MEHARI BIOL 3200-FINAL EXAM UPDATED
ACTUAL EXAM QUESTIONS AND CORRECT
ANSWERS.200
If a gene operates in tandem with other genes, what is the unit called? -
<<<<CORRECT ANSWERS>>>An operon
What are the two kinds of extrachromosomal DNA that interact with bacterial genomes?
- <<<<CORRECT ANSWERS>>>Plasmids and bacteriophages (Plasmids carry info
that contributes to physiology fo the cell)
What are nucleoid loops anchored to? - <<<<CORRECT ANSWERS>>>Histone like
proteins (HU and H-NS)
How many loops does the E Coli nucleoid contain? - <<<<CORRECT
ANSWERS>>>Between 30-100
Positive supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Overwound
Negative supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Underwound
Most DNA in nature is (over or underwound) - <<<<CORRECT
ANSWERS>>>underwound - negative supercoils (some archaea in acid or high temps
is positively supercoiled)
What introduces supercoils in bacterial DNA? - <<<<CORRECT
ANSWERS>>>Topoisomerases
What is - made of a single protein, cleaves ONE strand of DNA, and results in relaxed
or underwound DNA supercoils? - <<<<CORRECT ANSWERS>>>Topoisomerase I
What is made of two subunits, introduces NEGATIVE supercoils, and is involved in
replication and transcription? - <<<<CORRECT ANSWERS>>>Topoisomerase II (Aka
DNA Gyrase, has GyrA and GyrB subunits)
How can a supercoil be introduced? - <<<<CORRECT ANSWERS>>>Cleave one
strand (Topo I) or cleave both strands (Topo II)
,What are the portions of noncoding DNA in eukaryotic genomes called? -
<<<<CORRECT ANSWERS>>>Introns and pseudogenes
What are the similarities of prokaryotic genomes and archaeal genomes? -
<<<<CORRECT ANSWERS>>>Both have...
- Polygenic operons
- Cells lacking a nuclear membrane
- A single circular chromosome
What are the differences of prokaryotic genomes and archaeal genomes? -
<<<<CORRECT ANSWERS>>>DNA replication, transcription, and translation
mechanisms are different (archaea closely resemble eukaryotic cells)
When one says DNA replication is semi-conservative and bidirectional, what does that
mean? - <<<<CORRECT ANSWERS>>>Semiconservative meaning daughter cell
receives one parental and one newly synthesized DNA strand.
Bidirectional meaning that it starts in one fixed origin and progresses in opposite
directions.
What is the initiator protein in Escherichia coli? - <<<<CORRECT ANSWERS>>>DnaA
How does DnaA trigger initiation of replication? - <<<<CORRECT ANSWERS>>>DnaA-
ATP complex binds to 9-mer repeats upstream of the origin. Binding causes DNA to
loop in preparation for opening (melting).
Where does replication begin? - <<<<CORRECT ANSWERS>>>OriC at DNA, forming
replication bubble.
What is the central dogma? - <<<<CORRECT ANSWERS>>>The 'Central Dogma' is
the process by which the instructions in are converted into a functional product. It was
first proposed in 1958 by Francis Crick, discoverer of the structure of DNA.
What did Frederick Griffith study in 1928? - <<<<CORRECT ANSWERS>>>Griffith
studied Streptococcus pneumoniae, a bacterium that causes pneumonia in mammals.
He found that one strain was harmless and one was pathogenic, mixed strains and
mouse died - DISCOVERED TRANSFORMATION
, What did Chargaff discover in 1947? - <<<<CORRECT ANSWERS>>>In all organisms,
the number of adenines is approximately equal to the number of thymines and the
number of guanines is approximately equal to the number of cytosines.
What did Watson, Crick, Wilkins, and Franklin discover? - <<<<CORRECT
ANSWERS>>>DNA is a double helix
Two sugar phosphate backbones are anti-parallel
A binds to T
C binds to G
How big is are prokaryotic genomes typically? - <<<<CORRECT ANSWERS>>>130-
14,000 kilo base pairs
How big are eukaryotic genomes typically? - <<<<CORRECT ANSWERS>>>2,400 to
100 million kilo base pairs
What is the functional unit of heredity? - <<<<CORRECT ANSWERS>>>The gene
If a gene operates in tandem with other genes, what is the unit called? -
<<<<CORRECT ANSWERS>>>An operon
What are the two kinds of extrachromosomal DNA that interact with bacterial genomes?
- <<<<CORRECT ANSWERS>>>Plasmids and bacteriophages (Plasmids carry info
that contributes to physiology fo the cell)
What are nucleoid loops anchored to? - <<<<CORRECT ANSWERS>>>Histone like
proteins (HU and H-NS)
How many loops does the E Coli nucleoid contain? - <<<<CORRECT
ANSWERS>>>Between 30-100
Positive supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Overwound
Negative supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Underwound
Most DNA in nature is (over or underwound) - <<<<CORRECT
ANSWERS>>>underwound - negative supercoils (some archaea in acid or high temps
is positively supercoiled)
What introduces supercoils in bacterial DNA? - <<<<CORRECT
ANSWERS>>>Topoisomerases
What is - made of a single protein, cleaves ONE strand of DNA, and results in relaxed
or underwound DNA supercoils? - <<<<CORRECT ANSWERS>>>Topoisomerase I
ACTUAL EXAM QUESTIONS AND CORRECT
ANSWERS.200
If a gene operates in tandem with other genes, what is the unit called? -
<<<<CORRECT ANSWERS>>>An operon
What are the two kinds of extrachromosomal DNA that interact with bacterial genomes?
- <<<<CORRECT ANSWERS>>>Plasmids and bacteriophages (Plasmids carry info
that contributes to physiology fo the cell)
What are nucleoid loops anchored to? - <<<<CORRECT ANSWERS>>>Histone like
proteins (HU and H-NS)
How many loops does the E Coli nucleoid contain? - <<<<CORRECT
ANSWERS>>>Between 30-100
Positive supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Overwound
Negative supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Underwound
Most DNA in nature is (over or underwound) - <<<<CORRECT
ANSWERS>>>underwound - negative supercoils (some archaea in acid or high temps
is positively supercoiled)
What introduces supercoils in bacterial DNA? - <<<<CORRECT
ANSWERS>>>Topoisomerases
What is - made of a single protein, cleaves ONE strand of DNA, and results in relaxed
or underwound DNA supercoils? - <<<<CORRECT ANSWERS>>>Topoisomerase I
What is made of two subunits, introduces NEGATIVE supercoils, and is involved in
replication and transcription? - <<<<CORRECT ANSWERS>>>Topoisomerase II (Aka
DNA Gyrase, has GyrA and GyrB subunits)
How can a supercoil be introduced? - <<<<CORRECT ANSWERS>>>Cleave one
strand (Topo I) or cleave both strands (Topo II)
,What are the portions of noncoding DNA in eukaryotic genomes called? -
<<<<CORRECT ANSWERS>>>Introns and pseudogenes
What are the similarities of prokaryotic genomes and archaeal genomes? -
<<<<CORRECT ANSWERS>>>Both have...
- Polygenic operons
- Cells lacking a nuclear membrane
- A single circular chromosome
What are the differences of prokaryotic genomes and archaeal genomes? -
<<<<CORRECT ANSWERS>>>DNA replication, transcription, and translation
mechanisms are different (archaea closely resemble eukaryotic cells)
When one says DNA replication is semi-conservative and bidirectional, what does that
mean? - <<<<CORRECT ANSWERS>>>Semiconservative meaning daughter cell
receives one parental and one newly synthesized DNA strand.
Bidirectional meaning that it starts in one fixed origin and progresses in opposite
directions.
What is the initiator protein in Escherichia coli? - <<<<CORRECT ANSWERS>>>DnaA
How does DnaA trigger initiation of replication? - <<<<CORRECT ANSWERS>>>DnaA-
ATP complex binds to 9-mer repeats upstream of the origin. Binding causes DNA to
loop in preparation for opening (melting).
Where does replication begin? - <<<<CORRECT ANSWERS>>>OriC at DNA, forming
replication bubble.
What is the central dogma? - <<<<CORRECT ANSWERS>>>The 'Central Dogma' is
the process by which the instructions in are converted into a functional product. It was
first proposed in 1958 by Francis Crick, discoverer of the structure of DNA.
What did Frederick Griffith study in 1928? - <<<<CORRECT ANSWERS>>>Griffith
studied Streptococcus pneumoniae, a bacterium that causes pneumonia in mammals.
He found that one strain was harmless and one was pathogenic, mixed strains and
mouse died - DISCOVERED TRANSFORMATION
, What did Chargaff discover in 1947? - <<<<CORRECT ANSWERS>>>In all organisms,
the number of adenines is approximately equal to the number of thymines and the
number of guanines is approximately equal to the number of cytosines.
What did Watson, Crick, Wilkins, and Franklin discover? - <<<<CORRECT
ANSWERS>>>DNA is a double helix
Two sugar phosphate backbones are anti-parallel
A binds to T
C binds to G
How big is are prokaryotic genomes typically? - <<<<CORRECT ANSWERS>>>130-
14,000 kilo base pairs
How big are eukaryotic genomes typically? - <<<<CORRECT ANSWERS>>>2,400 to
100 million kilo base pairs
What is the functional unit of heredity? - <<<<CORRECT ANSWERS>>>The gene
If a gene operates in tandem with other genes, what is the unit called? -
<<<<CORRECT ANSWERS>>>An operon
What are the two kinds of extrachromosomal DNA that interact with bacterial genomes?
- <<<<CORRECT ANSWERS>>>Plasmids and bacteriophages (Plasmids carry info
that contributes to physiology fo the cell)
What are nucleoid loops anchored to? - <<<<CORRECT ANSWERS>>>Histone like
proteins (HU and H-NS)
How many loops does the E Coli nucleoid contain? - <<<<CORRECT
ANSWERS>>>Between 30-100
Positive supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Overwound
Negative supercoils... DNA is (over or underwound) - <<<<CORRECT
ANSWERS>>>Underwound
Most DNA in nature is (over or underwound) - <<<<CORRECT
ANSWERS>>>underwound - negative supercoils (some archaea in acid or high temps
is positively supercoiled)
What introduces supercoils in bacterial DNA? - <<<<CORRECT
ANSWERS>>>Topoisomerases
What is - made of a single protein, cleaves ONE strand of DNA, and results in relaxed
or underwound DNA supercoils? - <<<<CORRECT ANSWERS>>>Topoisomerase I
