Clostridium botulinum is a bacterial organism that can cause disease in people after eating improperly canned foods. As a result of this risk, canning foods involves bringing contents to high pressures and temperatures, thus killing the inactive form of Clostridium, called a spore.

Table 1 shows the ability of a scientist to detect spores as a function of the peak temperature and pressure reached during the process used for canning green beans.

Table 2 shows the infectious dose of spores per cubic millimeter necessary to cause illness in four populations. 

A scientist discovers that, despite adhering to appropriate canning methods as described above, an outbreak of disease due to Clostridium botulinum has taken place in a Minnesota school. She visits the school and collects food samples to determine the cause of the outbreak. While compiling data at the school, she discovers that there are an increasing number of cases of a new strain of Clostridium botulinum. Upon investigation, the scientist finds that all children who attend the school are older than 5 years of age.

A food manufacturer is preparing a canned product that is only approved by the Food and Drug Administration for consumption by children older than 5 years of age. Which of the following is the minimum temperature and pressure needed during their canning process?

Clostridium botulinum is a bacterial organism that can cause disease in people after eating improperly canned foods. As a result of this risk, canning foods involves bringing contents to high pressures and temperatures, thus killing the inactive form of Clostridium, called a spore.

Table 1 shows the ability of a scientist to detect spores as a function of the peak temperature and pressure reached during the process used for canning green beans.

Table 2 shows the infectious dose of spores per cubic millimeter necessary to cause illness in four populations. 

A scientist discovers that, despite adhering to appropriate canning methods as described above, an outbreak of disease due to Clostridium botulinum has taken place in a Minnesota school. She visits the school and collects food samples to determine the cause of the outbreak. While compiling data at the school, she discovers that there are an increasing number of cases of a new strain of Clostridium botulinum. Upon investigation, the scientist finds that all children who attend the school are older than 5 years of age.

Considering the population of the Minnesota school experiencing the Clostridium botulinum outbreak, which of the following would have been most appropriate as a minimum standard for their canning process BEFORE the emergence of the new strain?

Clostridium botulinum is a bacterial organism that can cause disease in people after eating improperly canned foods. As a result of this risk, canning foods involves bringing contents to high pressures and temperatures, thus killing the inactive form of Clostridium, called a spore.

Table 1 shows the ability of a scientist to detect spores as a function of the peak temperature and pressure reached during the process used for canning green beans.

Table 2 shows the infectious dose of spores per cubic millimeter necessary to cause illness in four populations. 

A scientist discovers that, despite adhering to appropriate canning methods as described above, an outbreak of disease due to Clostridium botulinum has taken place in a Minnesota school. She visits the school and collects food samples to determine the cause of the outbreak. While compiling data at the school, she discovers that there are an increasing number of cases of a new strain of Clostridium botulinum. Upon investigation, the scientist finds that all children who attend the school are older than 5 years of age.

Which of the following is the most likely advice that the scientist would give parents of an 11 month old child regarding feeding the child green beans?

Clostridium botulinum is a bacterial organism that can cause disease in people after eating improperly canned foods. As a result of this risk, canning foods involves bringing contents to high pressures and temperatures, thus killing the inactive form of Clostridium, called a spore.

Table 1 shows the ability of a scientist to detect spores as a function of the peak temperature and pressure reached during the process used for canning green beans.

Table 2 shows the infectious dose of spores per cubic millimeter necessary to cause illness in four populations. 

A scientist discovers that, despite adhering to appropriate canning methods as described above, an outbreak of disease due to Clostridium botulinum has taken place in a Minnesota school. She visits the school and collects food samples to determine the cause of the outbreak. While compiling data at the school, she discovers that there are an increasing number of cases of a new strain of Clostridium botulinum. Upon investigation, the scientist finds that all children who attend the school are older than 5 years of age.

According to the data presented, which of the following is the most likely concentration of spores detected in a sample from a canning facility that prepares canned green beans with a peak temperature of 100 C and a peak pressure of 75 PSI?

Understanding the biological features of different bacteria that allow them to grow in unwelcoming environments is necessary to treat and prevent human disease. Modern scientific laboratories, such as those in major hospitals, take blood, urine, and mucus samples from patients and culture them for bacterial growth. During the culturing process, laboratory technicians stain the growing bacteria for a component of their cell wall, the structure that provides shape and rigidity to the bacterium, through a process called Gram staining. Bacteria are typically classified as Gram Positive or Gram Negative, a distinction that is important in selecting the most effective antibiotic for treatment. Gram Positive bacteria appear purple under a microscope, while Gram Negative bacteria appear red. However, some bacteria do not Gram Stain and cannot be seen under a microscope when prepared this way.

Technicians also grow the bacteria on various types of plates containing special growth nutrients to determine which bacteria are causing a specific illness. If a bacterium is able to grow on a selective plate, meaning a plate that contains additional nutrients required for a specific bacterium to grow if it is present in the culture, doctors are able to determine the exact cause of a patient’s illness and prescribe targeted antibiotics to eliminate the infection. Bacteria that commonly cause human illness, their growth requirements, and their appearance on specific growth media are presented below in Table 1.

                                                           Table 1 

Scientists can take the bacteria cultured on the plate and further analyze their enzymes. Three enzymes—urease, catalase, and beta-lactamase—are important for bacterial survival against the human immune system. Urease is responsible for producing urea, a basic molecule that can counteract the bactericidal (bacteria-killing) activity of stomach acid. Catalase, on the other hand, helps bacteria neutralize toxic substances released from human immune cells, allowing them to survive oxidative stress in high-oxygen areas. Finally, beta-lactamase allows Gram Positive bacteria to break down antibiotics called penicillins. While this ability to break down penicillin and its related antibiotic ampicillin was not initially present, bacteria, especially E. coli, have adapted by developing the new enzyme beta-lactamase that opens the ring responsible for penicillin’s bactericidal activity, rending the antibiotic ineffective. This and other examples of antibiotic resistance are becoming more common and are making treatment of serious human diseases very challenging.

A bacterium that stains red in a Gram stain and requires lactose to grow is most likely to cause what disease? 

Understanding the biological features of different bacteria that allow them to grow in unwelcoming environments is necessary to treat and prevent human disease. Modern scientific laboratories, such as those in major hospitals, take blood, urine, and mucus samples from patients and culture them for bacterial growth. During the culturing process, laboratory technicians stain the growing bacteria for a component of their cell wall, the structure that provides shape and rigidity to the bacterium, through a process called Gram staining. Bacteria are typically classified as Gram Positive or Gram Negative, a distinction that is important in selecting the most effective antibiotic for treatment. Gram Positive bacteria appear purple under a microscope, while Gram Negative bacteria appear red. However, some bacteria do not Gram Stain and cannot be seen under a microscope when prepared this way.

Technicians also grow the bacteria on various types of plates containing special growth nutrients to determine which bacteria are causing a specific illness. If a bacterium is able to grow on a selective plate, meaning a plate that contains additional nutrients required for a specific bacterium to grow if it is present in the culture, doctors are able to determine the exact cause of a patient’s illness and prescribe targeted antibiotics to eliminate the infection. Bacteria that commonly cause human illness, their growth requirements, and their appearance on specific growth media are presented below in Table 1.

                                                           Table 1 

Scientists can take the bacteria cultured on the plate and further analyze their enzymes. Three enzymes—urease, catalase, and beta-lactamase—are important for bacterial survival against the human immune system. Urease is responsible for producing urea, a basic molecule that can counteract the bactericidal (bacteria-killing) activity of stomach acid. Catalase, on the other hand, helps bacteria neutralize toxic substances released from human immune cells, allowing them to survive oxidative stress in high-oxygen areas. Finally, beta-lactamase allows Gram Positive bacteria to break down antibiotics called penicillins. While this ability to break down penicillin and its related antibiotic ampicillin was not initially present, bacteria, especially E. coli, have adapted by developing the new enzyme beta-lactamase that opens the ring responsible for penicillin’s bactericidal activity, rending the antibiotic ineffective. This and other examples of antibiotic resistance are becoming more common and are making treatment of serious human diseases very challenging.

A patient with a sinus infection goes to the doctor and a culture of mucus is taken to determine the species of bacteria causing the disease. The technician appropriately selects the Chocolate Agar base but forgets to add Factor X. What effect will this have on the bacterial culture?

Understanding the biological features of different bacteria that allow them to grow in unwelcoming environments is necessary to treat and prevent human disease. Modern scientific laboratories, such as those in major hospitals, take blood, urine, and mucus samples from patients and culture them for bacterial growth. During the culturing process, laboratory technicians stain the growing bacteria for a component of their cell wall, the structure that provides shape and rigidity to the bacterium, through a process called Gram staining. Bacteria are typically classified as Gram Positive or Gram Negative, a distinction that is important in selecting the most effective antibiotic for treatment. Gram Positive bacteria appear purple under a microscope, while Gram Negative bacteria appear red. However, some bacteria do not Gram Stain and cannot be seen under a microscope when prepared this way.

Technicians also grow the bacteria on various types of plates containing special growth nutrients to determine which bacteria are causing a specific illness. If a bacterium is able to grow on a selective plate, meaning a plate that contains additional nutrients required for a specific bacterium to grow if it is present in the culture, doctors are able to determine the exact cause of a patient’s illness and prescribe targeted antibiotics to eliminate the infection. Bacteria that commonly cause human illness, their growth requirements, and their appearance on specific growth media are presented below in Table 1.

                                                           Table 1 

Scientists can take the bacteria cultured on the plate and further analyze their enzymes. Three enzymes—urease, catalase, and beta-lactamase—are important for bacterial survival against the human immune system. Urease is responsible for producing urea, a basic molecule that can counteract the bactericidal (bacteria-killing) activity of stomach acid. Catalase, on the other hand, helps bacteria neutralize toxic substances released from human immune cells, allowing them to survive oxidative stress in high-oxygen areas. Finally, beta-lactamase allows Gram Positive bacteria to break down antibiotics called penicillins. While this ability to break down penicillin and its related antibiotic ampicillin was not initially present, bacteria, especially E. coli, have adapted by developing the new enzyme beta-lactamase that opens the ring responsible for penicillin’s bactericidal activity, rending the antibiotic ineffective. This and other examples of antibiotic resistance are becoming more common and are making treatment of serious human diseases very challenging.

Assume that no laboratory tests are conducted to determine which bacteria are causing patients’ diseases and penicillin is prescribed to all patients. Using information presented in the passage, it could be inferred that the number of days required to treat an infection would do what?

Understanding the biological features of different bacteria that allow them to grow in unwelcoming environments is necessary to treat and prevent human disease. Modern scientific laboratories, such as those in major hospitals, take blood, urine, and mucus samples from patients and culture them for bacterial growth. During the culturing process, laboratory technicians stain the growing bacteria for a component of their cell wall, the structure that provides shape and rigidity to the bacterium, through a process called Gram staining. Bacteria are typically classified as Gram Positive or Gram Negative, a distinction that is important in selecting the most effective antibiotic for treatment. Gram Positive bacteria appear purple under a microscope, while Gram Negative bacteria appear red. However, some bacteria do not Gram Stain and cannot be seen under a microscope when prepared this way.

Technicians also grow the bacteria on various types of plates containing special growth nutrients to determine which bacteria are causing a specific illness. If a bacterium is able to grow on a selective plate, meaning a plate that contains additional nutrients required for a specific bacterium to grow if it is present in the culture, doctors are able to determine the exact cause of a patient’s illness and prescribe targeted antibiotics to eliminate the infection. Bacteria that commonly cause human illness, their growth requirements, and their appearance on specific growth media are presented below in Table 1.

                                                           Table 1 

Scientists can take the bacteria cultured on the plate and further analyze their enzymes. Three enzymes—urease, catalase, and beta-lactamase—are important for bacterial survival against the human immune system. Urease is responsible for producing urea, a basic molecule that can counteract the bactericidal (bacteria-killing) activity of stomach acid. Catalase, on the other hand, helps bacteria neutralize toxic substances released from human immune cells, allowing them to survive oxidative stress in high-oxygen areas. Finally, beta-lactamase allows Gram Positive bacteria to break down antibiotics called penicillins. While this ability to break down penicillin and its related antibiotic ampicillin was not initially present, bacteria, especially E. coli, have adapted by developing the new enzyme beta-lactamase that opens the ring responsible for penicillin’s bactericidal activity, rending the antibiotic ineffective. This and other examples of antibiotic resistance are becoming more common and are making treatment of serious human diseases very challenging.

According to the passage, the bacterium most likely to produce catalase would cause what type of infection?

Understanding the biological features of different bacteria that allow them to grow in unwelcoming environments is necessary to treat and prevent human disease. Modern scientific laboratories, such as those in major hospitals, take blood, urine, and mucus samples from patients and culture them for bacterial growth. During the culturing process, laboratory technicians stain the growing bacteria for a component of their cell wall, the structure that provides shape and rigidity to the bacterium, through a process called Gram staining. Bacteria are typically classified as Gram Positive or Gram Negative, a distinction that is important in selecting the most effective antibiotic for treatment. Gram Positive bacteria appear purple under a microscope, while Gram Negative bacteria appear red. However, some bacteria do not Gram Stain and cannot be seen under a microscope when prepared this way.

Technicians also grow the bacteria on various types of plates containing special growth nutrients to determine which bacteria are causing a specific illness. If a bacterium is able to grow on a selective plate, meaning a plate that contains additional nutrients required for a specific bacterium to grow if it is present in the culture, doctors are able to determine the exact cause of a patient’s illness and prescribe targeted antibiotics to eliminate the infection. Bacteria that commonly cause human illness, their growth requirements, and their appearance on specific growth media are presented below in Table 1.

                                                           Table 1 

Scientists can take the bacteria cultured on the plate and further analyze their enzymes. Three enzymes—urease, catalase, and beta-lactamase—are important for bacterial survival against the human immune system. Urease is responsible for producing urea, a basic molecule that can counteract the bactericidal (bacteria-killing) activity of stomach acid. Catalase, on the other hand, helps bacteria neutralize toxic substances released from human immune cells, allowing them to survive oxidative stress in high-oxygen areas. Finally, beta-lactamase allows Gram Positive bacteria to break down antibiotics called penicillins. While this ability to break down penicillin and its related antibiotic ampicillin was not initially present, bacteria, especially E. coli, have adapted by developing the new enzyme beta-lactamase that opens the ring responsible for penicillin’s bactericidal activity, rending the antibiotic ineffective. This and other examples of antibiotic resistance are becoming more common and are making treatment of serious human diseases very challenging.

A patient with watery diarrhea comes to the doctor after eating spoiled food at a family event. The bacterium most likely responsible for causing the diarrhea would require what growth medium(a)? 

Current high levels of fossil fuel use, including coal-burning power plants and gasoline-powered automobiles, have helped contribute to the high concentrations of sulfur trioxide, SO₃, found in the atmosphere. When sulfur trioxide and water interact, they can undergo the following chemical reaction to produce sulfuric acid, which is the main contributor to acid rain worldwide: 

Acid rain showers are particularly common near coal-burning power plants and large cities. These showers are responsible for significant economic damage to sidewalks, roads, and buildings. Scientists interested in studying the effects of acid rain often use basic substances like calcium carbonate, the main component of limestone buildings, and expose them to varying volumes of acid rain to determine what volume of acid rain is necessary to begin to erode a building. A sample graph of one scientist’s experiment is replicated below:

Measuring acid and base levels is commonly done with a scale called pH, which uses the concentration of hydrogen ions to determine the acidity. Hydrogen ions are in a balance with hydroxide ions to give a scale with a range from 0 to 14. Values equal to or between 0 and 6.9 represent the acidic range where hydrogen ions predominate and values equal to or ranging from 7.1 and 14 represent the basic range where hydroxide ions predominate. Thus, the more hydrogen ions present, the more acidic the solution.

Scientists can tell when a titration (pH) experiment passes a certain pH using compounds called indicators. Indicators are usually colorless at pH levels below that of their specified color change. A table of indicators used by the above scientists and the pH at which they change colors is presented below. 

According to the passage, why are acid rain showers more common near cities?