Background: Excess intake of calcium may cause hypercalcaemia. However, because calcium is absorbed rather inefficiently by the intestines, high serum calcium is more likely caused by excessive secretion of parathyroid hormone (PTH) or possibly by excessive intake of vitamin D, both which facilitate calcium absorption. It may also be due to bone destruction that occurs when tumours metastasize within bone. All these conditions result in excess calcium salts being deposited in the heart, blood vessels, or kidneys. Symptoms include anorexia, nausea, vomiting, memory loss, confusion, muscle weakness, increased urination, dehydration, and metabolic bone disease. Chronic hypercalcaemia typically leads to calcification of soft tissue and its serious consequences: for example, calcification can cause loss of elasticity of vascular walls and disruption of laminar blood flowand thence to plaque rupture and thrombosis. Conversely, inadequate calcium or vitamin D intakes may result in hypocalcaemia, often caused also by inadequate secretion of parathyroid hormone or defective PTH receptors in cells. Symptoms include neuromuscular excitability, which potentially causes tetany and disruption of conductivity in cardiac tissue. Paragraph: Two friends went to the doctor because they weren't feeling well. As it turns out Danny had a condition called hypercalcaemia, while Greg had hypocalcaemia. Given the paragraph above, please answer correctly the following question: Which friend had an excessive intake of vitamin D?
Ans: Danny

Background: Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure below ). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Paragraph: Two neighboring towns used different approaches to agriculture. Big town used pesticides and fertilizers, while Small town applied permaculture principles and organic farming methods. Given the paragraph above, please answer correctly the following question: Which town had more growth of water plants because of fertilizer?
Ans: Big

Background: Soon after the original study was published, other researchers tried to replicate the research. However, it could not be replicated. No other studies could find a link between the vaccine and autism. As a result, scientists became convinced that the original results were incorrect. Eventually, investigators determined that the original study was a fraud. They learned that its author had received a large amount of money to find evidence that the vaccine causes autism, so he faked his research results. If other scientists had not tried to replicate the research, the truth might never have come out. You can read more about this case at the URL below. Paragraph: John works for the NSF. He has two research proposals in front of him, case A and case B. Both are looking for further funding. Case A research has been replicated by other researchers, but case B research could not be replicated by others. He needs to decide which research should get further funding. Given the paragraph above, please answer correctly the following question: In which case the original results were most likely incorrect, case A or case B?
Ans: case B

Background: In nature, when the population size is small, there is usually plenty of food and other resources for each individual. When there is plenty of food and other resources, organisms can easily reproduce, so the birth rate is high. As the population increases, the food supply, or the supply of another necessary resource, may decrease. When necessary resources, such as food, decrease, some individuals will die. Overall, the population cannot reproduce at the same rate, so the birth rates drop. This will cause the population growth rate to decrease. Paragraph: John is studying a species in two similar countries, country A and country B. Country A has large population, but country B has small population of that species. John is pondering about how this species would fare in the future in these two countries. Given the paragraph above, please answer correctly the following question: In which country the growth rate of the species would be lower, country A or country B?
Ans: country A