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BC FOODSAFE Level 1 study materials
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BC FOODSAFE Level 1 practice questions

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Question 1Food safety basics and the role of the food handler

A food handler has just finished trimming raw chicken and will now assemble a salad. What must the food handler do before touching the salad?

  1. Wipe hands on the apron and put on a fresh pair of gloves
  2. Rub in hand sanitizer and let it dry before continuing work
  3. Rinse hands under warm water and dry them on a cloth towel
  4. Wash hands with soap and warm water for 20 seconds Correct answer.

Explanation

Handwashing with soap and warm running water lifts and rinses away the bacteria picked up from raw meat. Sanitizer or water alone does not clean soiled hands, and gloves worn over unwashed hands simply carry contamination onto the salad. Hands must be washed every time the food handler moves from raw food to ready-to-eat food.

Question 2Food safety basics and the role of the food handler

Which temperature range is the danger zone in which bacteria multiply most quickly?

  1. 4 °C to 60 °C (40 °F to 140 °F) Correct answer.
  2. 74 °C to 100 °C (165 °F to 212 °F)
  3. 0 °C to 4 °C (32 °F to 40 °F)
  4. 60 °C to 74 °C (140 °F to 165 °F)

Explanation

Bacteria grow fastest between 4 °C and 60 °C, where many species can double in number roughly every 20 minutes. Food is therefore held below 4 °C or above 60 °C to slow or stop that growth. Every minute a food spends inside this band counts toward the time limits for that product.

Question 3Food safety basics and the role of the food handler

A food handler wakes up with vomiting and diarrhea. What is the correct action?

  1. Take anti-diarrheal medicine and report to work as usual
  2. Stay home, phone the manager, and return once symptoms have cleared Correct answer.
  3. Wear gloves for the whole shift and avoid ready-to-eat food
  4. Work only at the cash register where there is no food contact

Explanation

Vomiting and diarrhea are often caused by pathogens such as norovirus or Salmonella that pass easily from hands to food and to coworkers. The food handler must stay away from work, tell the manager about the symptoms, and return only after being symptom-free for the period required by the regulations.

Question 4Food safety basics and the role of the food handler

A food handler has just cut raw chicken on a cutting board and now needs to chop lettuce. What should be done with the cutting board?

  1. Wipe the board with a damp cloth and dry it with a paper towel
  2. Rinse the board under hot water and continue chopping
  3. Turn the board over and use the clean underside
  4. Wash and sanitize the board before using it again Correct answer.

Explanation

Juices from raw chicken can carry pathogens such as Campylobacter and Salmonella that will transfer to lettuce, which is eaten without cooking. The board must be washed in detergent, rinsed, and sanitized, or replaced with a clean one, whenever it moves from raw food to ready-to-eat food.

Question 5Food safety basics and the role of the food handler

Egg salad sandwiches have been sitting on a buffet table at room temperature. What is the longest time they may stay there before they must be discarded?

  1. 1 hour
  2. 4 hours
  3. 2 hours Correct answer.
  4. 6 hours

Explanation

Potentially hazardous food that sits in the danger zone builds up time toward the two-hour limit. After a cumulative two hours at room temperature, bacteria may have multiplied enough to cause illness, so the sandwiches must be thrown out. The time counts even if the food is moved in and out of the cooler.

Question 6Food safety basics and the role of the food handler

A food handler needs to cool a large pot of hot stew quickly and safely. Which method should be used?

  1. Cover the full pot and place it in the cooler
  2. Divide it into shallow pans and refrigerate uncovered Correct answer.
  3. Leave the covered pot on the counter to cool overnight
  4. Place the full pot in the freezer and cover it tightly

Explanation

Cooling must happen fast: from 60 °C down to 20 °C within two hours, and on to 4 °C within four more hours. Shallow, uncovered pans expose more surface area and let heat escape, while a deep covered pot traps heat in the centre where bacteria can multiply.

Question 7Food safety basics and the role of the food handler

A food handler is inspecting a delivery. Which finding means the product should be refused?

  1. Milk cartons at 3 °C (38 °F) with intact seals
  2. Lettuce in clean, dry crates with no wilting
  3. Frozen chicken with ice crystals and soft flesh Correct answer.
  4. Canned goods with labels that are slightly torn

Explanation

Soft flesh and ice crystals on frozen chicken show that it thawed and was refrozen, meaning it spent time in the danger zone where bacteria multiply. Cold milk, sound produce, and intact canned goods are acceptable deliveries. Any temperature-abused or damaged product should be rejected at the door.

Question 8Food safety basics and the role of the food handler

What is the correct sequence for manually washing dishes in a three-compartment sink?

  1. Wash in detergent, sanitize, rinse, then towel dry
  2. Rinse, wash in detergent, air dry, then sanitize
  3. Wash in detergent, rinse, sanitize, then air dry Correct answer.
  4. Sanitize, wash in detergent, rinse, then towel dry

Explanation

Equipment is washed in hot detergent water to strip grease and food, rinsed so the soil is carried away, then immersed in sanitizer for the required contact time. Air drying lets the sanitizer finish working and avoids recontaminating clean surfaces with a towel.

Question 9Food safety basics and the role of the food handler

A food handler finds fresh rodent droppings on a shelf in the dry storage room. What is the most appropriate action?

  1. Stop work, keep food away, and report it to the manager at once Correct answer.
  2. Spray the shelf with sanitizer and put the products back
  3. Sweep up the droppings and continue stocking the shelf
  4. Set out traps and mention it to the manager at the end of the shift

Explanation

Droppings show an active pest infestation and can carry pathogens, so the area must be reported immediately. The manager can then hold or discard exposed products, clean and sanitize the space, and arrange professional pest control. Cleanup of droppings should be done only by staff trained in the precautions it requires.

Question 10Food safety basics and the role of the food handler

Which is a safe way to thaw frozen chicken breasts?

  1. In the microwave and then left on the counter until needed
  2. In the refrigerator at 4 °C or colder Correct answer.
  3. On the kitchen counter at room temperature
  4. In a sink filled with warm standing water

Explanation

Thawing under refrigeration keeps the chicken below 4 °C, so any bacteria present cannot multiply rapidly while the meat defrosts. Thawing on the counter or in warm water warms the outer surface while the centre is still frozen, leaving the meat in the danger zone for hours.

Question 11Food safety basics and the role of the food handler

What is the minimum time a food handler should scrub their hands with soap and warm water during handwashing?

  1. 60 seconds
  2. 5 seconds
  3. 10 seconds
  4. 20 seconds Correct answer.

Explanation

Food handlers should scrub their hands with soap and warm running water for at least 20 seconds, then rinse and dry with a single-use towel. This contact time helps lift and remove transient bacteria and viruses from the skin. Scrubbing for only a few seconds is not enough to reduce contamination safely.

Question 12Food safety basics and the role of the food handler

Which item is acceptable for a food handler to wear on their hands while preparing food?

  1. Artificial nails with polish
  2. A plain metal wedding band Correct answer.
  3. A wristwatch with a fabric strap
  4. A ring with small stones

Explanation

Food handlers may wear a plain metal band such as a wedding ring, but other jewelry can trap food and bacteria. Watches, stones, and artificial nails are not permitted because they are difficult to clean and can fall into food.

Question 13Food safety basics and the role of the food handler

A food handler with shoulder-length hair is preparing sandwiches. What is the appropriate hair control?

  1. Use hairspray to hold hair in place
  2. Tie hair back and wear a hair restraint Correct answer.
  3. Wear a cap only when customers can see
  4. Leave hair loose but avoid touching it

Explanation

Hair must be restrained so it cannot fall into food or be touched repeatedly by the food handler. Shoulder-length hair should be tied back and covered with a hat, hairnet, or similar restraint. Loose hair is both a physical and bacterial contaminant.

Question 14Food safety basics and the role of the food handler

In a walk-in cooler, where should raw ground beef be stored relative to ready-to-eat deli meat?

  1. On the floor under the shelves
  2. On the same shelf beside the deli meat
  3. On the top shelf above the deli meat
  4. On a lower shelf beneath deli meat Correct answer.

Explanation

Raw animal foods must be stored below ready-to-eat foods so that juices cannot drip onto them. Ground beef should sit on a lower shelf than deli meat, and it should also be below whole cuts and above raw poultry according to the usual hierarchy.

Question 15Food safety basics and the role of the food handler

How should a food handler confirm that a chlorine sanitizing solution is at the correct concentration?

  1. Smell the solution for a strong chlorine odour
  2. Check the solution's colour by eye
  3. Use the correct test strips for the sanitizer Correct answer.
  4. Add extra sanitizer until the solution feels slippery

Explanation

Sanitizer strength must be checked with the test strips made for that specific chemical, because concentration affects whether germs are killed. Colour and smell are not reliable indicators. The solution should be mixed to the manufacturer's stated concentration and remade when it falls out of range.

Question 16Food safety basics and the role of the food handler

Between wiping tables, where should a reusable wiping cloth be kept?

  1. In a pocket of the apron
  2. In a bucket of clean rinse water
  3. Folded dry on the counter
  4. In a sanitizing solution bucket Correct answer.

Explanation

Reusable wiping cloths should be stored in a bucket of correctly mixed sanitizing solution between uses. This keeps the cloth wet with sanitizer and prevents it from spreading bacteria from one surface to another. Dry or rinse-water cloths can move contamination around the kitchen.

Question 17Food safety basics and the role of the food handler

What internal temperature must previously cooked food reach when it is reheated for hot holding?

  1. 82°C (180°F)
  2. 60°C (140°F)
  3. 74°C (165°F) Correct answer.
  4. 68°C (155°F)

Explanation

Previously cooked food that will be hot held must be reheated to 74°C (165°F) throughout within two hours. This high temperature kills vegetative bacteria that may have grown during cooling and storage. Lower temperatures may warm the food without making it safe.

Question 18Food safety basics and the role of the food handler

A food handler needs to dispose of a bucket of mop water. Where should it be poured?

  1. Into the utility sink or mop sink Correct answer.
  2. Into the floor drain by the prep table
  3. Into the three-compartment dish sink
  4. Into the handwashing sink

Explanation

Handwashing sinks are dedicated to handwashing and must not be used for dumping mop water or other waste. Pouring dirty water there can splash contaminants onto the sink and nearby clean items. Waste water should go into a utility sink, mop sink, or floor drain designed for that purpose.

Question 19Food safety basics and the role of the food handler

A container of cooked pasta salad made on site is stored at 4°C (40°F). What is the maximum time it may be kept before discarding?

  1. 7 days Correct answer.
  2. 14 days
  3. 24 hours
  4. 3 days

Explanation

Ready-to-eat, potentially hazardous food that is prepared on site and held at 4°C (40°F) or colder may be kept for a maximum of seven days. The day of preparation counts as day one. After that date the food must be discarded, even if it still looks and smells acceptable.

Question 20Food safety basics and the role of the food handler

A food handler is calibrating a probe thermometer using the ice-point method. What temperature should the thermometer read in a properly prepared ice-water bath?

  1. 4°C (40°F)
  2. 0°C (32°F) Correct answer.
  3. 100°C (212°F)
  4. -18°C (0°F)

Explanation

In the ice-point method, a probe thermometer is placed in a well-stirred ice-water bath and should read 0°C (32°F). If it does not, the thermometer is adjusted to that reading before use. This check confirms the thermometer is accurate at cold temperatures.

Question 21Food safety basics and the role of the food handler

A food handler returns to the kitchen after a scheduled break and is about to prepare sandwiches. What should the food handler do first?

  1. Wash hands with soap and warm water Correct answer.
  2. Change into a clean apron before starting
  3. Wipe the sandwich prep counter with a dry cloth
  4. Put on a clean pair of disposable gloves

Explanation

Hands must be washed with soap and warm water before beginning food preparation and after breaks, because hands can carry bacteria to food. Gloves and clean clothing do not replace handwashing.

Question 22Food safety basics and the role of the food handler

What is the minimum internal temperature that poultry must reach when it is cooked?

  1. 63°C (145°F)
  2. 71°C (160°F)
  3. 74°C (165°F) Correct answer.
  4. 82°C (180°F)

Explanation

Poultry must reach 74°C (165°F) throughout to kill harmful bacteria such as Salmonella. A probe thermometer should be inserted into the thickest part to confirm the temperature.

Question 23Food safety basics and the role of the food handler

A food handler has a small cut on their finger. What is the safest way to continue preparing food?

  1. Rinse the cut under water and continue preparing food with bare hands
  2. Put a disposable glove directly over the cut without any bandage
  3. Cover the cut with an ordinary bandage and continue without wearing a glove
  4. Cover the cut with a waterproof bandage, then wear a glove Correct answer.

Explanation

A cut must be completely covered with a waterproof bandage, and a glove should be worn over it to prevent blood or bacteria from contacting food. If the wound cannot be covered properly, the handler should not work with exposed food.

Question 24Food safety basics and the role of the food handler

A customer tells a food handler that they have a severe peanut allergy. What should the food handler do?

  1. Tell the supervisor and use clean equipment to avoid cross-contact Correct answer.
  2. Reassure the customer that heating the food destroys the peanut protein
  3. Suggest the customer order a different item without checking ingredients
  4. Remove visible peanuts from the dish and then serve it to the customer

Explanation

Allergens are not reliably destroyed by cooking, and even tiny amounts can cause a severe reaction. The handler must notify the supervisor and prevent cross-contact by using clean utensils, surfaces, and ingredients.

Question 25Food safety basics and the role of the food handler

Where should cleaning chemicals be stored in a food establishment?

  1. Under the prep table beside clean cutting boards
  2. Next to dry ingredients so staff can find them easily
  3. In a designated area away from food Correct answer.
  4. On the top shelf directly above food preparation areas

Explanation

Chemicals must be kept in a separate, labeled area away from food, utensils, and packaging to prevent accidental contamination or poisoning. Storing them near food increases the risk of spills or mistaken use.

Question 26Food safety basics and the role of the food handler

A food handler sees a coworker sneeze directly onto a cutting board that was just used to chop ready-to-eat vegetables. What should the food handler do?

  1. Stop the coworker, discard the vegetables, and sanitize the board Correct answer.
  2. Turn the cutting board over and use the other side for the vegetables
  3. Wipe the cutting board with a dry cloth and then continue chopping the vegetables
  4. Rinse the cutting board with warm water and continue chopping

Explanation

Sneeze droplets carry bacteria and viruses that can contaminate ready-to-eat food. The contaminated food must be discarded, and the board must be washed, rinsed, and sanitized before reuse.

Question 27Food safety basics and the role of the food handler

A food handler checks the walk-in cooler and finds the temperature is 6°C (43°F), above the required 4°C (40°F). What is the most appropriate action?

  1. Lower the thermostat and recheck the temperature at the end of the shift
  2. Notify the supervisor and move the food to a safe cooler Correct answer.
  3. Turn off the cooler for an hour to let it reset
  4. Ignore the reading because 6°C is close to 4°C

Explanation

A temperature outside the safe limit requires corrective action: the handler should report it immediately and help move potentially hazardous food to a safe cooler. Delaying action allows bacteria to multiply.

Question 28Food safety basics and the role of the food handler

A food handler is asked to serve jam that a customer made at home and brought in. What is the best response?

  1. Serve it only to the customer who brought the jar
  2. Refuse it and explain that food must come from an approved source Correct answer.
  3. Taste a small amount first to check that it seems safe
  4. Serve it if the jar looks clean and the lid appears to be sealed

Explanation

Food served in a food establishment must come from approved, inspected sources; home-canned or home-prepared foods are not allowed because their safety cannot be verified. The handler should refuse politely and inform the supervisor if needed.

Question 29Microorganisms and causes of foodborne illness

Bacteria that cause foodborne illness multiply fastest within which temperature range?

  1. 4°C to 60°C (40°F to 140°F) Correct answer.
  2. 60°C to 74°C (140°F to 165°F)
  3. 0°C to 4°C (32°F to 40°F)
  4. -18°C to 0°C (0°F to 32°F)

Explanation

The range from 4°C to 60°C is called the temperature danger zone, and bacteria such as Salmonella and Staphylococcus aureus reproduce most rapidly there. Holding food below 4°C slows growth, while thorough cooking above 60°C kills most vegetative cells. Food should therefore spend as little time as possible within this range.

Question 30Microorganisms and causes of foodborne illness

In the acronym FATTOM, the two letters T stand for which pair of conditions that bacteria need in order to grow?

  1. Toxins and tissue
  2. Texture and thickness
  3. Transparency and turbidity
  4. Temperature and time Correct answer.

Explanation

FATTOM lists the conditions bacteria need in order to multiply: food, acidity, temperature, time, oxygen and moisture. The two T's are temperature and time, which is why rapid cooling and strict time limits are core food safety controls. Food left in the danger zone for a long period gives bacteria more opportunity to multiply.

Question 31Microorganisms and causes of foodborne illness

Which of these foods is considered potentially hazardous and needs strict temperature control?

  1. Dry pasta stored in a cupboard
  2. White vinegar in a closed bottle
  3. Cut melon held at room temperature Correct answer.
  4. Whole black peppercorns in a sealed jar

Explanation

Potentially hazardous foods are moist and low in acid, so they support rapid bacterial growth. Cutting melon exposes moist, low-acid flesh to contamination and to room temperature, so it must be refrigerated. Dry pasta, whole peppercorns and vinegar do not supply the moisture and low acidity that bacteria need.

Question 32Microorganisms and causes of foodborne illness

Home-canned low-acid vegetables are a botulism concern mainly because Clostridium botulinum...

  1. grows only at temperatures above 60°C (140°F)
  2. is completely destroyed by boiling during canning
  3. needs plenty of oxygen in order to multiply
  4. can multiply in sealed jars without oxygen Correct answer.

Explanation

Clostridium botulinum is an anaerobic, spore-forming bacterium, meaning it grows where oxygen is absent. A sealed jar of low-acid vegetables provides exactly that oxygen-free, moist, low-acid environment. Its spores survive ordinary boiling, and the toxin formed in the jar is not reliably destroyed by brief reheating, so pressure canning is required.

Question 33Microorganisms and causes of foodborne illness

Cooked rice that is left at room temperature overnight and only briefly reheated is most often associated with which foodborne illness?

  1. Listeriosis
  2. Bacillus cereus food poisoning Correct answer.
  3. Trichinellosis
  4. Hepatitis A infection

Explanation

Bacillus cereus forms spores that survive ordinary cooking, and those spores germinate when cooked rice is cooled slowly and held at room temperature. The bacteria then produce toxins that are heat-stable, so quick reheating does not make the rice safe. Rice should be cooled quickly and refrigerated within a short time.

Question 34Microorganisms and causes of foodborne illness

A food handler with an infected cut on the hand prepares a ham sandwich that is then held unrefrigerated for several hours. Which organism is most likely to produce toxin in that sandwich?

  1. Giardia lamblia
  2. Clostridium botulinum
  3. Hepatitis A virus
  4. Staphylococcus aureus Correct answer.

Explanation

Staphylococcus aureus lives in the nose, throat and skin and in infected wounds, and it is easily transferred to food by unwashed hands. A moist, protein-rich food such as ham held at room temperature lets the organism multiply and produce toxin. That toxin is heat-stable, so reheating the sandwich would not make it safe.

Question 35Microorganisms and causes of foodborne illness

Which statement best describes viruses such as norovirus and hepatitis A in relation to food?

  1. They are reliably destroyed by freezing the food
  2. They multiply quickly in food kept at room temperature
  3. They are controlled by adding antibiotics to the food
  4. They cannot multiply in food but can survive on it Correct answer.

Explanation

Viruses need a living host cell in order to reproduce, so they cannot increase in number while sitting on food. Food and water act mainly as vehicles that carry the virus to the person who eats it. Freezing does not inactivate them, so the key controls are handwashing, excluding ill workers and using safe water.

Question 36Microorganisms and causes of foodborne illness

Why is Listeria monocytogenes a particular concern in refrigerated ready-to-eat foods such as deli meats and soft cheeses?

  1. It can only survive inside oxygen-free packages
  2. It forms spores that survive every cooking temperature
  3. It can multiply slowly at refrigerator temperatures Correct answer.
  4. It is a virus that spreads readily through the air

Explanation

Listeria is unusual because it can grow at temperatures close to and even below normal refrigeration, so cold storage does not stop it. Ready-to-eat foods are eaten without a further cooking step that would kill the bacteria. This is why date marking, strict cold holding and cleaning of slicers matter so much.

Question 37Microorganisms and causes of foodborne illness

A jarred sauce has a measured pH of 4.2. What does this tell you about its ability to support the growth of foodborne bacteria?

  1. It is an ideal environment for Salmonella and Clostridium botulinum
  2. It must be kept frozen, because acidity speeds bacterial growth
  3. Its acidity has no effect at all on bacterial growth; only temperature matters
  4. Most foodborne bacteria cannot grow in it, though moulds and yeasts can Correct answer.

Explanation

Foodborne bacteria grow best at a pH close to neutral, and most are inhibited below about pH 4.6. A sauce at pH 4.2 is therefore unlikely to support bacterial growth, which is why acidified foods are a recognised preservation method. The acidity does not, however, prevent spoilage yeasts or moulds.

Question 38Microorganisms and causes of foodborne illness

A bag of shelled peanuts shows visible mould on some of the nuts. What is the safest action, and why?

  1. Bake the nuts, because oven heat destroys any mould toxin present
  2. Discard the whole bag, as mould toxins spread and resist heat Correct answer.
  3. Keep the unspoiled-looking nuts, because only the mouldy nuts are a hazard
  4. Rinse the nuts in water, because mould grows only on the surface

Explanation

Some moulds produce mycotoxins, such as aflatoxin, which are not destroyed by normal cooking and can spread beyond the visible patch of mould. Because the toxin cannot be seen or tasted, parts of the food that look fine may still be contaminated. Discarding the affected batch is the only reliable way to remove the risk.

Question 39Microorganisms and causes of foodborne illness

Under ideal conditions, roughly how much time does a foodborne bacterium need to double its numbers in food?

  1. About twenty-four hours
  2. About twenty minutes Correct answer.
  3. About eight hours
  4. About two hours

Explanation

Bacteria reproduce by dividing in two, and when food, moisture and warmth are right, a population can double roughly every twenty minutes. This means a few hours of temperature abuse can turn a tiny contamination into millions of cells. That rapid doubling is the reason food should not sit in the danger zone for more than two hours.

Question 40Microorganisms and causes of foodborne illness

Which of these foods is the most common source of Salmonella in a kitchen?

  1. Pasteurized milk
  2. Commercially canned vegetables
  3. Raw poultry and eggs Correct answer.
  4. Cooked white rice

Explanation

Salmonella lives in the intestines of birds and other animals, so raw poultry, eggs and their juices commonly carry it. Thorough cooking and keeping raw juices away from ready-to-eat food are the key controls. Cross-contamination from a cutting board or hands is just as important as undercooking.

Question 41Microorganisms and causes of foodborne illness

Which of these preservation methods works mainly by removing the water that microorganisms need?

  1. Vacuum packaging
  2. Refrigeration
  3. Canning in a sealed jar
  4. Drying Correct answer.

Explanation

Microorganisms need available water to multiply, and drying removes that water so bacteria and moulds cannot grow. The organisms are not necessarily killed, so dried foods must be kept dry during storage. Adding salt or sugar works in a similar way by tying up the water that would otherwise be available.

Question 42Microorganisms and causes of foodborne illness

A young child is served a hamburger made from ground beef that was still pink in the middle. Which pathogen is the greatest concern?

  1. Mould growing on the lettuce leaf
  2. Clostridium botulinum spores
  3. Staphylococcus aureus growing in the bun
  4. Escherichia coli O157:H7 Correct answer.

Explanation

Grinding mixes bacteria from the surface throughout the meat, so the centre of a patty must reach a safe internal temperature. Escherichia coli O157:H7 is the pathogen of concern and can cause severe, sometimes life-threatening illness, especially in young children. A pink centre in a ground patty signals that the required temperature was not reached.

Question 43Microorganisms and causes of foodborne illness

Fish that will be eaten raw, such as sushi, must be treated to control parasites. Which treatment is effective?

  1. Holding the fish at 4°C (40°F) for twenty-four hours
  2. Briefly cold-smoking the fish over wood chips
  3. Freezing at a set temperature for a set time Correct answer.
  4. Rinsing the fillets with lemon juice or vinegar before serving

Explanation

Parasites such as Anisakis survive ordinary refrigeration and acidic marinades, so only adequate freezing or thorough cooking reliably destroys them. Freezing must reach a specified temperature and be held for a specified time to be effective. Refrigeration slows spoilage but does not make raw fish parasitologically safe.

Question 44Microorganisms and causes of foodborne illness

A container of leftover soup looks, smells and tastes completely normal. What can you correctly conclude about its safety?

  1. It may still contain harmful microorganisms Correct answer.
  2. It is safe as long as no mould is visible on the surface
  3. It is safe, because pathogens always change the look or smell of food
  4. It is safe if it was boiled when it was first made

Explanation

Spoilage organisms usually create off-odours, slime and visible changes, but the pathogens that cause illness can multiply without producing any noticeable sign. Appearance, smell and taste are therefore not reliable tests of safety. Only proper time and temperature control keeps food safe.

Question 45Microorganisms and causes of foodborne illness

A cafeteria cooks a large, deep pot of beef stew and leaves it on the counter to cool overnight. Which organism is most likely to multiply and cause illness?

  1. Clostridium perfringens Correct answer.
  2. Staphylococcus aureus from handling
  3. Trichinella spiralis from undercooked pork
  4. Hepatitis A virus carried on the cook's hands

Explanation

Clostridium perfringens grows in moist protein foods and survives ordinary cooking as heat-resistant spores. A deep pot cools very slowly, so the stew stays in the warm danger zone for many hours and the spores germinate and multiply. Cooling in shallow pans and reheating thoroughly are the required controls.

Question 46Microorganisms and causes of foodborne illness

An opened bottle of fruit juice left at room temperature becomes fizzy and smells fermented. Which type of microorganism is most likely responsible?

  1. Yeasts Correct answer.
  2. Hepatitis A virus
  3. Bacteria such as Salmonella
  4. Parasites such as Giardia

Explanation

Yeasts tolerate high sugar and acid conditions that stop most bacteria from growing, and they ferment sugars into gas and alcohol. That fermentation produces the fizz and the fermented smell. Their activity is evidence of spoilage rather than proof that a pathogen is present.

Question 47Microorganisms and causes of foodborne illness

Which statement best describes the effect of freezing on microorganisms in food?

  1. It kills only bacteria that form spores
  2. It destroys any toxins the bacteria have produced
  3. It stops growth but does not kill microorganisms Correct answer.
  4. It makes pathogens multiply faster than at room temperature

Explanation

Cold storage, including freezing, only suspends microbial activity; most bacteria, viruses and parasites survive and resume multiplying once the food thaws. That is why freezing cannot be counted on to make a contaminated food safe. Thawing method matters too, because food left on the counter spends hours in the danger zone.

Question 48Microorganisms and causes of foodborne illness

A food contains a heat-stable bacterial toxin such as the one produced by Staphylococcus aureus. The food is then boiled for ten minutes. What is the most likely result?

  1. The toxin is destroyed, so the food becomes safe
  2. The toxin turns into harmless spores
  3. The toxin becomes more toxic when heated
  4. The toxin survives and remains harmful Correct answer.

Explanation

Boiling kills living bacterial cells but does not reliably destroy toxins that have already formed in the food, because those toxins are heat stable. Illness in these cases is caused by the toxin itself, and onset can be rapid after eating. Reheating therefore cannot rescue food that has been temperature abused.

Question 49Microorganisms and causes of foodborne illness

Which bacterium is most closely linked to raw poultry and to cross-contamination from poultry juices?

  1. Staphylococcus aureus
  2. Clostridium botulinum
  3. Campylobacter jejuni Correct answer.
  4. Aspergillus flavus

Explanation

Campylobacter jejuni commonly lives in the intestines of poultry, and juices from raw chicken can transfer it to hands, utensils, and ready-to-eat foods. Thorough cooking of poultry and careful cleaning of contact surfaces reduce this risk.

Question 50Microorganisms and causes of foodborne illness

Which parasite is a recognized concern in undercooked pork or lamb?

  1. Toxoplasma gondii Correct answer.
  2. Anisakis simplex
  3. Giardia lamblia
  4. Entamoeba histolytica

Explanation

Toxoplasma gondii can form tissue cysts in the muscle of infected pigs and sheep, and these cysts are destroyed by thorough cooking. Handling raw meat and then touching the mouth can also transfer the parasite.