Consider statements about scientists: 1. Robert Hooke discovered cells. 2. Antonie van Leeuwenhoek discovered bacteria. 3. Charles Darwin proposed the cell theory. Which are correct? MCQ with Answer and Explanation

Explanation:
Galanin is a 29-amino acid neuropeptide that is co-localized with several other neurotransmitters and hormones. In the central nervous system, it is involved in various functions, including the inhibition of acetylcholine release and modulation of pain. In the gastrointestinal tract and pancreas, its primary functions are inhibitory: it inhibits the release of both insulin and glucagon from the pancreatic islets, inhibits gastric emptying and gastric acid secretion, and generally inhibits intestinal motility and secretion. It acts to slow down digestion and nutrient absorption.

Explanation:
George Beadle and Edward Tatum irradiated Neurospora crassa and showed that mutations in specific genes caused defects in specific enzymes, leading to the one gene-one enzyme concept. Watson and Crick discovered DNA structure, Mendel laws of inheritance, Morgan chromosome theory.

Explanation:
Seed dispersal spreads seeds away from the parent plant, reducing competition for light, water, nutrients, and space. It also aids in colonization of new habitats and increases species distribution. Dispersal agents include wind, water, animals, and explosive mechanisms. Overcrowding would lead to resource limitation. Genetic diversity is promoted by cross-pollination, not directly by dispersal.