the gut (including the lower esophageal sphincter, stomach, and gall bladder), and stimulates the pancreas to secrete a bicarbonate-rich juice. It also causes vasodilation in the gut. Excessive VIP secretion can lead to severe watery diarrhea (as in VIPoma).

Explanation:
The pyloric sphincter is a ring of smooth muscle at the junction of the stomach and duodenum. It controls the release of chyme from the stomach into the small intestine in small amounts. The cardiac sphincter is between the esophagus and stomach, ileocecal valve between small and large intestine.