[Placement Test] ACT Science
Placement Test:
ACT Science
Placement Test:
ACT Science
Figure 2 shows predicted bacteria levels over time in 4 geographic regions with fish populations.
Figure 2 shows predicted bacteria levels over time in 4 geographic regions with fish populations.
Passage II
Certain preservatives known as sulfites are often added to fruit products to keep the fruit fresher longer. Use of sulfites is controversial because studies have linked sulfites to severe reactions in some asthmatics. Students performed 2 experiments to measure sulfite levels.
Experiment 1
Four solutions, each containing a different amount of sulfite dissolved in H2O were prepared. A coloring agent was added that binds with sulfite to form a red compound that strongly absorbs light of a specific wavelength, and each solution was diluted to 100 mL. A blank solution was prepared in the same manner, but no sulfite was added. A colorimeter (a device that measures how much light of a selected wavelength is absorbed by a sample) was used to measure the absorbance of each solution. The absorbances were corrected by subtracting the absorbance of the blank solution from each reading (see Table 1 and Figure 1).
Figure 1
Experiment 2
A 100 g fruit sample was ground in a food processor with 50 mL of H2O and the mixture was filtered. The food processor and remaining fruit were then washed with H2O, these washings were filtered, and the liquid was added to the sample solution. The coloring agent was added and the solution was diluted to 100 mL. The procedure was repeated for several fruits, and the absorbances were measured (see Table 2).
Passage II
Certain preservatives known as sulfites are often added to fruit products to keep the fruit fresher longer. Use of sulfites is controversial because studies have linked sulfites to severe reactions in some asthmatics. Students performed 2 experiments to measure sulfite levels.
Experiment 1
Four solutions, each containing a different amount of sulfite dissolved in H2O were prepared. A coloring agent was added that binds with sulfite to form a red compound that strongly absorbs light of a specific wavelength, and each solution was diluted to 100 mL. A blank solution was prepared in the same manner, but no sulfite was added. A colorimeter (a device that measures how much light of a selected wavelength is absorbed by a sample) was used to measure the absorbance of each solution. The absorbances were corrected by subtracting the absorbance of the blank solution from each reading (see Table 1 and Figure 1).
Figure 1
Experiment 2
A 100 g fruit sample was ground in a food processor with 50 mL of H2O and the mixture was filtered. The food processor and remaining fruit were then washed with H2O, these washings were filtered, and the liquid was added to the sample solution. The coloring agent was added and the solution was diluted to 100 mL. The procedure was repeated for several fruits, and the absorbances were measured (see Table 2).
Passage III
More than 5 percent of Americans have asthma, a chronic disease that affects the airways and lungs, causing shortness of breath, wheezing, and sometimes death. In the United States, rates for asthma have steadily increased, nearly doubling during the past 20 years. There is no cure for asthma. Two researchers discuss factors that cause individuals to develop asthma.
Researcher 1
There has long been an association between the allergen Dermatophagoides pteronyssinus (dust mites) and asthma. Evidence for a causal relationship has been supported by bronchial challenge studies and avoidance experiments. Studies have shown that exposure in the child’s own house was the primary determinant of sensitization. Research from around the world has provided evidence about other indoor allergens, specifically cats, dogs, and the German cockroach. These studies showed that perennial exposure to allergens was an important cause of inflammation in the lungs and associated nonspecific bronchial hyperreactivity. Children are being exposed to more perennial allergens now than ever before. Houses are built more tightly and are better insulated and have more furnishings and fitted carpets. In addition, children are spending more time indoors. This increased exposure to allergens, including dust mites, has led to increased sensitization, and more cases of asthma.
Since assays for total serum IgE (immunoglobulin E) became available, it has been clear that patients with asthma have, on average, higher total IgE than patients with hay fever or no allergy. Recent work on patients hospitalized for asthma has suggested that the interaction between rhinovirus and allergy occurs predominantly among patients with total IgE > 200 IU/ml. Thus, the different properties of allergens could influence both the prevalence and severity of asthma.
Researcher 2
It is widely accepted that air pollution exacerbates asthma. For example, when traffic controls were put in place during the 1996 Summer Olympic Games in Atlanta, Georgia, morning peak traffic counts declined by 23 percent. This in turn lowered ozone (O3) concentrations by 13 percent, carbon monoxide (CO) by 19 percent, and nitrogen dioxide (NO2) by 7 percent. Associated with these declines in ambient air pollution were drops in Medicaid-related emergency room visits and hospitalizations for asthma (down 42 percent), asthma-related care for health maintenance organizations (down 44 percent), and citywide hospitalizations for asthma (down 19 percent). Despite such striking relationships between exposure to air pollution and asthma aggravation, air pollution has not been regarded as a cause of the disease. Increasingly, however, recent studies have been suggesting that air pollution may, indeed, be a cause of asthma.
The Children’s Health Study (CHS) followed 3,535 children with no lifetime history of asthma for five years. During that period, 265 reported a new physician diagnosis of asthma. Analysis of CHS data has shown that children living in communities with high ozone levels developed asthma more often than those in less polluted areas. The hypothesis that ozone might cause asthma is reinforced by a study of 3,091 nonsmoking adults aged 27 to 87 years who were followed for 15 years. The results of this study showed that 3.2 percent of the men and 4.3 percent of the women reported new doctor-diagnosed asthma. The researchers concluded that there was a connection between ozone concentration and development of asthma.
Passage III
More than 5 percent of Americans have asthma, a chronic disease that affects the airways and lungs, causing shortness of breath, wheezing, and sometimes death. In the United States, rates for asthma have steadily increased, nearly doubling during the past 20 years. There is no cure for asthma. Two researchers discuss factors that cause individuals to develop asthma.
Researcher 1
There has long been an association between the allergen Dermatophagoides pteronyssinus (dust mites) and asthma. Evidence for a causal relationship has been supported by bronchial challenge studies and avoidance experiments. Studies have shown that exposure in the child’s own house was the primary determinant of sensitization. Research from around the world has provided evidence about other indoor allergens, specifically cats, dogs, and the German cockroach. These studies showed that perennial exposure to allergens was an important cause of inflammation in the lungs and associated nonspecific bronchial hyperreactivity. Children are being exposed to more perennial allergens now than ever before. Houses are built more tightly and are better insulated and have more furnishings and fitted carpets. In addition, children are spending more time indoors. This increased exposure to allergens, including dust mites, has led to increased sensitization, and more cases of asthma.
Since assays for total serum IgE (immunoglobulin E) became available, it has been clear that patients with asthma have, on average, higher total IgE than patients with hay fever or no allergy. Recent work on patients hospitalized for asthma has suggested that the interaction between rhinovirus and allergy occurs predominantly among patients with total IgE > 200 IU/ml. Thus, the different properties of allergens could influence both the prevalence and severity of asthma.
Researcher 2
It is widely accepted that air pollution exacerbates asthma. For example, when traffic controls were put in place during the 1996 Summer Olympic Games in Atlanta, Georgia, morning peak traffic counts declined by 23 percent. This in turn lowered ozone (O3) concentrations by 13 percent, carbon monoxide (CO) by 19 percent, and nitrogen dioxide (NO2) by 7 percent. Associated with these declines in ambient air pollution were drops in Medicaid-related emergency room visits and hospitalizations for asthma (down 42 percent), asthma-related care for health maintenance organizations (down 44 percent), and citywide hospitalizations for asthma (down 19 percent). Despite such striking relationships between exposure to air pollution and asthma aggravation, air pollution has not been regarded as a cause of the disease. Increasingly, however, recent studies have been suggesting that air pollution may, indeed, be a cause of asthma.
The Children’s Health Study (CHS) followed 3,535 children with no lifetime history of asthma for five years. During that period, 265 reported a new physician diagnosis of asthma. Analysis of CHS data has shown that children living in communities with high ozone levels developed asthma more often than those in less polluted areas. The hypothesis that ozone might cause asthma is reinforced by a study of 3,091 nonsmoking adults aged 27 to 87 years who were followed for 15 years. The results of this study showed that 3.2 percent of the men and 4.3 percent of the women reported new doctor-diagnosed asthma. The researchers concluded that there was a connection between ozone concentration and development of asthma.