The functional unit of the kidney is the: MCQ with Answer and Explanation

Explanation:
Salivary amylase (ptyalin) is secreted by salivary glands and begins starch digestion in the mouth, hydrolyzing starch into maltose and dextrins. It works optimally at neutral to slightly alkaline pH. Pancreatic amylase continues starch digestion in the small intestine. Pepsin digests proteins, trypsin digests proteins in the intestine, and lipase digests fats. Salivary amylase action stops in the acidic stomach.

Explanation:
Gastrin is a peptide hormone produced by the G cells (gastrin cells) located in the pyloric antrum of the stomach. Its primary function is to stimulate the parietal cells of the gastric glands to secrete hydrochloric acid (HCl) and the chief cells to secrete pepsinogen. This prepares the stomach for the digestion of food. Gastrin also stimulates gastric motility and growth of the gastric mucosa. Secretin and CCK stimulate the pancreas and gall bladder.

Explanation:
Bacterial cell walls (except Mycoplasma) contain peptidoglycan (murein), a polymer of N-acetylglucosamine and N-acetylmuramic acid cross-linked by short peptides. Chitin is in fungi and arthropods, cellulose in plants, hemicellulose in plant cell walls along with cellulose.