1. The cell surface molecules that bind specific ligands are know as 2. Treatment with antibiotic drugs that interfere with the intestinal bacteria is sometimes followed by a deficiency of vitamin 3. The act normally called "making a muscle" involves the of the muscle of the 4. While walking in the woods Jack accidentally stepped in a hole and twisted his ankle. Doctor in the emergency room determined that Jack partly tore the ligament connecting his fibula to his calcaneus. This condition is knows as