Evidence Suggests That Factors Which Contribute Towards the Virulence of E.coli

question 58

Multiple Choice

Evidence suggests that factors which contribute towards the virulence of E.coli strain O157:H7,a bacterial strain reported to cause 2,100 hospitalizations in the US annually,are caused by genes from a virus that infects bacteria.Considering this evidence,which statement most likely explains how the O157:H7 population acquired the genetic variation that distinguishes the strain from harmless E.coli strains,such as those that reside in our intestines?

• A)The virus entered the bacterial cell allowing the bacteria's cellular machinery to create new viruses.
• B)Viral envelope proteins bind to receptors on the bacterial membrane, allowing the viral genetic material to enter the bacterium and become translated into proteins.
• C)The virus entered the cell and acquired specific genes from the bacteria to increase the virulence of the virus.
• D)The virus infected the bacterium, and allowed the bacterial population to replicate with a copy of the phage genome in each new bacterium.
• E)The virus entered the cell and resulted in mutation of bacterial genes.

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Definitions:

Economic Profits

Profits exceeding the opportunity costs of a firm, representing earnings beyond the breakeven point.

Economic Costs

The total value of all resources used to produce a good or service, including both explicit and implicit costs.

Accounting Profit

The difference between total revenue and explicit costs; it does not account for implicit costs, unlike economic profit.

Total Revenue

The entire amount of income generated by the sale of goods or services before any costs are subtracted.