Give one precaution scientists use when working with microorganisms in the laboratory - Leaving Cert Biology - Question 11 - 2022
Question 11
Give one precaution scientists use when working with microorganisms in the laboratory.
Explain the terms asepsis and sterility as applied to living organisms.
(i) ... show full transcript
Worked Solution & Example Answer:Give one precaution scientists use when working with microorganisms in the laboratory - Leaving Cert Biology - Question 11 - 2022
Step 1
Give one precaution scientists use when working with microorganisms in the laboratory.
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Answer
One precaution that scientists use when working with microorganisms is to ensure proper aseptic techniques. This includes using disinfectants to clean surfaces, wearing gloves, and sterilizing equipment to prevent contamination.
Step 2
Explain the terms asepsis and sterility as applied to living organisms.
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Asepsis refers to the absence of pathogenic microorganisms in a given environment. It is crucial in laboratory settings to avoid contamination. Sterility, on the other hand, means that no viable pathogens exist, ensuring that materials used are completely free of all forms of life, including spores.
Step 3
Draw a large labelled diagram of a typical bacterial cell.
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Responsible for providing labels: The diagram should include components such as the cell wall, cell membrane, cytoplasm, nucleoid, ribosomes, plasmid, and flagella, illustrated clearly.
Step 4
Describe the main events of endospore formation.
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The main events of endospore formation include:
DNA replication occurs, and the cell divides asymmetrically.
The smaller part of the cell develops into the endospore.
A thick protective coat forms around the endospore.
The surrounding cell deteriorates, and the endospore is released.
Step 5
Give two examples of harmful bacteria.
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Escherichia coli (E. coli), which can cause food poisoning.
Staphylococcus aureus, known for causing skin infections.
Step 6
What is an antibiotic?
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An antibiotic is a chemical substance that inhibits the growth of or destroys bacteria, used commonly to treat bacterial infections.
Step 7
State one possible reason why antibiotic resistance has arisen in bacteria.
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One possible reason antibiotic resistance has arisen is due to the overuse and misuse of antibiotics, allowing bacteria to evolve and develop resistance mechanisms.
Step 8
Give two factors that affect the growth of microorganisms, such as bacteria.
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Temperature, as it influences enzyme activity and metabolic rates in microorganisms.
Nutrient availability, which is essential for the growth and reproduction of bacteria.
Step 9
Explain how either of the factors you named at part (c) (i) above affects growth.
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Temperature affects microbial growth by optimizing enzyme functions; for instance, temperatures that are too low may slow down metabolism, while excessively high temperatures can denature enzymes, ultimately leading to cell death.
Step 10
Distinguish between batch and continuous flow food processing by writing a brief sentence on each type.
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Batch processing involves the addition of microorganisms at the start of the process, after which nutrients are consumed until depletion, whereas continuous flow processing maintains a constant supply of nutrients and microorganisms in a steady state.
Step 11
Sketch a plot of a microorganism growth curve.
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The sketch should illustrate five growth phases: lag, log, stationary, decline, and survival, with the x-axis labeled as 'Time' and the y-axis as 'Population of organisms.' The curve should be appropriately labeled for clarity.
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