Assertion (A): Water is essential for photosynthesis. Reason (R): Water is split to release oxygen, and its hydrogen is used to reduce CO₂. MCQ with Answer and Explanation

Explanation:
Erythropoietin (EPO), mainly from kidneys, promotes erythropoiesis in bone marrow. Thrombopoietin stimulates platelets, interleukins are immune cytokines, CSFs for white blood cells. EPO is used to treat anemia.

Explanation:
Diapedesis (extravasation) is the migration of leukocytes through the endothelial junctions of capillaries into tissues in response to inflammation. Chemotaxis is the directed movement along a chemical gradient, phagocytosis is ingestion, opsonization is coating for phagocytosis. Both diapedesis and chemotaxis are part of the inflammatory response.

Explanation:
Lysosomes are membrane-bound vesicles containing hydrolytic enzymes formed by the Golgi apparatus. The Golgi modifies, sorts, and packages proteins from the rough ER into vesicles; some become lysosomes. These organelles function in intracellular digestion and autophagy. Rough ER synthesizes enzymes, but the final packaging into lysosomes occurs at the Golgi. Hence, Golgi is sometimes called the 'traffic police' of the cell.