MBG Final questions well answered to
pass
What is the central dogma of molecular biology? - correct answer ✔✔Replication->DNA-
>Transcription->RNA->translation->protein
What are characteristics of DNA replication? - correct answer ✔✔-very accurate (very low error
rate)
-Very rapid
What is the structure of DNA? - correct answer ✔✔• Complementary base pairs (A pairs with T,
G pairs with C)
• Three hydrogen bonds pair G with C, while two hydrogen bonds pair A with T
• Anti-parallel 5' to 3' DNA strands
• Right-handed double helix (B-
DNA): most common form in living
cells
• Ten base pairs per turn
• 0.34 nm between stacked bases;
3.4 nm per helical turn
,What are the 3 theories of DNA replication? - correct answer ✔✔Conservative replication,
dispersive replication, semiconservative replication
What does it mean that DNA replication is semi-conservative? - correct answer ✔✔-after one
round of DNA replication, each DNA contains 1 parental and 1
newly-synthesized strand
- 1 template stand
What is dispersive and conservative replication? - correct answer ✔✔Not correct!!
What are the 3 modes of DNA replication? - correct answer ✔✔1. Theta replication
2. Rolling circle replication
3. Linear chromosome replication
What is theta replication? - correct answer ✔✔Prokaryotic DNA
replication that occurs in most circular DNA (eg., bacteria with only 1 origin of replication that is
4.6 million nt in length)
DNA replication is bidirectional
- 2 templates
1 origin of replication that is AT rich - less H bonds therefore is easier to break apart
1. Double stranded DNA unwinds at the origin of replication
,2. Producing single standed templates for the symthesis of new DNA. A replication bubble forms
with a replication fork at each end.
Result is 2 circular daughter DNAs
What is Rolling circle replication? - correct answer ✔✔Viruses and plasmids
Specialized form of replication that occurs in the F factor and some viruses (only 1 origin of
replication)
DNA replication is unidirectional
- 1 template
1. Replication is initiated by a break in one of the nucleotide strands (not AT rich site)
2. DNA synthesis begins at the 3' end of the broken strand - the inner strand is used as a
template. The 5' end of the broken strand is displaced
3. Cleavage releases a single-stranded linear DNA and a double stranded circular DNA
(this cycle may be repeated)
4. The linear DNA may circularize and serve as a template for synthesis of a complementary
strand.
The products are multiple circular DNA molecules
*ONLY HAS A LEADING STRAND - no lagging*
What is Linear chromosome replication? - correct answer ✔✔Eukaryotic cells
, occurs in the linear chromosomes of eukaryotic cells.
DNA replication is bidirectional
- 2 templates
They aren't sure if the origin is AT rich or not
1. Each chromosome contains numerous origins
2. At each origin, the DNA unwinds, producing a replication bubble
3. DNA synthesis takes place on both strands at each end of the bubble as the replication forks
proceed outward
4. Eventually, the forks of adjacent bubbles run into each other and the segments of DNA fuse
producing two identical linear DNA molecules
Results in two linear DNA molecules
What does DNA replication require? - correct answer ✔✔• DNA dependent DNA polymerase
• Four deoxyribonucleoside triphosphates (dNTPs)
A, T, C, G
• A single stranded template of DNA to be copied
• An RNA primer (provides the 3'-OH end to initiate DNA synthesis by DNA
polymerase)
pass
What is the central dogma of molecular biology? - correct answer ✔✔Replication->DNA-
>Transcription->RNA->translation->protein
What are characteristics of DNA replication? - correct answer ✔✔-very accurate (very low error
rate)
-Very rapid
What is the structure of DNA? - correct answer ✔✔• Complementary base pairs (A pairs with T,
G pairs with C)
• Three hydrogen bonds pair G with C, while two hydrogen bonds pair A with T
• Anti-parallel 5' to 3' DNA strands
• Right-handed double helix (B-
DNA): most common form in living
cells
• Ten base pairs per turn
• 0.34 nm between stacked bases;
3.4 nm per helical turn
,What are the 3 theories of DNA replication? - correct answer ✔✔Conservative replication,
dispersive replication, semiconservative replication
What does it mean that DNA replication is semi-conservative? - correct answer ✔✔-after one
round of DNA replication, each DNA contains 1 parental and 1
newly-synthesized strand
- 1 template stand
What is dispersive and conservative replication? - correct answer ✔✔Not correct!!
What are the 3 modes of DNA replication? - correct answer ✔✔1. Theta replication
2. Rolling circle replication
3. Linear chromosome replication
What is theta replication? - correct answer ✔✔Prokaryotic DNA
replication that occurs in most circular DNA (eg., bacteria with only 1 origin of replication that is
4.6 million nt in length)
DNA replication is bidirectional
- 2 templates
1 origin of replication that is AT rich - less H bonds therefore is easier to break apart
1. Double stranded DNA unwinds at the origin of replication
,2. Producing single standed templates for the symthesis of new DNA. A replication bubble forms
with a replication fork at each end.
Result is 2 circular daughter DNAs
What is Rolling circle replication? - correct answer ✔✔Viruses and plasmids
Specialized form of replication that occurs in the F factor and some viruses (only 1 origin of
replication)
DNA replication is unidirectional
- 1 template
1. Replication is initiated by a break in one of the nucleotide strands (not AT rich site)
2. DNA synthesis begins at the 3' end of the broken strand - the inner strand is used as a
template. The 5' end of the broken strand is displaced
3. Cleavage releases a single-stranded linear DNA and a double stranded circular DNA
(this cycle may be repeated)
4. The linear DNA may circularize and serve as a template for synthesis of a complementary
strand.
The products are multiple circular DNA molecules
*ONLY HAS A LEADING STRAND - no lagging*
What is Linear chromosome replication? - correct answer ✔✔Eukaryotic cells
, occurs in the linear chromosomes of eukaryotic cells.
DNA replication is bidirectional
- 2 templates
They aren't sure if the origin is AT rich or not
1. Each chromosome contains numerous origins
2. At each origin, the DNA unwinds, producing a replication bubble
3. DNA synthesis takes place on both strands at each end of the bubble as the replication forks
proceed outward
4. Eventually, the forks of adjacent bubbles run into each other and the segments of DNA fuse
producing two identical linear DNA molecules
Results in two linear DNA molecules
What does DNA replication require? - correct answer ✔✔• DNA dependent DNA polymerase
• Four deoxyribonucleoside triphosphates (dNTPs)
A, T, C, G
• A single stranded template of DNA to be copied
• An RNA primer (provides the 3'-OH end to initiate DNA synthesis by DNA
polymerase)
