Wild type E. coli metabolizes the sugar lactose by expressing the enzyme ß-galactosidase. You have isolated a mutant that you call lac1–, which cannot synthesize ß-galactosidase and cannot grow on lactose (Lac–). During an condition Lac– strain, called lac3–, is linked to the Tn5 insertion. From a strain carrying the Tn5 insertion and lac3– mutation you isolate an F’ that caries a region of the chromosome that includes both Tn5 and the linked Lac region. Introduce this F’ into an F– strain carrying lac1– by selecting for Kanr. These merodiploids express ß-galactosidase normally. What does this result tell you about the relationship between the lac3– and lac1- mutations?  

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#Question id: 1064

#SCPH28 | Zoology

An infection in which the virus is continually present in the body is referred to as

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#Question id: 1065

#SCPH28 | Zoology

Resistance of some animals to certain viral diseases is based on

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#Question id: 1080

#SCPH01 Biochemistry

 In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

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#Question id: 1080

#SCPH06 I Botany

 In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

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#Question id: 1080

#SCPH28 | Zoology

 In the formation of biofilms, such as those forming on unbrushed teeth, cell signaling serves which function?

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#Question id: 1081

#SCPH01 Biochemistry

Which of the following is a type of local signaling in which a cell secretes a signal molecule that affects neighboring cells?