Use the Following Information When Answering the Corresponding Question(s)

question 9

Multiple Choice

Use the following information when answering the corresponding question(s) .
The lac operon is used in countless ways for genetics research and biotechnology.One important use of the lac operon is to regulate the expression of cloned genes.In this application,some regulatory elements of the operon are fused to the cloned gene that is to be regulated.One application of such technology was reported by Cronin et al. ,The lac operator-repressor system is functional in the mouse,Genes and Development 15 (2001) :1506-17.These investigators fused a portion of the lac operon to the mouse tyrosinase gene,a gene required for pigment production.This recombinant DNA,composed of E.coli lac operon sequences and the mouse tyrosinase gene,was introduced into albino mice using techniques that will be described in Chapter 19.Using the lac operon regulatory sequences,the investigators were able to regulate tyrosinase gene expression.In fact,they were able to convert albino (white) mice into brown mice.The following questions ask you to use your knowledge of the lac operon to deduce how Cronin et al.were able to regulate tyrosinase gene expression in mice.
-Refer to the paragraph about the lac operon experiment by Cronin et al.Controlling the production of a pigment is interesting,but in itself seems more a stunt than a valuable research endeavor.What is the broader significance of the results of Cronin et al.?

• A)The same genetic system will potentially cure most cancers.
• B)This same genetic system potentially can be used to treat hair loss in mice and humans.
• C)This same genetic system potentially can be used to control the expression of genes involved in weight control.
• D)This same genetic system potentially can be used to control the expression of almost any gene.

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Definitions:

Contribution Margin Ratio

The contribution margin ratio is a financial metric that measures the proportion of revenue that exceeds total variable costs, indicating how much of each sale contributes to covering fixed costs.

Profit-Volume Ratio

A financial tool used to analyze the relationship between profit and sales volume, showing the impact of sales changes on profits.

Unit Contribution Margin

The dollars available from each unit of sales to cover fixed costs and provide operating profits.

Break-Even Point

The level of operations at which a company’s revenues and expenses are equal.