Problem: Given the background: The Human Immunodeficiency Virus ( HIV ) is the virus that causes Acquired Immunodeficiency Syndrome ( AIDS ). Most researchers believe that the HIV originated in sub-Saharan Africa during the 20th century. HIV is transmitted by sexual contact and by contact with infected bodily fluids, such as blood, semen, breast milk, and vaginal secretions. It is also passed from mother to fetus. HIV is now a pandemic , with an estimated (as of 2008) 38.6 million people now living with the disease worldwide. It is estimated that AIDS has killed more than 25 million people since it was first recognized in 1981. For further information about HIV/AIDS, see the CDC (Centers for Disease Control and Prevention) web site at http://www.cdc.gov/hiv/resources/factsheets/ . and the situation: Dean and Paul both went to volunteered in Africa. They had a blood test when they came back. Paul had been infected with the HIV virus while Dean was healthy and clean. Answer the following question: Which friend has a virus that is transmitted by sexual contact?

A: Paul

Problem: Given the background: Many respiratory diseases are caused by pathogens. A pathogen is an organism that causes disease in another organism. Certain bacteria, viruses, and fungi are pathogens of the respiratory system. The common cold and flu are caused by viruses. The influenza virus that causes the flu is pictured below ( Figure below ). Tuberculosis, whooping cough, and acute bronchitis are caused by bacteria. The pathogens that cause colds, flu, and TB can be passed from person to person by coughing, sneezing, and spitting. Illnesses caused by bacteria can be treated with antibiotics. Those caused by viruses cannot. and the situation: The doctors studied two groups of people, group one which included people with respiratory diseases caused by viruses, and group two, which had people with respiratory diseases caused by bacteria. Answer the following question: Which group didn't include people that had tuberculosis?

A: group one

Problem: Given the background: Animals and some bacteria and fungi carry out lactic acid fermentation. Lactic acid is a waste product of this process. Our muscles perform lactic acid fermentation during strenuous exercise, since oxygen cannot be delivered to the muscles quickly enough. The buildup of lactic acid is believed to make your muscles sore after exercise. Bacteria that produce lactic acid are used to make cheese and yogurt. The lactic acid causes the proteins in milk to thicken. Lactic acid also causes tooth decay, because bacteria use the sugars in your mouth for energy. and the situation: Mark and Jerry are brothers. Mark just got done working out and returned home to find his brother laying down on the couch eating a bag of potato chips. Mark comments that Jerry should really come and work out with him some time. Jerry brushes him aside. Answer the following question: Which person's body has less lactic acid?

A: Jerry

Problem: Given the background: Wilting is the loss of rigidity of non-woody parts of plants. This occurs when the turgor pressure in non-lignified plant cells falls towards zero, as a result of diminished water in the cells. The rate of loss of water from the plant is greater than the absorption of water in the plant. The process of wilting modifies the leaf angle distribution of the plant (or canopy) towards more erectophile conditions. Lower water availability may result from: drought conditions, where the soil moisture drops below conditions most favorable for plant functioning; the temperature falls to the point where the plants vascular system can not function. high salinity, which causes water to diffuse from the plant cells and induce shrinkage; saturated soil conditions, where roots are unable to obtain sufficient oxygen for cellular respiration, and so are unable to transport water into the plant; or bacteria or fungi that clog the plant's vascular system. Wilting diminishes the plant's ability to transpire and grow. Permanent wilting leads to plant death. Symptoms of wilting and blights resemble one another. and the situation: Jim had a small veggie garden that he planted every year. His brother Rob had a similar patch, and he was also a gardener. The plants in Jim's garden started wilting at some point and he found out that his soil had high salinity and some harmful bacteria that wiled the plants indirectly. Rob's plant were ok, because he adjusted the soil's ph with sweet lime. Answer the following question: Which garden soil had lower salinity?

A:
Rob's