Which of the following hormones is responsible for the closure of stomata during water stress? MCQ with Answer and Explanation

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:
Rudolf Virchow, in 1855, added the third tenet to the cell theory: 'Omnis cellula e cellula', meaning all cells arise from pre-existing cells. Schleiden and Schwann proposed that plants and animals are composed of cells (first two tenets). Robert Hooke discovered cells. Virchow's concept refuted spontaneous generation and established the continuity of life.

Explanation:
The pancreas is a mixed gland: exocrine acini secrete digestive enzymes (trypsin, lipase, amylase) into the duodenum, while endocrine islets secrete insulin and glucagon into the blood. The liver produces bile, not digestive enzymes. Spleen filters blood, gall bladder stores bile.