BS 161 Final Exam (Answered) 204 Questions
and Correct Answers, With Complete
Verified Solution, Updated Fall 2024/2025.
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.
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.
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.
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.
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.
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
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
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
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
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
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
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.
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.
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.
D)Size is comparable only within phyla.
E)Size matters less than gene density.
B
Fragments of DNA have been extracted from the remnants of extinct woolly mammoths,
amplified, and sequenced. These can now be used to
A)appreciate the reasons why mammoths went extinct.
B)introduce into relatives, such as elephants, certain mammoth traits.
C)clone live woolly mammoths.
D)study the relationships among woolly mammoths and other wool-producers.
E)understand the evolutionary relationships among members of related taxa
E
Why is it unwise to try to relate an organism's complexity with its size or number of cells?
A)A very large organism may be composed of very few cells or very few cell types.
, B)A simple organism can have a much larger genome.
C)A single-celled organism, such as a bacterium or a protist, still has to conduct all the
complex life functions of a large multicellular organism.
D)A complex organism can have a very small and simple genome.
E)A single-celled organism that is also eukaryotic, such as a yeast, still reproduces
mitotically.
C
What is metagenomics?
A)genomics as applied to an entire phylum
B)genomics as applied to a species that most typifies the average phenotype of its genus
C)the sequencing of only the most highly conserved genes in a lineage
D)sequencing DNA from a group of species from the same ecosystem
E)the sequence of one or two representative genes from several species
D
Which of the following most correctly describes a shotgun technique for sequencing a genome?
A)physical mapping followed immediately by sequencing
B)cloning large genome fragments into very large vectors such as YACs, followed by
sequencing
C)cloning the whole genome directly, from one end to the other
D)cloning several sizes of fragments into various size vectors, ordering the clones, and then
sequencing them
E)genetic mapping followed immediately by sequencing
D
What is the difference between a linkage map and a physical map?
A)For a physical map, the ATCG order and sequence must be achieved; however, it does not
for the linkage map.
B)For a linkage map, it is shown how each gene is linked to every other gene.
C)For a physical map, the distances must be calculable in units such as nanometers.
D)For a linkage map, markers are spaced by recombination frequency, whereas for a physical
map they are spaced by numbers of base pairs (bp).
E)There is no difference between the two except in the type of pictorial representation.
D
In large scale, genome-wide association studies in humans, correlation is sought between
A)single nucleotide polymorphisms found in families with a particular introns sequence.
B)lengthy sequences that might be shared by most members of a population.
C)large inversions that displace the centromere.
D)single nucleotide polymorphisms found only in persons with a particular disorder.
E)single nucleotide polymorphisms in two or more adjacent genes.
D
Which of the following modifications is least likely to alter the rate at which a DNA fragment
moves through a gel during electrophoresis?
A)methylating the cytosine bases within the DNA fragment
and Correct Answers, With Complete
Verified Solution, Updated Fall 2024/2025.
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.
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.
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.
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.
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.
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
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
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
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
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
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
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.
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.
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.
D)Size is comparable only within phyla.
E)Size matters less than gene density.
B
Fragments of DNA have been extracted from the remnants of extinct woolly mammoths,
amplified, and sequenced. These can now be used to
A)appreciate the reasons why mammoths went extinct.
B)introduce into relatives, such as elephants, certain mammoth traits.
C)clone live woolly mammoths.
D)study the relationships among woolly mammoths and other wool-producers.
E)understand the evolutionary relationships among members of related taxa
E
Why is it unwise to try to relate an organism's complexity with its size or number of cells?
A)A very large organism may be composed of very few cells or very few cell types.
, B)A simple organism can have a much larger genome.
C)A single-celled organism, such as a bacterium or a protist, still has to conduct all the
complex life functions of a large multicellular organism.
D)A complex organism can have a very small and simple genome.
E)A single-celled organism that is also eukaryotic, such as a yeast, still reproduces
mitotically.
C
What is metagenomics?
A)genomics as applied to an entire phylum
B)genomics as applied to a species that most typifies the average phenotype of its genus
C)the sequencing of only the most highly conserved genes in a lineage
D)sequencing DNA from a group of species from the same ecosystem
E)the sequence of one or two representative genes from several species
D
Which of the following most correctly describes a shotgun technique for sequencing a genome?
A)physical mapping followed immediately by sequencing
B)cloning large genome fragments into very large vectors such as YACs, followed by
sequencing
C)cloning the whole genome directly, from one end to the other
D)cloning several sizes of fragments into various size vectors, ordering the clones, and then
sequencing them
E)genetic mapping followed immediately by sequencing
D
What is the difference between a linkage map and a physical map?
A)For a physical map, the ATCG order and sequence must be achieved; however, it does not
for the linkage map.
B)For a linkage map, it is shown how each gene is linked to every other gene.
C)For a physical map, the distances must be calculable in units such as nanometers.
D)For a linkage map, markers are spaced by recombination frequency, whereas for a physical
map they are spaced by numbers of base pairs (bp).
E)There is no difference between the two except in the type of pictorial representation.
D
In large scale, genome-wide association studies in humans, correlation is sought between
A)single nucleotide polymorphisms found in families with a particular introns sequence.
B)lengthy sequences that might be shared by most members of a population.
C)large inversions that displace the centromere.
D)single nucleotide polymorphisms found only in persons with a particular disorder.
E)single nucleotide polymorphisms in two or more adjacent genes.
D
Which of the following modifications is least likely to alter the rate at which a DNA fragment
moves through a gel during electrophoresis?
A)methylating the cytosine bases within the DNA fragment
