Quiz 9

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

Sizes

What is the origin and physiological function of restriction endonucleases?

Bacteria produce them to protect against viral invasion

The purpose of the LacZ selectable marker found on plasmid vectors is to identify which colonies on a plate

Carry the insert DNA

For a ligation reaction to work, you will need to digest the vector with an enzyme that generates a 5' overhang and the insert with an enzyme that generates a 3' overhang

False

In agarose gel electrophoresis, DNA moves towards the negatively charged side of the gel chamber

False

Restriction enzymes create fragments of DNA by breaking hydrogen bonds

False

Restriction enzymes with a six base recognition sequence cut DNA more often than restriction enzymes with a four base recognition sequence

False

The sequence determined from the peaks of different colors in Sanger sequencing is the sequence of the template DNA strand

False

The steps of cloning insert DNA into a plasmid vector are transformation followed by ligation

False

What is the function of the ampr gene in a plasmid vector?

It allows a researcher to separate bacterial cells with a plasmid from those without a plasmid

Which of the following is NOT important to include in a vector when cloning fragments of DNA

Poly A tail

Which of the following restriction enzymes would you expect to cut genomic DNA most often

TaqI (4 base recognition sequence)

The recognition site for a restriction enzyme is 5′ ACCGG^T 3′. The ^ symbol indicates the site of cleavage. After digestion of DNA with this restriction enzyme, how will the ends of the resulting DNA fragments look?

They will have sticky, single-stranded ends with 5′ overhangs

What is the purpose of ethidium bromide in DNA electrophoresis?

To tag DNA fragments so they can be viewed under UV light

An antibiotic resistance gene found on a plasmid vector is an example of a selectable marker

True

In a gel electrophoresis, the DNA migrate toward the positive (+) end of the electrophoresis chamber

True

Sanger DNA sequencing requires both dNTPs and ddNTPs

True

1Which is an example of a recombinant DNA molecule?

a genomic fragment of human DNA ligated into a bacterial plasmid vector

In Sanger sequencing, what causes DNA synthesis to terminate at a specific base?

incorporation of a dideoxynucleotide that lacks a 3′ hydroxyl

Which is a step in hierarchical genome sequencing that is not found in shotgun genome sequencing

organize the clones based on their order in the genome

In Sanger sequencing, the role of the DNA polymerase is to

synthesize new DNA that is complementary to the template strand

The recognition site for a restriction enzyme is 5′ ACC^GGT 3′. The ^ symbol indicates the site of cleavage. After digestion of DNA with this restriction enzyme, how will the ends of the resulting DNA fragments look

they will have blunt ends

In a Sanger sequencing results, the color of each peak indicates which ddNTP was added to the DNA at that location

true