A stem cell has the power to produce many different types of differentiated cells. This phenomenon is known as

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#Question id: 4890

#Unit 8. Inheritance Biology

A strain of Neurospora crassa, unable to synthesize the vitamin thiamine (t), is crossed with a strain that cannot synthesize the amino acid arginine (a). What information can be obtained from the resultant frequencies of ascospore patterns?

 A) The two loci (a) and (t) are independent assortment of each other

B) Both genes are closely linked to their respective centromeres.

C) no crossovers occurred between either gene and its centromere.

D) These two gene may reside on different chromosomes.

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#Question id: 2336

#Unit 2. Cellular Organization

Which of the following exhibit the 9 + 2 structure of microtubules?        

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#Question id: 19557

#Unit 12. Applied Biology

Cry proteins have 3 domains: domain I functions in 

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#Question id: 18729

#Unit 13. Methods in Biology

Which of the following is not a function of DNA topoisomerase?

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#Question id: 15620

#Unit 13. Methods in Biology

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?