Exam 4: HESI-A2-Reading

Light Pollution I grew up in the city, a place so full of streetlights, spotlights, and searchlights that the sky was never dark enough to see the Milky Way. But last year, I went on a camping trip through the Grand Canyon. When I saw the night sky for the first time, I was in awe. I could not believe how many stars there were. As cities push farther and farther into the wilderness, they create light pollution, the brightening of the night sky by artificial light sources. Light pollution not only hinders our ability to see the beauty of the stars, but it might be causing other problems as well. Light pollution also disrupts the lives of certain animals. For example, too much artificial light can prevent newly-hatched sea turtles from finding the ocean. Owls and other birds that hunt at night can injure themselves by flying into brightly lit buildings. So what is the solution? Obviously, we cannot turn off all of the lights every night. But we can reduce the amount of light we send into the sky. Homeowners should use motion sensors on outdoor lights. Cities should turn off (or at least dim) streetlights after midnight. Businesses and office buildings should turn off their lights when they close for the day. Turning off the lights will help animals and restore the night sky to its former glory. Question: What can be inferred from information found in the passage?

GMOs GMOs, or genetically modified organisms, are organisms whose genes have been altered in laboratories. Scientists modify the genetic codes of plants or animals by inserting copies of desirable genes into the organism's DNA. While modifying organisms in a laboratory is a relatively new scientific development, people have been experimenting with genetics on plants and animals for centuries. For example, cattle ranchers have selectively bred their animals to produce cows that give more milk. Although some people fear the "Frankenstein" nature of GMOs, there is no scientific evidence to suggest that GMO-based foods are harmful for human consumption. In fact, there are several reasons to believe that GMOs are actually quite beneficial. Through genetic modification, scientists can breed species of plants or animals that yield hardier, more abundant, or even more nutritious food. Geneticists have been able to produce rice plants that can survive droughts and wheat plants that are naturally pest-resistant. Some genetically modified foods have been engineered to have higher levels of specific nutrients, such as protein or calcium. Proponents of GMOs argue that these kinds of advances might one day help to end world hunger. Furthermore, genetically modified crops and animals can be bred to require fewer natural resources and produce less waste. This means that GMOs might also be better for the environment. Question: What is the main idea of the passage?

Trans fats Trans fats are unsaturated fats found in many processed foods. Though their prevalence makes them a part of many people's diet, excessive consumption of trans fats can lead to a variety of serious health problems. Certain trans fats are found naturally in some animal products, such as beef and milk. However, the main source of trans fats for many people is processed foods. Partially hydrogenated vegetable oils are trans fats that are often found in shortening, packaged baked goods, and fried foods. Restaurants and food manufacturers often choose to use partially hydrogenated oils because they are less expensive, have longer shelf lives, and require less refrigeration than non-hydrogenated oils. Although trans fats may be less expensive for food manufacturers to use, and thus cheaper for consumers to purchase, excessive intake of these substances can cause significant health risks. Like saturated fat, trans fat raises the level of LDL ("bad") cholesterol in the body. Unlike saturated fat, however, trans fat also lowers the amount of HDL ("good") cholesterol in the body. Therefore, trans fat has a far more negative overall effect on cholesterol levels in the human body than saturated fat. Studies have also linked the consumption of trans fats to increased risk of heart disease, diabetes, obesity, cancer, liver dysfunction, depression, and memory disorders. According to studies, which of these has not been linked to the consumption of trans fats?

Balance Everyone knows that your ears are responsible for your sense of hearing. But did you also know that your ears are also partially responsible for your sense of balance? Your inner ear contains something called the vestibular system, which is a key component in your body's ability to establish and maintain balance. The vestibular system mainly consists of three semicircular canals. Each semicircular canal has a different orientation, allowing them to detect a variety of movements. The canals are filled with a fluid called endolymph. When you move your head, the fluid in the canals also moves; this movement sends signals to the brain about the position of your head. Your brain uses this information to help your body stay balanced. Damage to the vestibular system caused by disease or injury can severely affect a person's balance. Consuming too much alcohol can also temporarily affect the vestibular system. Because alcohol thins the blood, it also changes the viscosity of the endolymph. The thinned-out endolymph sends signals to your brain that your body is rotating even though it is not. This is why many people feel like the room is spinning when they are drunk. Which of these details can be inferred from the text?

Does Low Body Temperature Cause Illness? As children, we are often told to dress warmly in the winter so we do not get sick. This is a common piece of advice, but is there any truth behind it? In fact, there is no scientific evidence to suggest that being cold can get you sick. Most illnesses are caused by viruses and bacteria. Illnesses like strep throat, influenza, and the common cold are only spread through contact with other infected people. How cold you are when you come into contact with the virus or bacteria has nothing to do with whether or not you will get sick. The effect of body temperature on contracting illness was tested on human beings in the 1950s. Researchers divided volunteers into two groups: half of them were kept in a warm room and the other half were kept in a cold room. Both groups were then exposed to rhinovirus-the virus responsible for the common cold. The researchers discovered that members of both groups developed colds at the same rate. Since that first experiment, there have been similar experiments performed with a variety of different illnesses. All have yielded the same result: being cold does not make a person more likely to get sick. Of course, it does seem that people do get sick more often when the weather is cold. However, this is because there is some evidence that people do get sick more often in cold weather, but it has nothing to do with forgetting to bundle up when it is chilly. When it is cold outside, people tend to stay inside. With so many people gathered closely together indoors, germs are spread more easily. Germs are spread from person to person, regardless of how cold or warm their bodies are. What is the author's purpose in writing this passage?

Balance Everyone knows that your ears are responsible for your sense of hearing. But did you also know that your ears are also partially responsible for your sense of balance? Your inner ear contains something called the vestibular system, which is a key component in your body's ability to establish and maintain balance. The vestibular system mainly consists of three semicircular canals. Each semicircular canal has a different orientation, allowing them to detect a variety of movements. The canals are filled with a fluid called endolymph. When you move your head, the fluid in the canals also moves; this movement sends signals to the brain about the position of your head. Your brain uses this information to help your body stay balanced. Damage to the vestibular system caused by disease or injury can severely affect a person's balance. Consuming too much alcohol can also temporarily affect the vestibular system. Because alcohol thins the blood, it also changes the viscosity of the endolymph. The thinned-out endolymph sends signals to your brain that your body is rotating even though it is not. This is why many people feel like the room is spinning when they are drunk. What is the meaning of the word 'viscosity' in paragraph 3?

Does Low Body Temperature Cause Illness? As children, we are often told to dress warmly in the winter so we do not get sick. This is a common piece of advice, but is there any truth behind it? In fact, there is no scientific evidence to suggest that being cold can get you sick. Most illnesses are caused by viruses and bacteria. Illnesses like strep throat, influenza, and the common cold are only spread through contact with other infected people. How cold you are when you come into contact with the virus or bacteria has nothing to do with whether or not you will get sick. The effect of body temperature on contracting illness was tested on human beings in the 1950s. Researchers divided volunteers into two groups: half of them were kept in a warm room and the other half were kept in a cold room. Both groups were then exposed to rhinovirus-the virus responsible for the common cold. The researchers discovered that members of both groups developed colds at the same rate. Since that first experiment, there have been similar experiments performed with a variety of different illnesses. All have yielded the same result: being cold does not make a person more likely to get sick. Of course, it does seem that people do get sick more often when the weather is cold. However, this is because there is some evidence that people do get sick more often in cold weather, but it has nothing to do with forgetting to bundle up when it is chilly. When it is cold outside, people tend to stay inside. With so many people gathered closely together indoors, germs are spread more easily. Germs are spread from person to person, regardless of how cold or warm their bodies are. Based on information in the text, what can be inferred regarding the findings of the experiment described in paragraph 2?

Light Pollution I grew up in the city, a place so full of streetlights, spotlights, and searchlights that the sky was never dark enough to see the Milky Way. But last year, I went on a camping trip through the Grand Canyon. When I saw the night sky for the first time, I was in awe. I could not believe how many stars there were. As cities push farther and farther into the wilderness, they create light pollution, the brightening of the night sky by artificial light sources. Light pollution not only hinders our ability to see the beauty of the stars, but it might be causing other problems as well. Light pollution also disrupts the lives of certain animals. For example, too much artificial light can prevent newly-hatched sea turtles from finding the ocean. Owls and other birds that hunt at night can injure themselves by flying into brightly lit buildings. So what is the solution? Obviously, we cannot turn off all of the lights every night. But we can reduce the amount of light we send into the sky. Homeowners should use motion sensors on outdoor lights. Cities should turn off (or at least dim) streetlights after midnight. Businesses and office buildings should turn off their lights when they close for the day. Turning off the lights will help animals and restore the night sky to its former glory. Question: What is the meaning of the word "hinders" in paragraph 2?

Trans fats Trans fats are unsaturated fats found in many processed foods. Though their prevalence makes them a part of many people's diet, excessive consumption of trans fats can lead to a variety of serious health problems. Certain trans fats are found naturally in some animal products, such as beef and milk. However, the main source of trans fats for many people is processed foods. Partially hydrogenated vegetable oils are trans fats that are often found in shortening, packaged baked goods, and fried foods. Restaurants and food manufacturers often choose to use partially hydrogenated oils because they are less expensive, have longer shelf lives, and require less refrigeration than non-hydrogenated oils. Although trans fats may be less expensive for food manufacturers to use, and thus cheaper for consumers to purchase, excessive intake of these substances can cause significant health risks. Like saturated fat, trans fat raises the level of LDL ("bad") cholesterol in the body. Unlike saturated fat, however, trans fat also lowers the amount of HDL ("good") cholesterol in the body. Therefore, trans fat has a far more negative overall effect on cholesterol levels in the human body than saturated fat. Studies have also linked the consumption of trans fats to increased risk of heart disease, diabetes, obesity, cancer, liver dysfunction, depression, and memory disorders. Which detail is not included as a reason why restaurants use partially hydrogenated oils?

Your Bones At birth, the human body contains over 270 bones. However, as the body grows, some of these bones fuse together. The average adult body contains 206 bones. Together, these bones form the skeleton. The skeleton has many vital functions, including protecting internal organs, providing support, enabling movement, generating blood cells, storing calcium, and helping to regulate the endocrine system. Although we only have one skeleton, it is divided into two major regions: the axial and the appendicular skeletons. The former refers to everything on the body's middle axis, such as the skull, sternum, and vertebrae, while the latter refers to the bones that make up the arms, legs, pelvis, and shoulder girdle. These bones include the femur, the tibia, the ulna, and the radius. Bones are further classified according to their shape and function. The five classifications of bones are: long, short, flat, irregular, and sesamoid bones. Long bones include the fibula and tibia. The carpal bones in the wrist are examples of short bones. Flat bones are thin and curved, and include the ribs, the sternum, and some skull bones. Irregular bones, such as the vertebrae and some facial bones, have complex shapes. Finally, sesamoid bones are small, round bones that form in tendons. There are sesamoid bones in the hands, wrists, and feet, but the most familiar sesamoid bone is the patella, or kneecap. Question: According to the text, what is true regarding irregular bones?

Autism and Vaccines Autism spectrum disorders (ASD) are a range of psychological conditions characterized by challenges with social interaction, behavior, speech, and nonverbal communication. While there is no general consensus among medical professionals about the underlying causes of ASD, theories range from genetic inheritance to environmental factors. One of the most controversial theories to have emerged in recent times is that ASD could be caused by the MMR [mumps, measles, rubella] vaccine that was first developed in the 1960s. The vaccine is a mixture of three live viruses and is administered via injection to children when they are one year old. By the late 1990s, this vaccination had led to the near-eradication of measles in countries that employed widespread inoculation. However, a combination of spurious scientific data and alarmist media attention led to an entirely preventable resurgence in measles cases in the early 21^st century. The first claims of a connection between the MMR vaccine and autism were made in 1998, when an article in The Lancet, a respected British medical journal, reported on eight cases of autism that could possibly be traced back to the administration of an MMR vaccine. An onslaught of media coverage followed the publication of this article. The popular press quickly seized upon this story; in 2002, over 1200 articles were written about the link between MMR vaccines and ASD. Less than 30% of these articles, however, mentioned that an overwhelming amount of scientific evidence suggested that these vaccinations were completely safe. Question: What is the meaning of the word spurious in paragraph two?

The Spread of Yellow Fever Yellow fever is a dangerous disease that is primarily found in tropical climates. Sometimes, people infected with yellow fever suffer only mild flu-like symptoms. In other cases, however, yellow fever can be much more serious, causing kidney problems, liver failure, and sometimes, even death. For many years, people believed that the disease was spread from person to person, much like the cold or flu. However, this was not the case. It took the dedicated research of a doctor named Carlos Juan Finlay to show people how to prevent a disease that was killing people by the thousands. In the 1800's, yellow fever was a serious threat to Cuba's population. Because people believed that the disease was spread from person to person, they tried to prevent the spread of the disease by quarantining people. However, this did not help. Dr) Finlay had a different hypothesis. He noticed the worst outbreaks of yellow fever happened when mosquitoes were most active. This led him to theorize that mosquitoes spread the disease, not people. This was a revolutionary idea; no one had considered the possibility of mosquitoes being vectors of disease. In fact, the idea was so revolutionary that no one believed Finlay for over 20 years. Eventually, Finlay's theory was proven. A team of military doctors led by Dr. Walter Reed conducted a series of experiments that proved once and for all that mosquitoes were indeed responsible for spreading yellow fever. Armed with this information, people took new measures to protect themselves from yellow fever. As a result of this discovery, yellow fever has almost completely disappeared from Cuba and many other nations. Which of the following ideas can be inferred from the text?

Soda Ban Cigarettes. Alcohol. Drugs. Most people agree that these things should be kept away from children and only consumed by adults in limited quantities, if at all. Is the same thing true for soda? A 20-ounce-bottle of soda has over sixteen teaspoons of sugar in it. This is twice the amount of sugar that the American Heart Association recommends a person should eat in an entire day. Furthermore, this 20-ounce bottle of soda delivers over 200 calories and no nutritive value; soda contains no vitamins, minerals, fiber, protein, or other nutrients. Drinking sodas and other sugary beverages can cause serious health problems. Consuming too many of these sugar-filled beverages may increase your risk for developing Type 2 diabetes, obesity, heart disease, tooth decay, and certain kinds of cancer. Studies have also shown that people who drink soda tend to develop a condition known as metabolic syndrome. Metabolic syndrome is a condition characterized by excess abdominal fat, high blood pressure, elevated blood sugar, high levels of triglycerides, and low levels of HDL cholesterol (commonly referred to as "good cholesterol"). Some places have already taken steps to reduce the amount of soda people consume. In California, for example, cafeterias and vending machines in grade schools can not sell soda. The city of Philadelphia also recently added a tax on sugary beverages, making sodas more expensive to purchase. Soda may taste good, but it is terrible for your health. There should be more bans and taxes to keep people from drinking these harmful beverages. What is the meaning of the word 'decay', as in 'tooth decay', found in paragraph 3?

Sports Drinks When you sweat heavily, your body loses electrolytes and water. The most important electrolytes are potassium and sodium-these substances keep your body's cells working properly. Commercials for sports drinks claim that their products will replenish the electrolytes lost during exercise. However, sports drinks are not really necessary for most people. Eating a normal diet that contains healthy amounts of sodium and potassium will maintain the electrolyte balance in your body. Unless you are exercising very intensely for more than 60 minutes, you do not need to use a sports drink to replace lost electrolytes. Most people believe that sports drinks are healthy beverages-after all, if athletes drink them, they must be good for you. On the contrary, sports drinks are filled with artificial ingredients and sugar. One 20-ounce bottle of an average sports drink contains 34 grams of sugar and 130 calories. These empty calories can actually cause you to gain weight instead of helping to keep you fit. One study presented at the 2012 Obesity Society's annual scientific meeting revealed that teenagers gained an average of 3.5 pounds every two years just by consuming a bottle of sports drink every day. The best beverage for you to drink before, during, or after a workout is water. Water has no sugar, no salt, no calories, and no artificial flavors or colors. Water will rehydrate your body and quench your thirst better than any other drink. Unless you are a serious athlete who regularly exercises for more than 60 minutes at a time, sports drinks ultimately do more harm than good. Question: Which of the following is a way to maintain the electrolyte balance in one's body?

The Spread of Yellow Fever Yellow fever is a dangerous disease that is primarily found in tropical climates. Sometimes, people infected with yellow fever suffer only mild flu-like symptoms. In other cases, however, yellow fever can be much more serious, causing kidney problems, liver failure, and sometimes, even death. For many years, people believed that the disease was spread from person to person, much like the cold or flu. However, this was not the case. It took the dedicated research of a doctor named Carlos Juan Finlay to show people how to prevent a disease that was killing people by the thousands. In the 1800's, yellow fever was a serious threat to Cuba's population. Because people believed that the disease was spread from person to person, they tried to prevent the spread of the disease by quarantining people. However, this did not help. Dr) Finlay had a different hypothesis. He noticed the worst outbreaks of yellow fever happened when mosquitoes were most active. This led him to theorize that mosquitoes spread the disease, not people. This was a revolutionary idea; no one had considered the possibility of mosquitoes being vectors of disease. In fact, the idea was so revolutionary that no one believed Finlay for over 20 years. Eventually, Finlay's theory was proven. A team of military doctors led by Dr. Walter Reed conducted a series of experiments that proved once and for all that mosquitoes were indeed responsible for spreading yellow fever. Armed with this information, people took new measures to protect themselves from yellow fever. As a result of this discovery, yellow fever has almost completely disappeared from Cuba and many other nations. What is the best summary of this passage?

Carbon Monoxide Poisoning Carbon monoxide (CO) is a poisonous gas that has is odorless, colorless, and tasteless. These qualities make it possible for you to breathe in toxic amounts of carbon monoxide without realizing that you are in danger. Carbon monoxide is produced when materials that contain carbon, such as wood, coal, gasoline, oil, or natural gas, are burned. If the space where the materials are burned is not ventilated properly, then the carbon monoxide that is released can build to dangerous levels. Inhaling carbon monoxide causes the gas to build up in your bloodstream. CO molecules displace oxygen in your blood, depriving your heart, brain, and other organs of oxygen. Early signs of carbon monoxide poisoning include flu-like symptoms, such as dizziness, drowsiness, headache, blurred vision, nausea, and vomiting. Prolonged exposure to large amounts of CO can lead to unconsciousness, irreversible heart, lung, or brain damage, and death. People who are most at risk of carbon monoxide poisoning include pregnant women, young children, the elderly, and people with serious heart or lung conditions. To prevent carbon monoxide poisoning, people should make sure that places where carbon-containing materials are burned are properly ventilated. Carbon monoxide detectors should also be present in homes, garages, and workspaces. What is the best summary for the passage?

Lyme Disease Lyme disease is caused by ticks. More specifically, Lyme disease is caused by Borrellia bacteria, which are carried by ticks. When ticks infected with this bacteria bite humans, the bacteria can be transmitted into the bloodstream, causing an illness known as Lyme disease. The symptoms of Lyme disease include fever, headache, fatigue, and joint and muscle pain. One of the most noticeable signs is a rash that looks like a series of red rings radiating out from the bite. This usually appears a week after the tick bite. However, not everyone with Lyme disease gets this rash. The good news is that Lyme disease can be treated with antibiotics. Most people recover quickly and fully. However, if Lyme disease is not treated properly, patients can suffer from debilitating symptoms weeks, months, and even years after the bite. This condition is known as post-treatment Lyme disease (PTLD) or chronic Lyme disease (CLD). To protect yourself from Lyme disease, always cover your skin with clothing or insect repellent when hiking or camping. If you get bitten by a tick, remove the tick right away; most cases of Lyme disease require the tick to be attached for 36 to 48 hours. If red rings appear, see a doctor right away. Lyme disease can be harmful, but it is preventable and treatable with early intervention. Question: Why would the author include the detail "most cases of Lyme disease require the tick to be attached for 36 to 48 hours" in paragraph 4?

During the 18th century, toll roads began appearing all over England, spreading from London all the way to Scotland. But these roads were made of small stones piled on top of mud, so even a light rain could render them impassable. A blind engineer named John Metcalf came up with a solution. He insisted that roads have a strong stone foundation. He "crowned" the roads too, meaning that he made them higher in the middle than on the sides. He added a ditch on either side, providing proper drainage to keep the roadways from caving in due to excess moisture. This also prevented potholes. But his methods proved costly and many local governments were loath to pay the construction costs. Undeterred, Metcalf challenged a colonel to race him to London. Thanks to the lousy road conditions, he made it to the city on foot faster than the colonel could get there in his horse-drawn buggy. As a result, towns across England began adopting Metcalf's engineering ideas. Even today, many of these ideas are still in use not only in England but around the world. What is the main idea of the passage?

Whether we like it or not, global climate change will have pronounced effects on the world we live in. Oddly enough, climate change brings with it some minor positive effects. For instance, the frost-free growing season will lengthen. This means that farmers will have a longer period of time in which to grow crops. Ultimately, some farmers may be able to plant and harvest two crops per year, rather than just one. But for every positive effect, there are ten negative ones. Temperatures will continue to rise. Of course, this could spell the doom for polar ice caps. Climate change also brings with it changes in precipitation patterns. More precipitation is expected for the northern U.S., while much less is expected for the Southwest. But perhaps more than anything else, climate change could devastate our coastal cities. Experts estimate that sea levels will rise one to four feet within the next sixty years. So, while not all of the results of climate change are negative, we clearly stand to lose more than we gain. What is the main idea of the passage?

Vaping Electronic cigarettes, or e-cigarettes, are electronic devices that provide users with the same nicotine "fix" that they would receive from a traditional cigarette. However, e-cigarettes do not burn tobacco, and thus do not produce the same toxic chemicals as traditional cigarettes. For this reason, many believe that using e-cigarettes (also known as "vaping") is a safe alternative to smoking tobacco. This perception has turned vaping into a billion-dollar industry and has made vaping extremely popular, especially among adolescents. However, even though e-cigarettes do not produce tobacco smoke, they are still not completely safe. E-cigarette vapor contains a variety of toxic chemicals, including formaldehyde and acetaldehyde. Although they are harmless in small amounts, there have not been any studies of the dangers of long-term exposure to these chemicals. Furthermore, the nicotine in e-cigarettes is just as addictive as the nicotine in traditional cigarettes. Withdrawal symptoms from nicotine deprivation include mood swings, anxiety, and changes in appetite. Exposure to nicotine can also be dangerous for people with cardiovascular problems. While vaping may be better for you than smoking traditional cigarettes, more research needs to be done before e-cigarettes can be considered completely safe. People-especially adolescents-should be wary of getting hooked on these "harmless" cigarettes. Question: Which of these is mentioned in the text as having contributed to the perception that e-cigarettes are a safe alternative to traditional cigarettes?