Molecular Biology Exam test quiz
and answers graded A+
Which statement best defines a scientific theory? - ANS✅✅A scientific theory is a concept heavily
supported by scientific evidence and facts.
What experiment did Louis Pasteur perform to disprove the spontaneous generation theory? -
ANS✅✅He used swan neck flasks filled with sterile broth to prove life did not spontaneously
occur.
Which of the Domains of Life DO NOT have a membrane bound nucleus? - ANS✅✅Bacteria and
Archaea
Which component(s) of an atom contribute(s) to the atomic number of an atom? - ANS✅✅Protons
Carbon has an atomic number of 6, so it has ______ electrons in the outermost shell. - ANS✅✅4
Can a hydrogen bond form between the circled atoms in these two molecules? - ANS✅✅No
The adhesive property of water, in which molecules of water are attracted to one another, accounts
for the movement of water to the tops of trees. Which type of bonding is responsible for the
attraction between the water molecules? - ANS✅✅Hydrogen bonds between the water molecules.
Nucleotides are monomers found in which macromolecule? - ANS✅✅DNA and RNA
Hydrolysis of a ____________ bond would result in the degradation of a protein. - ANS✅✅Peptide
In Griffith's experiment which of the following did NOT happen? - ANS✅✅Injecting mice with heat
killed avirulent Streptococcus pneumoniae bacteria killed the mice.
Which of the following statements about DNA is FALSE? - ANS✅✅In a DNA molecule with 34%
guanine, there would be 34% adenine.
,The genes for __________ are transcribed but never translated. - ANS✅✅Transfer RNA and
ribosomal RNA
Which post-transcriptional modification acts as the ribosome binding site in eukaryotes? -
ANS✅✅The 5' CAP
Which statement about translation is FALSE? - ANS✅✅In bacteria, a completely different genetic
code is used to translate the mRNA.
Which of the following is the role of the translation initiation factors? - ANS✅✅Translation
initiation factors help recruit the ribosome to the mRNA and guide the initiation complex to the AUG
start codon.
Which of the following statements is FALSE about translation elongation? - ANS✅✅Elongating
ribosome complexes can be found in the nucleus.
The transport of molecules through a protein embedded channel, from an area of high
concentration across the plasma membrane to an area of low concentration is called ________. -
ANS✅✅Facilitated diffusion
Which of the following is a similarity shared between bacteria and mammalian cells? -
ANS✅✅Both mammalian and bacteria cells have a genome composed of nucleic acids
Which of the following would be expected to increase the fluidity of a membrane? - ANS✅✅A
decrease in phospholipid fatty acid chain length and a decrease in chain saturation
Which of the following could most likely be considered an integral protein? - ANS✅✅A protein
that is responsible for transporting glucose across the cell membrane.
A cell has an internal concentration of 5% salt. If placed in a solution containing 12% salt, what will
happen to the cell? - ANS✅✅Water will move out of the cell causing it to shrivel.
________ are the most heterogenous types of cytoskeleton, composed of a variety of proteins. -
ANS✅✅Intermediate filaments
, Micro filaments and microtubules are both involved in many of the same functions for the cell.
Which of the following functions is unique to microfilaments? - ANS✅✅Muscle contraction.
________ is a protein that bind cells to the extracellular matrix - ANS✅✅Integrin
Proteins embedded in the plasma membrane were originally translated ________ - ANS✅✅By
ribosomes embedded in the rough ER.
Proteins destined for the mitochondria _________. - ANS✅✅Contain an N-terminal signal
sequence and are translated by free ribosomes in the cytosol.
If a ligand is not being produced, what step of signaling would be directly affected? -
ANS✅✅Reception
The signaling type by which a ligand travels through simply diffusion is: - ANS✅✅Paracrine
One of the early experiments that identified ligands, specifically growth factors, caused an increase
in cell division in fibroblast cultures that traditionally were slow to divide. What did they discover
worked the best to stimulate division? - ANS✅✅Serum that was collected after the blood was
allowed to clot
How can you have a cell be a paracrine signaler but not an autocrine signaler? - ANS✅✅It does not
have the specific receptor for the ligand it is releasing
Which of the following statements is TRUE in regards to G-coupled protein receptors? -
ANS✅✅Upon ligand binding the GCPR will activate a G protein which will exchange GDP to GTP
A new poison prevents signal transduction by preventing the dimerization of receptors. What is the
most likely receptor type affected? - ANS✅✅Receptor kinase
What properties do receptor kinases NOT typically have? - ANS✅✅They tend to be short-lasting
signals
What is true of cell signal amplification? - ANS✅✅A single ligand can cause the activation of many
proteins
and answers graded A+
Which statement best defines a scientific theory? - ANS✅✅A scientific theory is a concept heavily
supported by scientific evidence and facts.
What experiment did Louis Pasteur perform to disprove the spontaneous generation theory? -
ANS✅✅He used swan neck flasks filled with sterile broth to prove life did not spontaneously
occur.
Which of the Domains of Life DO NOT have a membrane bound nucleus? - ANS✅✅Bacteria and
Archaea
Which component(s) of an atom contribute(s) to the atomic number of an atom? - ANS✅✅Protons
Carbon has an atomic number of 6, so it has ______ electrons in the outermost shell. - ANS✅✅4
Can a hydrogen bond form between the circled atoms in these two molecules? - ANS✅✅No
The adhesive property of water, in which molecules of water are attracted to one another, accounts
for the movement of water to the tops of trees. Which type of bonding is responsible for the
attraction between the water molecules? - ANS✅✅Hydrogen bonds between the water molecules.
Nucleotides are monomers found in which macromolecule? - ANS✅✅DNA and RNA
Hydrolysis of a ____________ bond would result in the degradation of a protein. - ANS✅✅Peptide
In Griffith's experiment which of the following did NOT happen? - ANS✅✅Injecting mice with heat
killed avirulent Streptococcus pneumoniae bacteria killed the mice.
Which of the following statements about DNA is FALSE? - ANS✅✅In a DNA molecule with 34%
guanine, there would be 34% adenine.
,The genes for __________ are transcribed but never translated. - ANS✅✅Transfer RNA and
ribosomal RNA
Which post-transcriptional modification acts as the ribosome binding site in eukaryotes? -
ANS✅✅The 5' CAP
Which statement about translation is FALSE? - ANS✅✅In bacteria, a completely different genetic
code is used to translate the mRNA.
Which of the following is the role of the translation initiation factors? - ANS✅✅Translation
initiation factors help recruit the ribosome to the mRNA and guide the initiation complex to the AUG
start codon.
Which of the following statements is FALSE about translation elongation? - ANS✅✅Elongating
ribosome complexes can be found in the nucleus.
The transport of molecules through a protein embedded channel, from an area of high
concentration across the plasma membrane to an area of low concentration is called ________. -
ANS✅✅Facilitated diffusion
Which of the following is a similarity shared between bacteria and mammalian cells? -
ANS✅✅Both mammalian and bacteria cells have a genome composed of nucleic acids
Which of the following would be expected to increase the fluidity of a membrane? - ANS✅✅A
decrease in phospholipid fatty acid chain length and a decrease in chain saturation
Which of the following could most likely be considered an integral protein? - ANS✅✅A protein
that is responsible for transporting glucose across the cell membrane.
A cell has an internal concentration of 5% salt. If placed in a solution containing 12% salt, what will
happen to the cell? - ANS✅✅Water will move out of the cell causing it to shrivel.
________ are the most heterogenous types of cytoskeleton, composed of a variety of proteins. -
ANS✅✅Intermediate filaments
, Micro filaments and microtubules are both involved in many of the same functions for the cell.
Which of the following functions is unique to microfilaments? - ANS✅✅Muscle contraction.
________ is a protein that bind cells to the extracellular matrix - ANS✅✅Integrin
Proteins embedded in the plasma membrane were originally translated ________ - ANS✅✅By
ribosomes embedded in the rough ER.
Proteins destined for the mitochondria _________. - ANS✅✅Contain an N-terminal signal
sequence and are translated by free ribosomes in the cytosol.
If a ligand is not being produced, what step of signaling would be directly affected? -
ANS✅✅Reception
The signaling type by which a ligand travels through simply diffusion is: - ANS✅✅Paracrine
One of the early experiments that identified ligands, specifically growth factors, caused an increase
in cell division in fibroblast cultures that traditionally were slow to divide. What did they discover
worked the best to stimulate division? - ANS✅✅Serum that was collected after the blood was
allowed to clot
How can you have a cell be a paracrine signaler but not an autocrine signaler? - ANS✅✅It does not
have the specific receptor for the ligand it is releasing
Which of the following statements is TRUE in regards to G-coupled protein receptors? -
ANS✅✅Upon ligand binding the GCPR will activate a G protein which will exchange GDP to GTP
A new poison prevents signal transduction by preventing the dimerization of receptors. What is the
most likely receptor type affected? - ANS✅✅Receptor kinase
What properties do receptor kinases NOT typically have? - ANS✅✅They tend to be short-lasting
signals
What is true of cell signal amplification? - ANS✅✅A single ligand can cause the activation of many
proteins
