BS 161 Final Exam UPDATED ACTUAL
Questions and CORRECT Answers
In yeast signal transduction, the yeast cells
A)secrete molecules that result in response by other yeast cells.
B)must physically and directly interact.
C)produce signal molecules that change themselves so they can interact with one another.
D)produce response molecules that diffuse to other yeast cells.
E)mate, after which the new cells secrete hybrid signals. - CORRECT ANSWER -A
Which of the following is true for the signaling system in an animal cell that lacks the ability to
produce GTP?
A)It would employ a transduction pathway directly from an external messenger.
B)It could activate only the epinephrine system.
C)It would not be able to activate and inactivate the G protein on the cytoplasmic side of the
plasma membrane.
D)It would use ATP instead of GTP to activate and inactivate the G protein on the
cytoplasmic side of the plasma membrane.
E)It would be able to carry out reception and transduction but would not be able to respond
to a signal. - CORRECT ANSWER -C
Because most receptors are membrane proteins, which of the following is usually true?
A)They open and close in response to protein signals.
B)They change their conformation after binding with signal polypeptides.
C)They are only attached to one membrane surface: exterior or interior.
D)They preferentially bind with lipid or glycolipid signal molecules.
E)They lead to changes in intracellular ion concentration. - CORRECT ANSWER -B
,Since steroid receptors are located intracellularly, which of the following is true?
A)The receptor molecules are themselves lipids or glycolipids.
B)The steroid/receptor complex can cross the nuclear membrane.
C)The receptor molecules are free to move in and out of most organelles.
D)The unbound steroid receptors are quickly recycled by lysosomes.
E)The concentration of steroid receptors must be relatively high in most cells. - CORRECT
ANSWER -B
The receptors for a group of signaling molecules known as growth factors are often
A)cyclic AMP.
B)ligand-gated ion channels.
C)neurotransmitters.
D)receptor tyrosine kinases.
E)G protein-coupled receptors. - CORRECT ANSWER -D
Binding of a signaling molecule to which type of receptor leads directly to a change in the
distribution of ions on opposite sides of the membrane?
A)phosphorylated receptor tyrosine kinase dimer
B)ligand-gated ion channel
C)G protein-coupled receptor
D)intracellular receptor
E)receptor tyrosine kinase - CORRECT ANSWER -B
If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of
the following is most likely to result?
A)activation of a developmental pathway found in the worm but not in humans
B)webbing of fingers or toes
C)a form of cancer in which there is insufficient apoptosis
,D)neurodegeneration
E)excess skin exfoliation - CORRECT ANSWER -C
A drug designed to inhibit the response of cells to testosterone would almost certainly result in
which of the following?
A)an increase in cytosolic calcium concentration
B)an increase in receptor tyrosine kinase activity
C)lower cytoplasmic levels of cAMP
D)a decrease in G protein activity
E)a decrease in transcriptional activity of certain genes - CORRECT ANSWER -E
Which of the following is a correct association?
A)GTPase activity and hydrolysis of GTP to GDP
B)adenylyl cyclase activity and the conversion of cAMP to AMP
C)phosphorylase activity and the catabolism of glucose
D)phosphodiesterase activity and the removal of phosphate groups
E)kinase activity and the addition of a tyrosine - CORRECT ANSWER -A
An inhibitor of which of the following could be used to block the release of calcium from the
endoplasmic reticulum?
A)tyrosine kinases
B)adenylyl cyclase
C)serine/threonine kinases
D)phosphodiesterase
E)phospholipase C - CORRECT ANSWER -E
Which of the following most likely would be an immediate result of growth factor binding to its
receptor?
, A)protein kinase activity
B)phosphorylase activity
C)GTPase activity
D)protein phosphatase
E)adenylyl cyclas eactivity - CORRECT ANSWER -A
Barbara McClintock, who achieved fame for discovering that genes could move within genomes,
had her meticulous work ignored for nearly four decades, but eventually won the Nobel Prize.
Why was her work so distrusted?
A)She worked only with maize, which was considered "merely" a plant.
B)Geneticists did not want to lose their cherished notions of DNA stability.
C)She allowed no one else to duplicate her work.
D)The work of women scientists was still not allowed to be published.
E)There were too many alternative explanations for transposition. - CORRECT
ANSWER -B
Which of the following is a representation of gene density?
A)Humans have ~20,000 genes in 2,900 Mb.
B)C. elegans has ~20,000 genes.
C)Fritillaria has a genome 40 times the size of a human.
D)Humans have 27,000 bp in introns.
E)Humans have 2,900 Mb per genome. - CORRECT ANSWER -A
If humans have 2,900 Mb, a specific member of the lily family has 120,000 Mb, and a yeast has
~13 Mb, why can't this data allow us to order their evolutionary significance?
A)Size is mostly due to "junk" DNA.
B)Size does not vary with gene complexity.
C)Size does not compare to gene density.
Questions and CORRECT Answers
In yeast signal transduction, the yeast cells
A)secrete molecules that result in response by other yeast cells.
B)must physically and directly interact.
C)produce signal molecules that change themselves so they can interact with one another.
D)produce response molecules that diffuse to other yeast cells.
E)mate, after which the new cells secrete hybrid signals. - CORRECT ANSWER -A
Which of the following is true for the signaling system in an animal cell that lacks the ability to
produce GTP?
A)It would employ a transduction pathway directly from an external messenger.
B)It could activate only the epinephrine system.
C)It would not be able to activate and inactivate the G protein on the cytoplasmic side of the
plasma membrane.
D)It would use ATP instead of GTP to activate and inactivate the G protein on the
cytoplasmic side of the plasma membrane.
E)It would be able to carry out reception and transduction but would not be able to respond
to a signal. - CORRECT ANSWER -C
Because most receptors are membrane proteins, which of the following is usually true?
A)They open and close in response to protein signals.
B)They change their conformation after binding with signal polypeptides.
C)They are only attached to one membrane surface: exterior or interior.
D)They preferentially bind with lipid or glycolipid signal molecules.
E)They lead to changes in intracellular ion concentration. - CORRECT ANSWER -B
,Since steroid receptors are located intracellularly, which of the following is true?
A)The receptor molecules are themselves lipids or glycolipids.
B)The steroid/receptor complex can cross the nuclear membrane.
C)The receptor molecules are free to move in and out of most organelles.
D)The unbound steroid receptors are quickly recycled by lysosomes.
E)The concentration of steroid receptors must be relatively high in most cells. - CORRECT
ANSWER -B
The receptors for a group of signaling molecules known as growth factors are often
A)cyclic AMP.
B)ligand-gated ion channels.
C)neurotransmitters.
D)receptor tyrosine kinases.
E)G protein-coupled receptors. - CORRECT ANSWER -D
Binding of a signaling molecule to which type of receptor leads directly to a change in the
distribution of ions on opposite sides of the membrane?
A)phosphorylated receptor tyrosine kinase dimer
B)ligand-gated ion channel
C)G protein-coupled receptor
D)intracellular receptor
E)receptor tyrosine kinase - CORRECT ANSWER -B
If an adult person has a faulty version of the human analog to ced-4 of the nematode, which of
the following is most likely to result?
A)activation of a developmental pathway found in the worm but not in humans
B)webbing of fingers or toes
C)a form of cancer in which there is insufficient apoptosis
,D)neurodegeneration
E)excess skin exfoliation - CORRECT ANSWER -C
A drug designed to inhibit the response of cells to testosterone would almost certainly result in
which of the following?
A)an increase in cytosolic calcium concentration
B)an increase in receptor tyrosine kinase activity
C)lower cytoplasmic levels of cAMP
D)a decrease in G protein activity
E)a decrease in transcriptional activity of certain genes - CORRECT ANSWER -E
Which of the following is a correct association?
A)GTPase activity and hydrolysis of GTP to GDP
B)adenylyl cyclase activity and the conversion of cAMP to AMP
C)phosphorylase activity and the catabolism of glucose
D)phosphodiesterase activity and the removal of phosphate groups
E)kinase activity and the addition of a tyrosine - CORRECT ANSWER -A
An inhibitor of which of the following could be used to block the release of calcium from the
endoplasmic reticulum?
A)tyrosine kinases
B)adenylyl cyclase
C)serine/threonine kinases
D)phosphodiesterase
E)phospholipase C - CORRECT ANSWER -E
Which of the following most likely would be an immediate result of growth factor binding to its
receptor?
, A)protein kinase activity
B)phosphorylase activity
C)GTPase activity
D)protein phosphatase
E)adenylyl cyclas eactivity - CORRECT ANSWER -A
Barbara McClintock, who achieved fame for discovering that genes could move within genomes,
had her meticulous work ignored for nearly four decades, but eventually won the Nobel Prize.
Why was her work so distrusted?
A)She worked only with maize, which was considered "merely" a plant.
B)Geneticists did not want to lose their cherished notions of DNA stability.
C)She allowed no one else to duplicate her work.
D)The work of women scientists was still not allowed to be published.
E)There were too many alternative explanations for transposition. - CORRECT
ANSWER -B
Which of the following is a representation of gene density?
A)Humans have ~20,000 genes in 2,900 Mb.
B)C. elegans has ~20,000 genes.
C)Fritillaria has a genome 40 times the size of a human.
D)Humans have 27,000 bp in introns.
E)Humans have 2,900 Mb per genome. - CORRECT ANSWER -A
If humans have 2,900 Mb, a specific member of the lily family has 120,000 Mb, and a yeast has
~13 Mb, why can't this data allow us to order their evolutionary significance?
A)Size is mostly due to "junk" DNA.
B)Size does not vary with gene complexity.
C)Size does not compare to gene density.
