Exam 13: Bacterial Genetics

A plasmid has tet^r and lacZ genes for tetracycline resistance and ß-galactosidase,respectively.There is a single EcoRI site within lacZ,and a single HindIII site within tet^r.The EcoRI-HindIII cut plasmid is combined with a DNA fragment with compatible ends.Cells that contain the plasmid with the insert will be

A 16 kb linear DNA is cut with EcoRI and BamHI.The EcoRI digest yields fragments of 2,6,and 8 kb.The BamHI digest yields fragments of 5 and 11 kb.An EcoRI-BamHI double digest yields 2,3,5,and 6 kb fragments.The map of this DNA has

The restriction enzyme EcoRI cuts a linear 19 kb piece of DNA into fragments of 1,3,6,and 9 kb.How many EcoRI sites are there in the 19 kb piece of DNA?

What is the function of the amp^r gene in a vector?

cDNA libraries are generated using a reverse transcriptase and represent the population of RNA transcripts initially contained in the cells used.

It is possible for two perfectly matched 50 bp DNA sequences from two different species to have arisen by chance.

Which enzyme is used to generate DNA from RNA transcripts,for cDNA libraries?

When bacterial transformants containing a library are transferred to nitrocellulose filters and screened,one of the steps is treatment with an alkaline solution.What does this do?

Pseudogenes are evidence for

Restriction enzymes were named because they restrict

Where do restriction enzymes come from,and what is their normal physiological function?

The lacZ gene is sometimes included in a cloning vector.What does it encode?

List two reasons that partial digests are performed on genomic DNA when producing fragments for a library.

A 16 kb linear DNA is cut with EcoRI and BamHI.The EcoRI digest yields fragments of 2,6,and 8 kb.The BamHI digest yields fragments of 5 and 11 kb.An EcoRI-BamHI double digest yields 2,3,5,and 6 kb fragments.If the 3 kb fragment from the double digest is used as the probe in a Southern blot of the EcoRI digest,to which fragment(s)will it hybridize?

Which statements are true? i.In thalassemia,globin proteins are produced,but contain a point mutation. ii.In sickle-cell anaemia,globin proteins are produced,but contain a point mutation. iii.Sickle-cell anaemia is caused by a mutation in the β-globin gene. iv.Sickle cell anaemia is caused by a mutation in the α-globin gene.

Probability of a 6-base restriction enzyme site existing in a stretch of DNA is (1/6)⁴.

A genomic library is a

In gel electrophoresis of DNA,fragments move at different rates because they have different

PCR is used to

The genomic equivalent of a library is determined by multiplying the number of clones on a plate by the size of the average insert.