Problem: Given the background: The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow moving water of pools. These distinctions form the basis for the division of rivers into upland and lowland rivers. The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients. Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species. A dam produces negative effects that continue down the watershed. The most important negative effects are the reduction of spring flooding, which damages wetlands, and the retention of sediment, which leads to loss of deltaic wetlands. and the situation: Jill lives out in a peaceful quiet area with hardly any other people around. Next to her home is a calm peaceful river. The river doesn't have an official name that she is aware of, but her family has always called it River Treetop due to the large tree next to it. Also next to her house, there is a roaring river that runs for miles. The river is so loud that it can be hard to hear yourself think sometimes if you are sitting next to it. For this reason, Jill has always referred to the river as River Chaos. Answer the following question: Which body of water is less concentrated with dissolved oxygen?

A: River Treetop

Problem: Given the background: Any unused energy in food, whether it comes from carbohydrates, proteins, or lipids, is stored in the body as fat. An extra 3,500 Calories of energy results in the storage of almost half a kilogram (1 pound) of stored body fat. People who consistently consume more food energy then they need may become obese. Obesity occurs when the body mass index is 30.0 kg/m 2 or greater. Body mass index (BMI) is an estimate of the fat content of the body. It is calculated by dividing a person's weight (in kilograms) by the square of the person's height (in meters). Obesity increases the risk of health problems such as type 2 diabetes and hypertension. and the situation: Two groups of people were part of a nutrition study. Group O was made up of individuals that consumed an extra 2000 calories per day, while group B had a normal daily caloric consumption. Answer the following question: Which group had more people with elevated BMI?

A: Group O

Problem: Given the background: The Fink effect, also known as "diffusion anoxia",[1] "diffusion hypoxia",[2] or the "third gas effect",[3] is a factor that influences the pO2 (partial pressure of oxygen) within the alveolus. When water-insoluble gases such as anesthetic agent N2O (nitrous oxide) are breathed in large quantities they can be dissolved in body fluids rapidly. This leads to a temporary increase in both the concentrations and partial pressures of oxygen and carbon dioxide in the alveolus. and the situation: An accident occurred in a local chemical factory. Consequently, large amount of various gases been released to the atmosphere. Local hospital is evaluating all the patients who have been affected by this accident. John, a doctor at the hospital, is seeing two patients, patient A and patient B. He concluded that patient A was having Fink effect. But he didn't see any sign of Fink effect in patient B. Answer the following question: Which patient would have breathed normal quantities of water-insoluble gases, patien A or patient B?

A: patient B

Problem: Given the background: Ionizing radiation has many practical uses in medicine, research and construction, but presents a health hazard if used improperly. Exposure to radiation causes damage to living tissue; high doses result in Acute radiation syndrome (ARS), with skin burns, hair loss, internal organ failure and death, while any dose may result in an increased chance of cancer and genetic damage; a particular form of cancer, thyroid cancer, often occurs when nuclear weapons and reactors are the radiation source because of the biological proclivities of the radioactive iodine fission product, iodine-131. However, calculating the exact risk and chance of cancer forming in cells caused by ionizing radiation is still not well understood and currently estimates are loosely determined by population based data from the atomic bombings of Hiroshima and Nagasaki and from follow-up of reactor accidents, such as the Chernobyl disaster. The International Commission on Radiological Protection states that "The Commission is aware of uncertainties and lack of precision of the models and parameter values", "Collective effective dose is not intended as a tool for epidemiological risk assessment, and it is inappropriate to use it in risk projections" and "in particular, the calculation of the number of cancer deaths based on collective effective doses from trivial individual doses should be avoided." and the situation: Tom and Jerry are two friends who have always had competitions with one another throughout their whole lives. Yesterday, they just finished their most unique competition so far. Each man was given a room to sit in that had several highly radioactive objects in it. The challenge was to see who would stay in the chamber longer. Tom didn't stay in his room for very long, but Jerry felt determined to win and stayed in his chamber almost the entire day. Answer the following question: Will Tom or Jerry be more likely to be getting cancer treatment two years from now?

A:
Jerry