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Which one of these statements about bacteria is true?
A. All types of bacteria give food poisoning
B. Freezing makes food last longer by killing bacteria
C. Bacteria grows fastest when they are warm
D. All bacteria need air to survive

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Last updated date: 18th Jun 2024
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Answer
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Hint:
Bacteria are a variety of biological cells. They include a large domain of prokaryotic microorganisms. Generally a few micrometers in length, bacteria retain several shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats

Complete step by step answer:
Option A- All types of bacteria give food poisoning
All bacterias do not cause food poisoning. Some of them that can cause are- Campylobacter, Clostridium, perfringens, E. coli, Listeria, Norovirus, Salmonella.

Option B- Freezing makes food last longer by killing bacteria
Freezing does not destroy germs and bacteria. Rather, it virtually puts them into hibernation. They are passive while the food is frozen and will “wake up” as soon as the food thaws. However, once it is thawed, and particularly if it is allowed to stay at room temperatures, the bacteria return with a retaliation.

Option C- Bacteria grows fastest when they are warm
Bacteria grow rapidly when they are warm. Largely food poisoning bacteria grow best at 37°C, although they can increase between 5°C and 63°C. Food should not be left out at room temperature for any more than two hours. Later that time bacterial growth may be abrupt.

Option D- All bacteria need air to survive
Virtually all eukaryotic organisms require oxygen to thrive, many species of bacteria can also grow under anaerobic conditions.

So, the correct answer is C- 'Bacteria grow fastest when they are warm'

Note:

At 37°C bacteria start growing but they start multiplying between 5°C and 63°C. At room temperature, if the food is left out for any more than two hours, bacterial growth will be abrupt. All types of bacteria won't give food poisoning.
Freezing does not kill bacteria but only their growth stops. Some bacteria can withstand air like in food gravy and sauces.