Molecular Biology Exam test quiz
and answers graded A+
The process of ------ in eukaryotic cells is analogous to bacterial transformation.
a. Transfection
b. Transcription
c. Transition
d. Translation
e. Translocation - ANS✅✅A. Transfection
Hersehy and Chase tracked DNA during phage infection using a radioisotope of:
a. oxygen
b. sulfur
c. nitrogen
d. phosphorus
e. carbon - ANS✅✅d. phosphorus
Mutations that have no apparent effect are called:
a. silent mutations
b. loss-of-function mutations
c. null mutations
d. leaky mutations
e. gain-of-function mutations - ANS✅✅a. silent mutations
If the mole % of A residues in double-stranded DNA is 29%, what would the mole % of G residues
be? - ANS✅✅21%
, Meselson and Stahl used density labeling of DNA to show that DNA replication occurs via a
semiconservative mechanism. If DNA is isolated and separated by density, how many bands would
be observed and how would their density compare with the starting DNA? The DNA would yield two
different density bands. - ANS✅✅Two of the daughters would contain one original heavy parental
strand and one light daughter strand (hybrid density), and two of the daughters would contain two
light strands (light density)
G-C content of one of them is 32% and the G-C content of the other is 62%. One of the organisms
lived deep in the ocean at temperatures around 10 C and the other was isolated from the mojave
desert, where temps reached 45 C - ANS✅✅Mojave desert is likely to have a G-C content of 62%
and the ocean bacteria is likely to have a G-C content of 32%. Organisms that thrive at elevated
temperatures have genomes with a higher fraction of G-C base pairs to stabilize the double helical
structure of their DNA
Which of the following is not a good feature of a plasmid vector?
a. multiple cloning site
b. telomeres
c. antibiotic resistance gene
d. origin of replication
e. blue/white selection system - ANS✅✅b. telomeres
during meiosis, genes that are on opposite ends of a long eukaryotic chromosome:
a. never recombine
b. show less than 50% recombination
c. show exactly 50% recombination
d. show between 50% and 100% recombination
e. show 100% recombination - ANS✅✅c. show exactly 50% recombination
The process of RNA transcription generates an RNA copy of one of the strands of DNA that may then
translated into polypeptide by ribosomes in the cytoplasm. Do all genes encode polypeptides? -
ANS✅✅No. some encode RNA such as rRNA
and answers graded A+
The process of ------ in eukaryotic cells is analogous to bacterial transformation.
a. Transfection
b. Transcription
c. Transition
d. Translation
e. Translocation - ANS✅✅A. Transfection
Hersehy and Chase tracked DNA during phage infection using a radioisotope of:
a. oxygen
b. sulfur
c. nitrogen
d. phosphorus
e. carbon - ANS✅✅d. phosphorus
Mutations that have no apparent effect are called:
a. silent mutations
b. loss-of-function mutations
c. null mutations
d. leaky mutations
e. gain-of-function mutations - ANS✅✅a. silent mutations
If the mole % of A residues in double-stranded DNA is 29%, what would the mole % of G residues
be? - ANS✅✅21%
, Meselson and Stahl used density labeling of DNA to show that DNA replication occurs via a
semiconservative mechanism. If DNA is isolated and separated by density, how many bands would
be observed and how would their density compare with the starting DNA? The DNA would yield two
different density bands. - ANS✅✅Two of the daughters would contain one original heavy parental
strand and one light daughter strand (hybrid density), and two of the daughters would contain two
light strands (light density)
G-C content of one of them is 32% and the G-C content of the other is 62%. One of the organisms
lived deep in the ocean at temperatures around 10 C and the other was isolated from the mojave
desert, where temps reached 45 C - ANS✅✅Mojave desert is likely to have a G-C content of 62%
and the ocean bacteria is likely to have a G-C content of 32%. Organisms that thrive at elevated
temperatures have genomes with a higher fraction of G-C base pairs to stabilize the double helical
structure of their DNA
Which of the following is not a good feature of a plasmid vector?
a. multiple cloning site
b. telomeres
c. antibiotic resistance gene
d. origin of replication
e. blue/white selection system - ANS✅✅b. telomeres
during meiosis, genes that are on opposite ends of a long eukaryotic chromosome:
a. never recombine
b. show less than 50% recombination
c. show exactly 50% recombination
d. show between 50% and 100% recombination
e. show 100% recombination - ANS✅✅c. show exactly 50% recombination
The process of RNA transcription generates an RNA copy of one of the strands of DNA that may then
translated into polypeptide by ribosomes in the cytoplasm. Do all genes encode polypeptides? -
ANS✅✅No. some encode RNA such as rRNA
