The part of the human digestive system where most chemical digestion and absorption occurs is the: MCQ with Answer and Explanation

Explanation:
Somatostatin is a powerful, universal inhibitory peptide hormone. In the gastrointestinal tract and pancreas, it is secreted by the Delta (D) cells of the pancreatic islets and the D cells of the gastric and intestinal mucosa. Its primary role in the GI tract is to act as a paracrine inhibitor, suppressing the release of almost all other gastrointestinal hormones, including gastrin, secretin, cholecystokinin (CCK), vasoactive intestinal peptide (VIP), and gastric inhibitory peptide (GIP). It also inhibits gastric acid secretion, pancreatic enzyme secretion, and intestinal motility, acting as a 'brake' on the digestive system.

Explanation:
The glomerulus is a tuft of fenestrated capillaries enclosed by the Bowman's capsule in the renal corpuscle. Blood is filtered under high pressure through the capillary walls into the Bowman's space. The filtrate then passes into the nephron tubules. Glomerular filtration is the first step in urine formation.

Explanation:
The primary cell wall of plants consists of cellulose microfibrils embedded in a matrix of hemicellulose, pectin, and proteins. Secondary walls contain lignin. Chitin is in fungi and arthropods, peptidoglycan in bacteria. Cellulose is a polymer of β-glucose units and provides structural support.