Chapter 13 QUESTION REVIEW Flashcards
Griffth’s experiments with s. pnuemisiae were significant because the showed that traits could be transferred from one organism to another. What else did he find that was significant?
The transferred traits were heritable to future generations
In the Hershey-Chase Experiment that helped confirm DNA, not proteins, was the hereditary material, what was the key finding? (how did they prove this to be the case?)
Radioactively labelled phosphorus was present inside the infect bacteria, which was the tag placed on virus’s DNA
Who conducted the x-ray diffraction studies that were key to the discovery of the structure of DNA?
Rosalind Franklin
DNA replication is said to be semiconservative; what does this mean?
Each new double helix consists of one old and one new strand of DNA
Short segments of newly synthesized DNA are joined into a continuous strand by _________
ligase
The first step in the replication of DNA is catalyzed by ___________
helicase
The action of helicase creates __________
replication forks and replication bubbles
Why is the new DNA complementary to the 3’ to 5’ strands assembled in short segments?
DNA polymerase can only assemble DNA in the 5’ to 3’ dirrection
The synthesis of a new stand begins with the synthesis of a ___________
RNA primer complementary to a pre-existing DNA strand
What is responsible for catalyzing the formation of a RNA primer
primase
What is the role of DNA polymerase during DNA synthesis?
DNA polymerase is the enzyme that catalyzes the addition of a nucleotide onto the 3’ end of a growing DNA strand
What is present at the 3’ end of a growing DNA strand? The 5’ end?
3’ end: hydroxyl
5’ end: phosphate group
What provides the E to drive the addition of a nucleotide onto a DNA ?
The release of pyrophosphate from the incoming nucleotide, and the hydrolysis of the pyrophosphate to inorganic phosphate
What materials does DNA polymerase require in order to synthesize a complete strand of DNA?
1) single-stranded DNA template
2) all 4 deoxyribonucleotides triphosphates
3) 3’ -OH end of new DNA strand
What process repairs damage to a preexisting double helix?
nucleotide excision repair
What are the repetitive DNA sequences present at the ends of eukaryotic chromosomes called?
telomeres
What are chromosomes made of?
DNA and protein
what functions in the regulation of gene expression?
euchromatin
In recominate DNA experiments, what is used to cut pieces of DNA, and what joints the resulting fragments to form recombate DNA?
a restriction enzyme … DNA ligase
Gel electrophoresis separates DNA fragments on the basis of what characteristics?
length (shape and size)
Archaeologist unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human’s genes?
Use of the polymerase chain rxn
