Question: Given the 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. and the situation: Two brothers went to the doctor's office for a medical exam and blood tests. Dan found out he is healthy and had normal blood cholesterol and calcium levels. Ben however, was told that he had a disease called hypercalcaemia and had to start a treatment for that. Answer the following question: Which brother didn't have excess calcium salts deposited in the heart?
Answer: Dan

Question: Given the background: Sand mining is a direct cause of erosion, and impacts the local wildlife.[2] Various animals depend on sandy beaches for nesting clutches, and mining has led to the near extinction of gharials (a species of crocodile) in India. Disturbance of underwater and coastal sand causes turbidity in the water, which is harmful for organisms like coral that need sunlight. It can also destroy fisheries, financially harming their operators. Removal of physical coastal barriers, such as dunes, sometimes leads to flooding of beachside communities, and the destruction of picturesque beaches causes tourism to dissipate. Sand mining is regulated by law in many places, but is often done illegally.[3] Globally, it is a $70 billion industry, with sand selling at up to $90 per cubic yard.[4] and the situation: Twenty first century is seeing an explosion of artificial island building. Many countries are building islands in the middle of seas and oceans, which they often use for tourism or for defensive purposes. For example, UAE had build several islands in the Persian Gulf. To build those islands they had to ask Oman and Qatar to export sand to them. Qatar declined to export sand, but Oman agreed. Oman in turn had to mine huge quantity of sand in their own country. Answer the following question: In which country coral reef would deteriorate, Qatar or Oman?
Answer: Oman

Question: Given the background: An equilibrium can also be disrupted by the full or partial removal of a reactant or product. If the concentration of a substance is decreased, the system will respond by favoring the reaction that replaces that substance. In the industrial Haber-Bosch process, NH 3 is removed from the equilibrium system as the reaction proceeds. As a result, the forward reaction is favored so that more NH 3 will be produced. The concentrations of N 2 and H 2 decrease. Continued removal of NH 3 will eventually force the reaction to go to completion until all of the reactants are used up. If either N 2 or H 2 were removed from the equilibrium system, the reverse reaction would be favored, and the concentration of NH 3 would decrease. and the situation: Jennifer and Justin are examining the principle of chemical equilibrium in their second year organic chemistry course. They are performing a reaction that involves hydrogen gas and glucose as the starting reactants, and the products formed in the reaction are carbon dioxide and oxygen gas. Jennifer and Justin add the materials, and then wait until the reaction has reached equilibrium. Afterwards, Jennifer removes glucose from her reaction mixture, while Justin removes carbon dioxide from his reaction mixture. Answer the following question: Which person's reaction, Jennifer's or Justin's, will begin producing more carbon dioxide?
Answer:
Justin's