chapter 12 Flashcards
Imagine that a doctor is culturing cells from a malignant melanoma and from a normal skin sample. How would you expect these two cell populations to differ?
Malignant melanoma cells would have active telomerases that constantly replenish and lengthen telomeres.
What is the function of the enzyme DNA polymerase?
to synthesize a strand of DNA using DNA as a template
Which of the following statements is not true regarding chromosome replication?
- During chromosome replication, multiple origins of replication form for all DNA in a cell.
- Replication bubbles remain distinct, isolated structures during chromosome replication and never fuse with one another.
- In humans, it takes several days to replicate an entire chromosome.
- During chromosome replication, only linear DNA within eukaryotic cells is copied.
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.
What is the name of the class of enzymes that recognizes a specific sequence of DNA and cuts it?
restriction enzymes
_______ requires both a template and an appropriately placed DNA 3’ end to synthesize a nucleic acid.
DNA polymerase
Which of the following reasons explains why bacteria can continually divide?
because their DNA is circular so the DNA never shortens after replication
_______ moves outward from the origin of replication and breaks hydrogen bonds between DNA nucleotides.
Helicase
What is the benefit of using Taq polymerase in PCR?
Because it is taken from bacteria that lives in high temperatures, it does not denature and more DNA polymerase does not have to be added after every cycle.
________ is the first enzyme to synthesize a nucleic acid at a replication fork.
RNA primase
Which of the following statements are true regarding telomeres?
Telomeres can contain repeated base sequences
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
DNA sequencing using the Sanger method relies on
the termination of DNA synthesis at specific bases
Why are single-stranded binding proteins necessary for DNA replication?
They prevent the two parental strands from coming together again.
Energy is required in order to add a nucleotide to the growing strand of DNA during replication. From where does that energy come?
the incoming nucleotide
A Southern blot is a technique that relies on
hybridization of DNA sequences to complementary DNA sequences
During PCR, where does the energy come from that adds the nucleotide to the growing DNA strand?
the incoming nucleotides
The first step of PCR is called annealing
false (denaturation)
During DNA replication, the leading strand contains Okazaki fragments.
false : lagging strand contains okazaki
RNA is involved in which of the following cellular processes?
DNA replication, transcription, and translation
What procedure is typically used after PCR is complete to make sure the amplification process worked properly
gel electrophoresis
The following enzymes play important roles in DNA replication:
DNA polymerase
Primase
Ligase
Helicase
In what order do they work during replication?
Helicase, primase, DNA polymerase, ligase
_________ relieves the tension on the double helix during DNA replication.
Topoisomerase
