Consider statements about human senses: 1. The retina contains photoreceptors. 2. The cochlea is involved in hearing. 3. Taste buds are located only on the tongue. Which are correct? MCQ with Answer and Explanation

Explanation:
Gastric Inhibitory Peptide (GIP), now more commonly called Glucose-dependent Insulinotropic Peptide, is an incretin hormone secreted by the K cells of the small intestine in response to the ingestion of food, particularly glucose and fats. Its name reflects its two main actions: 1) It inhibits gastric acid secretion and slows gastric emptying (the 'gastric inhibitory' effect). 2) In the presence of elevated blood glucose, it potently stimulates the beta cells of the pancreas to secrete insulin (the 'insulinotropic' effect), preparing the body to handle the incoming nutrients.

Explanation:
The hepatic lobule is the basic structural and functional unit of the liver, consisting of plates of hepatocytes radiating from a central vein. Bile canaliculi, sinusoids, and portal triads are key features. Nephrons are kidney units, alveoli lung units, islets pancreatic endocrine units.

Explanation:
Gel electrophoresis, especially agarose gel electrophoresis, separates DNA, RNA, or protein fragments based on size and charge under an electric field. Smaller fragments move faster through the gel matrix. Centrifugation separates by density, chromatography by differential partitioning, spectrophotometry measures light absorption. Electrophoresis is a fundamental tool in molecular biology.