ch. 11 nucleic acid structure and DNA replication
DNA specimen with 30% guanine has
20% thymine
complement to DNA strand 5'-ATTCGGTGA-3'
3'-TAAGCCACT-5'
who discovered that DNA was the genetic material or transforming factor that could convert nonvirulent r-type streptococcus bacterium into the virulent s-type?
Avery, Macleod, and Mccarthy
which of the following would represent the "transformation principal" first proposed by Griffin through is studies on streptococcus bacterium?
DNA
molecule responsible for separating double stranded DNA into single strands
DNA helicase
not critical for DNA replication of the leading strand
DNA ligase
which does not belong: replication fork, single-stranded binding proteins, DNA ligase, topoisomerase, helicase
DNA ligase
protein not important for separating the DNA strands and allowing movement of the replication fork during DNA replication
DNA polymerase
produces short sequences of RNA, which allows polymerase to synthesize a new strand of DNA
DNA primase
functions of DNA polymerase
DNA synthesis, DNA proofreading, and removes RNA primers and fills in the gaps
most complex structure for genetic material
chromosome
pyrimidines
cytosine, thymine, uracil
a strand of DNA is composed of nucleotide bases, sulfate groups and sugars
false
if the sequence for one strand of DNA is 3'-TCGATT-5' then its complementary stand would have a sequence of 3'-AGCTAA-5'
false
if there is 28% adenine then there must be 28% cytosine for the DNA composition of a particular organism
false
studies by avery, macleod, and mccarthy with different strains of bacteria and those by hershey and chase with T2 bacteriophage determined that proteins are highly complex molecules that form the genetic material for bacteria and viruses
false
mismatched scientist-discovery
griffith-chromosomes
purine base forming 3 hydrogen bonds when binding to its complementary base
guanine
purines
guanine, thymine
where would one detect most of the DNA if a T2 bacteriophage were allowed to infect the bacteria?
inside the infected bacterium
incorrect statement about DNA replication
it is powered by the hydrolysis of ATP
molecule catalyzes covalent bond formation between fragments of DNA
ligase
where would one expect to find the most telomerase
male germ cells that give rise to gametes
simplest to most complex
nucleotide, DNA, gene, chromosome, genome
building blocks of dna
nucleotides
made in replication the lagging strand of DNA unlike the leading strand
okazaki fragments
DNA from bacteria grown in heavy medium and light medium and allowed to replicate for ONE generation are centrifuged to yield what type of gradient band(s)
one half-heavy (intermediate to heavy and light) band
DNA from bacteria grown in heavy medium and light medium and allowed to replicate for TWO generations are centrifuged to yield what type of gradient band(s)
one light and one half-heavy band
nucleotides of DNA are composed of
phosphate group, deoxyribose sugar, and nitrogenous base
DNA nucleotides combine to form what type of bond
phosphodiester
mechanism of DNA replication is
semiconservative
attaches DNA sequences at the ends of eukaryotic chromosomes
telomerase
incorrect statement about telomeres
telomeres would predominate more in cells of older than younger individuals
false statement about the structure and composition of DNA
the amount of thymine closely approximates that of guanine within a particular organism
which of the following is not a criterion for an organism's genetic material?
the genetic material must be dynamic, changing rapidly in response to changes in the environment
type s is lethal, nonlethal if heat inactivated. type r is nonvirulent. what would occur if r strain and killed s strain are injected into a host organism?
the r strain would be transformed into the virulent s strain and kill the host
why is there a need for okazaki fragments on lagging strand but not leading strand of DNA
the two parental strands of DNA are antiparellel and DNA polymerase makes DNA in the 5' to 3' direction only
mismatched protein-function
topoisomerase-separates double-stranded DNA into single strands
DNA helicase and topoisomerase are similar insofar as they promote the unwinding and coiling of DNA
true
DNA is a double helix structure whose stands are held together by hydrogen bonds with A to T and C to G base pairing
true
okazaki fragments are sequences of DNA most often found on the lagging strand of DNA during DNA replication
true
sulfur would be a better isotope than phosphate to track DNA synthesis
true
the progressive shortening of telomeres in DNA correlates with cell senescence
true
when considering the complexity of genetic material, multiple genes are found within a chromosome
true
one of the most critical pieces of evidence to the discovery of DNA structure (double helix)
x-ray diffraction pattern suggesting a double helix shape
how many replication forks at replication origin
2
what DNA sequence is produced from RNA sequence AUUGACGGU
TAACTGCCA
organism with the fewest origins of replications per cell
a rapidly dividing streptococcus
DNA polymerase
an enzyme that requires the presence of a double stranded nucleic acid primer to catalyze the addition of nucleotides to the 3' end of a growing DNA strand
false when comparing DNA and RNA
both are composed of identical nucleotides
true relationship about nucleotide composition of DNA?
c+a=g+t