Answer to Question 1
Hepatitis is an inflammation of the liver caused by a virus, bacteria, toxins, obstruction, parasites, or chemicals. Hepatitis A is generally transmitted via the oral-fecal route. Sources of contamination include drinking water, food, and sewage. Symptoms are typically nausea, vomiting and fatigue. There are no special treatments for hepatitis A except rest, adequate nutrition, and fluids. Hepatitis B (HBV) is transmitted through transfusions of blood or through improperly sterilized medical instruments or other skin-puncturing instruments that have come in contact with contaminated blood. Acute hepatitis B virus infection is a short-term illness, much like HAV infection. Chronic hepatitis B may cause cirrhosis or liver cancer. For acute infection, no medication is available; treatment is supportive, much like that for HAV. For chronic infection, two oral medications, tenofovir and entecavir, and an injected drug, pegylated interferon, are considered first-line options. Hepatitis C (HCV) transmission occurs when an individual is exposed to blood or body fluids from an infected person. Hepatitis C is often asymptomatic but may cause jaundice, abdominal pain, dark urine, and fatigue. The therapy for chronic hepatitis C has become more effective over the 10 years since alpha interferon was first approved for use. Recently, a new oral, non-interferon medication, sofosbuvir, was approved by the FDA for the treatment of chronic hepatitis C.
Answer to Question 2
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Four main models that describe the relationship between ecosystem function and biodiversity.
Posterior views of H. erectus, Neandertal, and modern H. sapiens show differences in vault shape.
Use of squid giant axons for studies of neural transmission
Active transport: Absorption Methods in the Small Intestine
Common Methods of Contraception
Major phenotypic differences between maize and teosinte