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28. (a) Describe a feature that distinguishes a viral from a bacterial pathogen - HSC - SSCE Biology - Question 28 - 2023 - Paper 1
Question 28
28. (a) Describe a feature that distinguishes a viral from a bacterial pathogen. (b) A waterborne disease outbreak occurred after a flood. Outline an experimental... show full transcript
Worked Solution & Example Answer:28. (a) Describe a feature that distinguishes a viral from a bacterial pathogen - HSC - SSCE Biology - Question 28 - 2023 - Paper 1
Step 1
Describe a feature that distinguishes a viral from a bacterial pathogen.
Answer
One key feature that distinguishes a bacterium from a virus is their cellular composition. Bacteria are prokaryotic cellular organisms, meaning they consist of a single cell with a complex structure, including a cell membrane, cytoplasm, and genetic material. In contrast, viruses are much smaller, ranging from 0.05 to 0.1 micrometers, and consist solely of nucleic acids encased in a protein coat. They do not have cellular structures and cannot reproduce independently, as they require a host cell to replicate.
Step 2
Outline an experimental procedure that could be used to determine if the pathogen is viral or bacterial.
Answer
To determine if the pathogen from the waterborne disease outbreak is viral or bacterial, an experimental procedure can be initiated using an agar culture method. First, collect a sample of the suspected pathogen and inoculate it onto an agar plate. Incubate the plate at an appropriate temperature. If bacterial colonies grow, this indicates the presence of a bacterial pathogen. To test for a viral pathogen, a high-powered light microscope can be utilized. If no growth occurs, it would suggest the presence of a viral pathogen, as viruses do not grow on agar. Additionally, exposing the sample to antibiotics will affect bacterial pathogens, leading to their death, while having no impact on viral agents.