Ch 12 Bio
You run a PCR cycle for five cycles. Theoretically, how many copies of your sequence would you now have?
32
Failure to recover a specific band in a gel made after PCR can be attributed to:
All of the answer options are correct.
Which of the following is true regarding DNA replication?
Both strands get shortened at opposite ends during replication
Which of the following is needed to form recombinant DNA?
DNA ligase
Why are primers needed for DNA replication?
DNA polymerase can only add nucleotides to an existing chain, it cannot initiate synthesis of a new strand.
What is the difference between Sanger sequencing and PCR with regard to the materials needed to perform these reactions?
In Sanger sequencing, dideoxynucleotides are needed, but not in PCR.
Which of the following best describes Sanger sequencing?
Labeled dideoxynucleotides prevent the addition of another nucleotide after them. The resulting DNA fragments can then be run on a regular gel to determine the sequence.
Mitochondria contain their own DNA and replicate on their own. Why don't they suffer the same consequences as our cells in terms of limited division?
Mitochondrial DNA is circular, so it doesn't shorten when it replicates.
Which of the following statements about the strands of a newly replicated DNA molecule is correct?
One strand is new and the other is from the original molecule.
Why are telomeres a necessary component of linear chromosomes?
They extend the life of cells because DNA is shortened every time it is replicated
Why are single-stranded binding proteins necessary for DNA replication?
They prevent the two parental strands from coming together again.
Which of the following is considered a transgenic organism?
a rat with rabbit hemoglobin genes
Which of the following reasons explains why bacteria can continually divide?
because their DNA is circular so the DNA never shortens after replication
Restriction enzymes are an essential component of PCR.
false
True or false: DNA polymerase is the enzyme that separates the two strands of DNA during DNA replication.
false
True or false: One application of GMOs is to engineer mice that have particular diseases that scientists wish to study.
false
True or false: Recombinant DNA only occurs when you take DNA from another organism and insert it into a bacterium.
false
True or false: Telomerase activity in stem cells is very low.
false
True or false: The first step of PCR is called annealing.
false
True or false: The semiconservative model of DNA replication means that each DNA strand consists of some newly synthesized DNA and some parental DNA.
false
True or false: Transformation is the process where DNA is extracted from a plasmid.
false
What is the name of the enzyme that separates the two strands of DNA during replication?
helicase
Which of the following enzymes is responsible for joining Okazaki fragments together?
ligase
The point at which DNA synthesis is initiated is called the:
origin of replication
The extrachromosomal DNA found in bacteria is called a:
plasmid
Restriction enzymes:
recognize certain DNA sequences. Some of them will cut straight through; others will leave an overhang at both ends of the cut.
What is the name of the class of enzymes that recognizes a specific sequence of DNA and cuts it?
restriction endonucleases
Which of the following is not needed for DNA replication?
ribosomes
In gel electrophoresis, DNA fragments are separated based on their:
size
DNA sequencing using the Sanger method relies on:
the termination of DNA synthesis at specific bases
Which of the following do sticky ends and nucleic acid probes have in common?
they both involve complementary base pairing
What is the function of the enzyme DNA polymerase?
to synthesize a strand of DNA using DNA as a template
True or false: In order to produce a recombinant DNA molecule, restriction enzymes are first used to cut the DNA.
true
True or false: PCR is the name of the reaction used to amplify specific sequences of DNA.
true
True or false: Synthesis of nucleic acids always occurs in the 5' → 3' direction.
true
True or false: Telomerase is the name of the enzyme that replaces shortened telomeres.
true
