Problem: You are given a new situation: Two brothers went to the doctor for their yearly examination. Liam found out he has high cholesterol, while Rudy found out his triglycerides and cholesterol are within normal parameters.  and a hint : Cholesterol has been implicated in heart disease for decades. Atherosclerosis is a disorder of the arteries in which cholesterol and other materials are deposited on the interior of the arterial wall. These deposits lead to the formation of plaques that can restrict or even block the flow of blood through these blood vessels (see Figure below ). A decrease in the flow of blood can lead to high blood pressure and a lowered oxygen supply to the heart muscle. A complete blockage of blood flow to parts of the heart (a heart attack) can cause significant damage due to oxygen deprivation, in some cases leading to death.  Please answer this question : Which brother was less at risk for atherosclerosis?

A: Rudy


Problem: You are given a new situation: Xuejiang, a town in China, recently increased their levels of steel and construction materials production. The factories that produce these materials have been burning high levels of fossil fuels to support this production.  Ontario, meanwhile, has been burning low levels of fossil fuels thanks to investment in alternative energies, and a general decrease in the manufacturing industries there.  and a hint : When humans dig up and use fossil fuels, we have an impact on the carbon cycle ( Figure below ). This carbon is not recycled until it is used by humans. The burning of fossil fuels releases more carbon dioxide into the atmosphere than is used by photosynthesis. So, there is more carbon dioxide entering the atmosphere than is coming out of it. Carbon dioxide is known as a greenhouse gas , since it lets in light energy but does not let heat escape, much like the panes of a greenhouse. The increase of greenhouse gasses in the atmosphere is contributing to a global rise in Earth’s temperature, known as global warming or global climate change.  Please answer this question : Which area will release more carbon dioxide, Xuejiang or Ontario?

A: Xuejiang


Problem: You are given a new situation: Gary, a high school student, is supposed to be studying two different cells under a microscope during his biology class. Gary doesn't like biology class at all though and can't find the motivation to look at the cells in detail. In his homework where students are supposed to write what they observed, Gary simply wrote down the first thing he saw under the microscope which was that Cell A is larger than cell B. It won't get him a great grade, but Gary is hoping it will at least get him a pass on the assignment.  and a hint : As a cell grows, its volume increases more quickly than its surface area. If a cell was to get very large, the small surface area would not allow enough nutrients to enter the cell quickly enough for the cell’s needs. This idea is explained in Figure below . However, large cells have a way of dealing with some size challenges. Big cells, such as some white blood cells, often grow more nuclei so that they can supply enough proteins and RNA for the cell’s requirements. Large, metabolically active cells often have lots of cell protrusions, resulting in many folds throughout the membrane. These folds increase the surface area available for transport of materials into or out of the cell. Such cell types are found lining your small intestine, where they absorb nutrients from your food through protrusions called microvilli .  Please answer this question : Which cell has less volume?

A: cell B


Problem: You are given a new situation: Two rivers spring from the same mountain. Olt was a fast moving river, while Mures river was slow moving and deep. Both rivers are very important for the local economies.  and a hint : 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.  Please answer this question : Which river had a water that contains lower concentrations of dissolved oxygen?

A:
Mures