Consider the following statements about proteins: 1. They are made of amino acids. 2. Peptide bonds link amino acids. 3. Hemoglobin is a transport protein. Which of the above is/are correct? MCQ with Answer and Explanation

Explanation:
The spleen is the largest lymphoid organ in the body. It is located in the abdominal cavity, specifically in the upper left quadrant, tucked between the stomach and the diaphragm, protected by the rib cage (ribs 9-11). It functions primarily in filtering blood, removing old or damaged red blood cells, storing platelets, and mounting immune responses against blood-borne pathogens. It is not located in the thoracic, pelvic, or cranial cavities.

Explanation:
Glucagon, secreted by alpha cells of the pancreas when blood glucose is low, binds to liver receptors activating glycogenolysis (glycogen → glucose) and gluconeogenesis. Insulin promotes glycogenesis (glucose → glycogen). Thyroxine affects metabolism, somatostatin inhibits both insulin and glucagon.

Explanation:
Root pressure is the positive hydrostatic pressure developing in the xylem of roots due to active transport of ions into the vascular cylinder, drawing water osmotically. It can cause guttation in some plants. Transpiration pull is the main driving force for water ascent. Turgor pressure is the pressure of cell contents against the cell wall.