Problem: I read this background article the other day: Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen . Carcinogens may be pathogens, chemicals, or radiation. I am facing a new situation today: A team of scientists studied two groups of mice. Group C was exposed to carcinogens, while group N was not. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which group of mice had fewer abnormal cells divide uncontrollably?

A: group N

Problem: I read this background article the other day: Beginning in September 2012, the U.S. Food and Drug Administration will require larger, more prominent cigarette health warnings on all cigarette packaging and advertisements in the United States. These warnings are a significant advancement in communicating the dangers of smoking. These new cigarette health warnings contains nine different warnings that will increase awareness of the specific health risks associated with smoking, such as death, addiction, lung disease, cancer, stroke and heart disease. These warnings include: I am facing a new situation today: David collects cigarette packs of different years. He found that two of his packs, pack A and pack B, are very different. Pack A is from before September 2012, and pack B is from after September 2012. He started searching on the internet to find out why the packs were different. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Would pack A induce less or more awareness of smoking health risks than pack B?

A: less

Problem: I read this background article the other day: In slippery conditions some riders prefer to ride fixed because they believe the transmission provides increased feedback on back tire grip. However, there is also an increased risk of loss of control in such conditions. This is especially so when taking into account the large number of riders who ride brakeless. These riders must brake entirely through the drivetrain. Ideally this is done by resisting the forward motion of the pedals, shedding speed while the bike is still moving. Alternatively, though far less efficiently, one can brake by stopping the motion of the pedals in mid-rotation, causing the rear wheel to lock in place, allowing the bicycle to skid and slow down from kinetic friction (see below).[22] Descending any significant gradient is more difficult as the rider must spin the cranks at high speed (sometimes at 170 rpm or more), or use the brakes to slow down. Some consider that the enforced fast spin when descending increases suppleness or flexibility, which is said to improve pedalling performance on any type of bicycle; however the performance boost is negligible compared to the benefits of riding a free wheel.[23] I am facing a new situation today: Two villages are inhabited by lots of people that ride bicycles. Hill village is located on a mountain and gets lots of rain, and Low village is situated in a valley, and has more sunny days. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which village has more cyclists going downhill?

A: Hill

Problem: I read this background article the other day: The theory of evolution by natural selection was proposed at about the same time by both Charles Darwin and Alfred Russel Wallace, shown in Figure below , and was set out in detail in Darwin's 1859 book On the Origin of Species . Natural selection is a process that causes heritable traits that are helpful for survival and reproduction to become more common, and harmful traits, or traits that are not helpful or advantageous for survival to become more rare in a population of organisms. This occurs because organisms with advantageous traits are more "fit" to survive in a particular environment and have "adapted" to the conditions of that environment. These individuals will have greater reproductive success than organisms less fit for survival in the environment. This will lead to an increase in the number of organisms with the advantageous trait(s) over time. Over many generations, adaptations occur through a combination of successive, small, random changes in traits, and natural selection of those variants best-suited for their environment. Natural selection is one of the cornerstones of modern biology. I am facing a new situation today: In sub-Saharan Africa there are two predominant groups of antelope present. The first group of antelope, group A, have long necks and strong teeth. The second group of antelope, group B, have shorter necks and weaker teeth. Because of their longer necks and stronger teeth, the antelope from group A are more easily able to pick fruit and leaves from the tall trees in the region compared to antelope from group B. Using the knowledge I acquired from the background article, how should I answer correctly the following question regarding my new situation: Which group of antelope is more adapted to the environment?

A:
group A