1. Parasites survive by leeching essentials like food and nutrients from host organisms. Common parasites include fleas on dogs and dust mites on humans. Parasites of the digestive system can infect humans without them knowing. 2. The most common parasitic infection is the tapeworm, which comes in pork and beef varieties from eating contaminated meat. Tapeworms can grow over 50 feet and live for 20 years without treatment, causing symptoms like nausea and weight loss. Treatment involves medication or UV radiation to kill the tapeworm. 3. Hookworms enter through skin or food/water and migrate to the intestines, causing anemia. Proper sanitation prevents spread. Roundworms