Chapter six, test two Flashcards
where does the nitrogenous base bond with on the sugar
1’ carbon
what phage did hershey and chase use
T2
what does the backbone of Z DNA look like
zigzag, irregular
the two chains of DNA wrap around each other once every how many BP
10
number of H bonds between A and T
2
function of replisome
help unwind dna with helicase to form leading and lagging strand
what was hershey and chase experiment
grew two types of T2 one with radioactive phosphorous and one with radioactive sulphur centrifuge the two together to see ghost made of protein was marked with sulphur and DNA marked with phosphorous
how can you get genetic info without unwinding DNA
some atoms on major and minor groove are exposed and provide chemical info
if overwinding happens during replication what is this called
supercoiling
how does B DNA spiral
to the right
new combination already existing alleles arise from two different types of meiotic events
independent assortment and crossing over
what in RNA is different from DNA
ribose sugar Uracil usually single stranded less stable
what are the two grooves created by the backbones
major and minor
who discovered the structure of DNA
watson and crick
what does bacterial genetic material look like
singular circular chromosome lies within cell with no nuclear membrane
what did avery, macleod and mccarty do in their experiment
find the chemical composition in the transforming principle
what is a nucleoside composed of
nitrogenous base and ribose sugar
where will you find ss DNA
viruses
what are the two template strands called
leading and lagging
what is conservative replication
one of the two daughter double helixes contains only the original DNA and the other helix is the newly synthesized strands
what does DNA polymerase 3 do
add nucleotides to 3’ end
what are the purines
adenosine and guanine
what makes an RNA primer
primase primosome protein complex
what is classified as a somatic mutation
mosaic cancer
why are s virus smooth
they synthesize a polysaccharide capsule
what must be present before DNA POL3
RNA primer
what does DNA pol 1 do
replace RNA primer of the okazaki fragment with DNA error correction
what are some sequence specific DNA binding proteins
transcription factors restriction enzymes
how can DNA polymerase enzymes catalyze the formation of a new phosphodiester bond
use energy released from severing the triphosphate arm of a dNTP substrate molecule
what is the only difference between nucleotides
nitrogenous bases
how can a DNA polynucleotide grow
adding a nucleotide to the 3 end of an existing polynucleotide
how does Z DNA spirla
to the left
what is semiconservative replication
the two daughter DNA has one strand from original and one strand that is brand new
what is a primer
a short, single stranded molecule of DNA or RNA a few nucleotides long that base pairs with part of the template strand
what is transformation
ability of a substance to change the genetic characteristics of an organism
why did researchers believe that proteins had greater potential for diversity and better suited for genetic material
made of 20 amino acids and not four nitrogenous bases
what is the feulgen reaction
chromosomes redden while other areas of cell remain uncolored shows DNA localized in chromosomes
two separated strands of DNA in replication represent
the templates
what kind of bond is a phosphodiester bond
covalent bond
why is the conservative and dispersed replication not very good
doesnt show how there should be a mechanism for copying the information in the sequence of bases
who created the X ray images of DNA
rosalind franklin
in eukaryotes, how many origin of replications
multiple
number of H bonds between G and C
3
who came up with the name nuclein
freidrich Miescher
what does helicase do
unwind DNA
how many carbon and nitrogen in pyrimidines
6
what is recombination
the generation of new allelic combinations through genetic exchange between homologous chromosomes
what are the three strict requirements for DNA polymerase action in DNA replication
four dNTPs ss template primer with a free 3’ hydroxyl group
what is the function of telomeres
ensure the maintenance and accurate replication of the two ends of each linear chromosome
how to find number of ways nucleotide sequences can occur
4^n n= number of nucleotides long
how are okazaki fragments added
using short RNA primers
in bacteria, how many origins of replication
one
what brought up the semiconservative model
watson and crick
what organisms carry RNA as their genetic material
retroviruses
how does the lagging strand form
okazaki fragments
what organisms have circular chromosomes
prokaryotes mitochondria and cholorplasts some viruses
what did Chargaff find about DNA
ratio between A and T and G and C are 1:1 bond together with a hydrogen bond
what is polymerization
DNA POL 3 catalyzeds the joining of a new nucleotide to the preceding nucleotide through formation of phosphodiester bonds
where does phosphate group bond with on the sugar
5’ carbon
B DNA a more occurring DNA
yes
phosphodiester bond, bonds what carbons together of sugars
3’ to 5’
what are the pyrimadines
thymine cytosine uracil
what is the transforming principle
substance searching for that is heritable
is a point mutation germinal or somatic
germinal
are DNA chains parallel or anti
anti
who extracted a weakly acidic phosphorous rich material from nuclei from WBC
Friedrich Miescher
what did avery look for in his experiments
the transforming principle
what does DNA ligase do
covalently joins successive okazaki fragments
what happens if chromosomes fail to recombine during prophase 1 and metaphase 1
cannot orient themselves towards opposite poles of meiosis 1 spindle causing nondisjunction
what is a nucleotide composed of
nitrogenous base ribose sugar phosphate group
do bacteria undergo meiosis or mitosis
no they go through binary fission
what bond is used to join nucleotides together
phosphdiester bonds
what is a point mutation
affect one or just a few base pairs in the DNA and thus alter only one gene at a time
does heat kill the Smooth virus
yes
who created the experiment that confirmed the semiconservative nature of DNA replication
Matthew Meselson and Franklin Stahl
what was the significance of griffith experiment with the s and r virus
dead virulent cells can still transfer DNA to living non virulent cells
what did Arthur Kornberg do
he isolated and purified components of the replication machinery put them in a tube and created new DNA
who did the smooth and rough virus with mice experiment
frederick griffith
what did rosalind franklin find
spiral shaped or helical spacing between repeating units is 3.4 A
what is the complete turn for the helix
34 A
what is the diameter of the DNA molecule
20 A
what keeps the DNA helicase open
single stranded DNA binding proteins
what do restriction enzymes do
cut DNA at particular sites
why do RNAs have a complicated structure
RNA folds on itself, making it a short double strand
how many carbon and nitrogen in purines
9
what are the two stages for DNA replication
initiation and elongation
how does DNA protect its own integrity
redundancy remarkable precision of cellular replication machinery enzymes that repair chemical damage to DNA
DNA to DNA process is called
replication
what is mutation rate
the probability with which a particular mutational event takes place per biological entity per reproductive cycle
what do transcription factors do
turn genes on and off
can DNA polymerase establish the first link in a new chain
no, it needs a primer
what is DNA nucleotide subunit made of
deoxyribose phosphate group nitrogenous base
DNA to RNA process is called
transcription
what does eukaryotic chromosomes look like
long, linear, double helixes
what helps with supercoiling
DNA topoisomerases
what is dispersive replication
both daughter double helix would carry blocks of original DNA interspersed with blocks of newly synthesized material
what is the reason for multiple origins of replication
ensure that copying is completed within the time alotted
where do the forks meet in bacteria
termination region
