Exam 15: Analysis of Gene Function by Forward Genetics and Reverse Genetics

The ends left by some restriction enzymes that do not have 5' or 3' overhangs are called what?

Efficient production of eukaryotic proteins in E. coli may require all of the following except?

In using Agrobacterium tumefaciens to transfer genes into plants, what is transferred from bacterium to plant?

In the 1990s, gene therapy was seen as a probable cure for many genetic diseases. List three or four reasons that it has so far been of limited success.

In the pUC plasmids, a polylinker region that includes multiple restriction sites is embedded in the lacZ component. If a sequence of interest is inserted into this region, what is the effect on lacZ?

If recombination results in random integration of a DNA sequence so that it produces a non- homologous region, the recombination is __________.

The human genome is 3 × 10⁹ bp in length. Calculate how many fragments would result from the complete digestion of the human genome with EcoRI (5'- G˙AATTC- 3').

Your student is trying to create a "Gene X" knockout mouse by introducing a recombinant construct into embryonic stem (ES) cells, selecting transformants, and introducing the transformed cells into mouse blastocysts. He designed his construct as follows: NeoR---- region of homology to Gene X--- HSV tk- -- region of homology to Gene X where NeoR is the neomycin- resistance gene and HSV tk is the Herpes Simplex virus thymidine kinase gene. He transforms the ES cells and exposes them to G418 and ganciclovir. Explain to your student he failed to recover transformed ES cells.

To ensure that a human gene is translated properly in a bacterial cell, what should you clone instead of the genomic DNA fragment that contains the gene?

A hypothetical restriction sequence is 5'- TCTAGA- 3'. The palindromic sequence is 3'-_________ - 5'.

By what method is T- DNA integrated into the plant genome?

If a gene is replaced with a heterologous sequence such that the gene is then nonfunctional, what is the result usually called?

Agrobacterium tumefaciens is often used in the production of transgenic plants because of its Ti plasmid. This plasmid is usually "disarmed" by deleting its tumor genes along with the genes for producing what products that would have been advantageous to the bacterium?

Suppose a gene from a cow is introduced into a frog. This results in a_________ transgene.

Assume that a plasmid is 4000 base pairs in length and has restriction sites at the following locations: 600, 1000, 2200, and 3800. Give the expected sizes of the restriction fragments following complete digestion.

What are the short single- stranded overhangs created by cleavage of DNA by specific restriction enzymes?

Which of the following statements is FALSE regarding gene therapy?

In producing an E. coli plasmid to be an expression vector, an experimenter includes genes for selectable markers and a promoter for the expression of the introduced genes. She uses a cDNA sequence to ensure the insert contains no introns. The gene inserted is transcribed, but not translated. What sequence did she omit from the plasmid?

Genetic therapy for mice with Duchenne muscular dystrophy demonstrated that which method could be used to delete a mutant exon of the dystrophin gene in muscle cells?

In a cDNA library, not all expressed genes will be represented. On what does this depend?