Q1. A. What might be the rationale behind using multidrug therapy instead of single drug therapy? B. What would happen to the virus population if multiple drugs are given to a patient in a sequence (not simultaneously) over course of few months? C. What would occur to the virus population, if multiple drugs are given simultaneously? D. What would occur to the viral population if the patient is taken off the drugs for a while as a method of helping the patient to cope with side effects of the drugs?

Q2. Their water vascular system with tube feet is unique. Sea lilies (Crinoids) might be closest to the ancestral echinoderm. Other groups are modified from this. Chordates -An interesting sidelight: Which side is up?