List the three characteristics that early scientists knew genes must posess.
ability to store information
information must stable enough to pass on
information must be able to mutate
If genetic information was not stable it would ______ over time.
degrade
True or False - Genetic mutations provide for genetic variability and are essential for evolution.
True
List the two acid components that were found as part of the genetic material.
ribonucleic acid
deoxyribonucleic acid
Who performed important research with Streptococcus pneumoniae?
Griffith
What bacteria strain did Griffith use in his bacterial transformation experiments?
Streptococcus pneumoniae
What two strains of Streptococcus pneumoniae did Griffith find?
The S strain and the R strain
Which strain of streptococcus has a capsule, S or R?
the S strain
The R strain of Streptococcus pneumoniae has what sort of exterior characteristic, smooth or rough?
rough
The main difference between the R strain and the S strain is the absence of a:
capsule
What happened to the mice injected with S strain strep?
they died
What happened to mice injected with R strain strep?
they lived
True of False - The S strain of streptococcus is pathogenic while the R strain is not.
True
What happened to the mice injected with "heat-killed" S strain strep?
they lived
What happened to mice injected with "heat-killed" S and R strain strep?
they died
A change in genetic makeup due to the assimilation of foreign DNA is known as:
transformation
List the four nucleotides found in DNA.
adenine
guanine
thymine
cytosine
Which nucleotides are purines?
adenine
guanine
Which nucleotides are pyrimadines?
thymine
cytosine
How were nucleotides originally thought to pair up?
like bases would pair
What would happen if two purines paired up?
they would be too long for the DNA ladder
If two pyrimadines paired they would be too ____ for the DNA ladder.
short
A purine is ________ than a pyrimadine.
larger
How do nucleotides actually pair up?
purine + pyrimadine
What are Chargaff's Rules?
The total amount of each nucleotide will vary between organisms
In a specific organism, the amount of A=T, and the amount of C=G
Do humans have more A/T pairs or C/G pairs?
A/T pairs
Who first constructed the DNA double helix model?
Watson and Crick
What sugar is part of the DNA backbone?
deoxyribose
What basic shape is deoxyribose?
a pentagon
The backbone of DNA is comprised of what two molecules?
deoxyribose and phosphate
Deoxyribose is a ______ carbon sugar.
five
How are the carbons in deoxyribose numbered?
clockwise
At which carbon of deoxyribose will the phosphate attach?
5' carbon
How does one sugar-phospate attach to the next sugar-phosphate?
phosphate bonds covalently with the 3' carbon of the next sugar
The orientation of DNA strands is:
anti-parallel
The nucleotide base pairs attach to which carbon of deoxyribose?
the 1' carbon
What type of bond connects complimentary nucleotide bases?
hydrogen bonds
Because the parent strand of DNA separates and acts as a template for the daughter strand, DNA replication is said to be:
semi-conservative
What is an origin of replication?
starting point for replication
How many origins will a eukaryotic chromosome have?
several
As the DNA strands pull apart from the origin, they form:
replication bubbles
The point at which the DNA strand is pulling apart as replication moves outward is known as the:
replication fork
What enzyme unwinds DNA?
helicase
The molecule that binds to, and keeps the DNA strands separated after helicase unzips them is:
the single strand binding protein
What is the role of topoisomerase?
moves ahead of helicase, breaking hydrogen bonds and relieving tension in the strand
True or False - Hydrogen bonds remain broken after topoisomerase breaks them.
False - they reform and hold until helicase breaks them again
What is needed in order for DNA replication to start?
a primer
What is the function of primase?
to manufacture the short RNA primer
The RNA primer needed to start DNA replication is produced by:
primase
Where the RNA primer attaches becomes the _____ prime end of the daughter strand.
five
DNA poly III can only add nucleotides to which end of the daughter strand?
the 3' end
A new DNA strand always forms in which direction?
5' to 3'
The 5' to 3' parent strand is known as the:
leading strand
The 3' to 5' parent strand is known as the:
lagging strand
The strand that replicates continuously towards the replication fork is the:
leading strand
The strand the replicates away from the replication fork in a series of fragments is the:
lagging strand
What are the three steps of leading strand replication?
DNA polymerase III attaches the appropriate nucleotides
DNA polymerase I strips off the RNA primer and replaces it with DNA nucleotides
DNA ligase fills in phosphates, connecting the DNA backbone where primers were removed
True or False - When the lagging strand fragment reaches an RNA primer, the DNA poly III will detach and move backwards past the previous primer and start a new fragment.
True
What enzyme adds nucleotides to the new DNA strand?
DNA polymerase III
What enzyme will fill in the blanks after the primers are removed?
DNA polymerase I
After the primers are removed and replaced with DNA nucleotides what enzyme will add phosphates and connect the DNA backbone?
DNA ligase
The small fragments of nucleotides created in the 5' to 3' order on the lagging strand are known as:
Okazaki fragments
At the ends of chromosomes are sequences of genetic nonsense called:
telomeres
Because DNA poly III cannot add nucleotides to the 5' end of a strand, this enzyme adds telomeres to the ends of DNA strands which can be clipped off.
telomerase
What enzyme proofreads and removes any incorrect nucleotides from a DNA strand?
nuclease
What two things happen when an error is found in the replicated DNA strand?
