Hermine E. Smikle
Topic: Probability
Purpose: To calculate the likelihood of cultivating a specific species of bacteria.
Objectives: Students will be able to apply the Poisson distribution to growth of bacteria.
Background Information:
It is assumed that a large number of samples of bacteria are present in the drinking water, then the Poisson distribution can be used to describe the pattern of results that is likely to occur.
Problem:
In a lab experiment to grow bacteria in a Petri dish, the bacteria will grow at a rate of 100 per second.
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a) Find the probability of 100 that fewer bacteria will be found in a 1- second period.
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b) Find the probability that at least 100 bacteria will be in the dish in a 30 second
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period.
Glossary of Terms
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Attachment; first step in viral infection, the virus binds to a specific receptor on the host's cell.
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2.
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Bacteria: prokaryotic microbes with rigid cell walls
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3.
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Binary fission: division process in which each cell divides into two cells. This makes the cell population increase exponentially.
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4.
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Emerging infectious diseases: These are diseases that have appeared in a population, and or diseases that have existed in the past, but are rapidly increasing.
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5.
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Envelope: layer of protein surrounding some viruses
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6.
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Genome: refers to the entire collection of genes within an individual. In bacteria, these genes can be located in the bacterium's chromosomes as well as in genetic elements such as plasmids that are inside the cell cytoplasm.
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7.
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Generation time: the amount of time it takes bacteria or viral genome to divide
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8.
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Parenteral transmission: Transmission by needle
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Pathogen: organism capable of causing diseases
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10.
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Plasmids: are autonomous lengths of DNA that replicate independently from
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bacteria chromosomes.
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11.
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Ribosome: is the collection of proteins and different ribosomal RNA molecules
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that form the site of protein syntheses.
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12.
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Systemic: affecting the whole system
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13.
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Virion: an entire virus particle
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14.
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Virus: microorganism that must replicate by using the biosynthetic machinery of
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free- living organisms.
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