Chapter 14 Study Notes Flashcards
Griffith performed experiments, which demonstrated
transformation in bacteria.
X-ray diffraction was used to determine that the diameter of a DNA molecule is ______
2 nm
Griffith’s experiments were important because they showed
that the genetic material could be passed from one cell to another
In their experiments, Avery, MacLeod, and McCarty isolated a substance, which had a transforming activity. Which of the following destroyed that substance’s ability to transform bacterial cells?
DNA digesting enzymes
The experiments with radioactively labeled phage that showed that DNA was the genetic material were performed by
Hershey and Chase
List components of a nucleotide:
phosphate group
nitrogenous base
sugar
Franklin used x-ray _____ to suggest that DNA has a helical structure.
diffraction
The DNA backbone is composed of
phosphate groups.
sugars.
Characteristics of the transforming substance isolated by Avery, MacLeod and McCarty.
RNA-digesting enzymes did not affect its transforming ability.
Protein-digesting enzymes did not affect its transforming ability.
DNA-digesting enzymes destroyed its transforming ability.
The elemental composition of the substance was very similar to that of DNA.
DNA’s phosphodiester _____ is composed of sugars and phosphates.
backbone
The DNA structure proposed by Watson and Crick involves
a sugar phosphate backbone
a helical structure
two grooves (major and minor)
DNA replication that leads to the production of double helices with one parental strand and one newly synthesized strand is consistent with
semiconservative replication
Of the following list, which 3 items are required for DNA replication
nucleotides
template
polymerase
During DNA replication _______ strand is synthesized continuously while the ________ strand is synthesized as small fragments that are connected to each other to form a continuous strand.
Leading
Lagging
Features of the Watson and Crick model include:
a helical structure
a sugar phosphate backbone
a double stranded structure
DNA replication in eukaryotic cells is complicated by the fact that eukaryotic cells have
linear chromosomes
When the double stranded DNA helix is unwound, two single strands of DNA are formed. These strands have to be stabilized because their hydrophobic bases are exposed to water. The proteins that stabilize the two single strands are called
single-strand binding proteins
Which types of cells have more than one origin of replication?
Eukaryotes
The enzyme that relieves DNA supercoiling ahead of the replication fork is
DNA gyrase
The function of telomeres is to
protect the end of chromosomes
