1. In Rh disease of the newborn, maternal antibodies enter fetal circulation and destroy the red blood cells of the fetus. A mother with type O blood has anti-A and anti-B antibodies, but may have a dozen type A children without any problem at all. describe why.

2. Everyone should have a tetanus booster shot every 10 years. That is what we often call a "tetanus shot". Someone who sustains a soil-contaminated injury should also receive a tetanus booster (if none in the past 10 years.) But someone who has symptoms of tetanus should get TIG, tetanus immune globulin. describe the difference, and why TIG is so important.