Use the Following Information to Answer the Next Few Questions

question 17

Multiple Choice

Use the following information to answer the next few questions.
A eukaryotic gene has "sticky ends" produced by the restriction endonuclease EcoRI. The gene is added to a mixture containing EcoRI and a bacterial plasmid that carries two genes conferring resistance to ampicillin and tetracycline. The plasmid has one recognition site for EcoRI located in the tetracycline resistance gene. This mixture is incubated for several hours, exposed to DNA ligase, and then added to bacteria growing in nutrient broth. The bacteria are allowed to grow overnight and are streaked on a plate using a technique that produces isolated colonies that are clones of the original. Samples of these colonies are then grown in four different media: nutrient broth plus ampicillin, nutrient broth plus tetracycline, nutrient broth plus ampicillin and tetracycline, and nutrient broth without antibiotics.
-Bacteria that do not take up any plasmids would grow on which media?

• A) the nutrient broth only
• B) the nutrient broth and the tetracycline broth
• C) the nutrient broth and the ampicillin broth
• D) the tetracycline broth and the ampicillin broth
• E) all three broths

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Definitions:

Four-Firm Concentration

is a metric that measures the total market share held by the four largest firms within an industry, indicating the level of market concentration and competition.

Barriers to Entry

Obstacles that make it difficult for new competitors to enter a market.

Oligopoly

A market structure characterized by a small number of firms whose decisions about production and pricing significantly affect the market.

Herfindahl Index

A measure of market concentration that sums the squares of the market share percentages of all firms within the industry, used to assess the level of competition.