Answer to Question 1
Diffusion is the passage of dissolved particles or solute from a more concentrated to a more dilute solution; osmosis is the movement of water molecules from a dilute to a more concentrated solution.
Answer to Question 2
1 . Immediate hypersensitivity. Localized response: hay fever, food allergy; systemic response: bee sting, penicillin anaphylaxis
2 . Cytotoxic hypersensitivity reactions. Blood transfusion reactions, Rh hemolytic disease, autoimmune hemolytic anemia
3 . Immune complex disease. Some types of glomerulonephritis; lupus erythematosus; rheumatoid arthritis
4 . Delayed (cell-mediated) hypersensitivity. Tuberculosis; fungus and parasitic infections; contact dermatitis