1. Water supplies are treated with chlorine to kill pathogens. Chlorine reacts well with many other chemicals because it is a strong oxidant. What does this mean? Answer: Option 4 Because chlorine is strongly electronegative and needs one electron to fill its outer shell, it strongly pulls electrons from other substances. Explanation: Chlorine is known to be one of the most electronegative atoms of the periodic table ( with a value of approx 3 in the pauling scale). This means that it has a very strong tendancy to attract electron. Also Chlorine (Atomic number 17, configuration of electrons 2, 8, 7) has seven electrons in the valence shell so it needs one electron to fill its outer shell . 2. Tests to monitor water safety often report the number of fecal coliform bacteria found in samples. Which of the following statements accurately reflects water safety recommendations based upon fecal coliform levels? Answer : Here by mistake the first two options are exactly same, one of them probably needs to be corrected to If the level of fecal coliform bacteria is low, then the water is safe for drinking and recreational purposes. This option will be the correct option. Explanation: Fecal coliforms are bacteria which indicate that the water might have been exposed to fecal matter. They are an excellant proxy to make sure that the water doesn\'t contain any human pathogens. So if the Fecal coliforms count is low it indicates that the chances of water containing any human pathogen is also low and therefore it can be used for drinking and recreational purposes 3. When an individual has severe diarrhea, as can occur with cholera, rehydration solution with glucose, salt, sodium bicarbonate, and potassium chloride can be administered. Why is it important to use a solution like this rather than simply giving the individual water? Answer: Option 1: Diarrhea causes the loss of electrolytes, not just fluids, and it is important to replace the electrolytes as well. Glucose is transported into intestinal epithelial cells, along with sodium, by symporters. It is included as well because glucose is not sufficiently absorbed while sodium is lacking. Explanation: The answer is self explanatory 4.Vibrio cholerae is a human pathogen that causes cholera. It has an unusual shape distinctive of its genus. Considering that it does not have one of the most common bacterial shapes, what is the shape of this species? Answer Option 2 - Curved rod Explanation:Vibrio\'s unique curved rod shape is also called the \"comma\" shape. Just helps to remember it more easily 5. Legionella pneumophilia can grow in water and is transmitted in aerosols. Which of these has an infection NOT been linked to? Answer option 4 -ocean water 6. On a global scale, the most important waterborne bacterial pathogens are __________. Answer Option 4 -Vibrio cholerae and Salmonella enterica serovar Typhi 7. Food that is heavily salted or candied does not need to be refrigerated. Why not? Answer option 2 -E.

1. 1. Water supplies are treated with chlorine to kill pathogens. Chlorine reacts well with many
other chemicals because it is a strong oxidant. What does this mean?
Answer: Option 4 Because chlorine is strongly electronegative and needs one electron to fill its
outer shell, it strongly pulls electrons from other substances.
Explanation: Chlorine is known to be one of the most electronegative atoms of the periodic table
( with a value of approx 3 in the pauling scale). This means that it has a very strong tendancy to
attract electron. Also Chlorine (Atomic number 17, configuration of electrons 2, 8, 7) has seven
electrons in the valence shell so it needs one electron to fill its outer shell .
2. Tests to monitor water safety often report the number of fecal coliform bacteria found in
samples. Which of the following statements accurately reflects water safety recommendations
based upon fecal coliform levels?
Answer : Here by mistake the first two options are exactly same, one of them probably needs to
be corrected to
If the level of fecal coliform bacteria is low, then the water is safe for drinking and recreational
purposes.
This option will be the correct option.
Explanation: Fecal coliforms are bacteria which indicate that the water might have been exposed
to fecal matter. They are an excellant proxy to make sure that the water doesn't contain any
human pathogens. So if the Fecal coliforms count is low it indicates that the chances of water
containing any human pathogen is also low and therefore it can be used for drinking and
recreational purposes
3. When an individual has severe diarrhea, as can occur with cholera, rehydration solution with
glucose, salt, sodium bicarbonate, and potassium chloride can be administered. Why is it
important to use a solution like this rather than simply giving the individual water?
Answer: Option 1: Diarrhea causes the loss of electrolytes, not just fluids, and it is important to
replace the electrolytes as well. Glucose is transported into intestinal epithelial cells, along with
sodium, by symporters. It is included as well because glucose is not sufficiently absorbed while
sodium is lacking.
Explanation: The answer is self explanatory
4.Vibrio cholerae is a human pathogen that causes cholera. It has an unusual shape distinctive of
its genus. Considering that it does not have one of the most common bacterial shapes, what is the
shape of this species?
Answer Option 2 - Curved rod
Explanation:Vibrio's unique curved rod shape is also called the "comma" shape. Just helps to
remember it more easily

2. 5. Legionella pneumophilia can grow in water and is transmitted in aerosols. Which of these has
an infection NOT been linked to?
Answer option 4 -ocean water
6. On a global scale, the most important waterborne bacterial pathogens are __________.
Answer Option 4 -Vibrio cholerae and Salmonella enterica serovar Typhi
7. Food that is heavily salted or candied does not need to be refrigerated. Why not?
Answer option 2 -Extremely concentrated solutions are very hypertonic and therefore desiccate
microorganisms. As a result, there is no need for lower temperatures through refrigeration to
slow growth.
8. Microbes capable of fermentation are often used in food. What is the main function of
fermentation for the microbes?
Answer option 3 -Fermentation makes large quantities of ATP to compensate for the lack of an
electron transport chain.
9. Why are antibiotics often ineffective in treating food poisoning (food intoxication)?
Answer Option 1 -Antibiotics target bacteria; they do not damage toxins.
10. Staphyloccocus aureus is an important cause of food poisoning. There are several genes
associated with S. aureus that encode exotoxins associated with food poisoning. SEA is a S.
aureus exotoxin encoded by a viral gene. What sort of life cycle must the phage have?
Answer Option 4 - Lysogenic
11. Reheating food to a temperature sufficient to kill bacteria is helpful in making food safer.
However, is there a way that one can get food poisoning from food despite its having been
heated in this way?
Answer Option 4 -In some cases, toxins may be heat-stable above temperatures that kill
bacteria.
Solution
1. Water supplies are treated with chlorine to kill pathogens. Chlorine reacts well with many
other chemicals because it is a strong oxidant. What does this mean?
Answer: Option 4 Because chlorine is strongly electronegative and needs one electron to fill its
outer shell, it strongly pulls electrons from other substances.
Explanation: Chlorine is known to be one of the most electronegative atoms of the periodic table
( with a value of approx 3 in the pauling scale). This means that it has a very strong tendancy to
attract electron. Also Chlorine (Atomic number 17, configuration of electrons 2, 8, 7) has seven
electrons in the valence shell so it needs one electron to fill its outer shell .
2. Tests to monitor water safety often report the number of fecal coliform bacteria found in

3. samples. Which of the following statements accurately reflects water safety recommendations
based upon fecal coliform levels?
Answer : Here by mistake the first two options are exactly same, one of them probably needs to
be corrected to
If the level of fecal coliform bacteria is low, then the water is safe for drinking and recreational
purposes.
This option will be the correct option.
Explanation: Fecal coliforms are bacteria which indicate that the water might have been exposed
to fecal matter. They are an excellant proxy to make sure that the water doesn't contain any
human pathogens. So if the Fecal coliforms count is low it indicates that the chances of water
containing any human pathogen is also low and therefore it can be used for drinking and
recreational purposes
3. When an individual has severe diarrhea, as can occur with cholera, rehydration solution with
glucose, salt, sodium bicarbonate, and potassium chloride can be administered. Why is it
important to use a solution like this rather than simply giving the individual water?
Answer: Option 1: Diarrhea causes the loss of electrolytes, not just fluids, and it is important to
replace the electrolytes as well. Glucose is transported into intestinal epithelial cells, along with
sodium, by symporters. It is included as well because glucose is not sufficiently absorbed while
sodium is lacking.
Explanation: The answer is self explanatory
4.Vibrio cholerae is a human pathogen that causes cholera. It has an unusual shape distinctive of
its genus. Considering that it does not have one of the most common bacterial shapes, what is the
shape of this species?
Answer Option 2 - Curved rod
Explanation:Vibrio's unique curved rod shape is also called the "comma" shape. Just helps to
remember it more easily
5. Legionella pneumophilia can grow in water and is transmitted in aerosols. Which of these has
an infection NOT been linked to?
Answer option 4 -ocean water
6. On a global scale, the most important waterborne bacterial pathogens are __________.
Answer Option 4 -Vibrio cholerae and Salmonella enterica serovar Typhi
7. Food that is heavily salted or candied does not need to be refrigerated. Why not?
Answer option 2 -Extremely concentrated solutions are very hypertonic and therefore desiccate
microorganisms. As a result, there is no need for lower temperatures through refrigeration to
slow growth.
8. Microbes capable of fermentation are often used in food. What is the main function of

4. fermentation for the microbes?
Answer option 3 -Fermentation makes large quantities of ATP to compensate for the lack of an
electron transport chain.
9. Why are antibiotics often ineffective in treating food poisoning (food intoxication)?
Answer Option 1 -Antibiotics target bacteria; they do not damage toxins.
10. Staphyloccocus aureus is an important cause of food poisoning. There are several genes
associated with S. aureus that encode exotoxins associated with food poisoning. SEA is a S.
aureus exotoxin encoded by a viral gene. What sort of life cycle must the phage have?
Answer Option 4 - Lysogenic
11. Reheating food to a temperature sufficient to kill bacteria is helpful in making food safer.
However, is there a way that one can get food poisoning from food despite its having been
heated in this way?
Answer Option 4 -In some cases, toxins may be heat-stable above temperatures that kill
bacteria.