Knowledge Check: Unit 3 — Chapters 11–17 – Biology

Knowledge Check: Unit 3 — Chapters 11–17

Test yourself on Unit 3: Genetics (Chapters 11–17). Every question below was written from the chapters’ own text — their summaries, key terms, explanations, and tables — and none repeats a question from the section pages. There are no hints: treat it like a test. Questions are grouped by the section they come from, so a miss tells you exactly which section to review.

Chapter 11: Meiosis and Sexual Reproduction

11.1 The Process of Meiosis

Which structure do most animal cells and some fungi use to divide the cytoplasm during cytokinesis?

The formation of a close association between homologous chromosomes during prophase I is called ________.

Why have biologists had difficulty testing hypotheses about how meiosis evolved from mitosis, and what four events did Wilkins and Holliday identify as necessary for that evolution?

Your response

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Meiosis is such an extraordinarily complex series of cellular events that biologists have had trouble testing hypotheses concerning how it may have evolved. Adam Wilkins and Robin Holliday summarized the unique events that needed to occur for the evolution of meiosis from mitosis. These steps are homologous chromosome pairing and synapsis, crossover exchanges, sister chromatids remaining attached during anaphase, and suppression of DNA replication in interphase.

Did your answer mention:

meiosis is an extraordinarily complex series of cellular events
biologists have had trouble testing hypotheses concerning how it may have evolved
Wilkins and Holliday summarized the unique events that needed to occur for the evolution of meiosis from mitosis
these steps are homologous chromosome pairing and synapsis, crossover exchanges, sister chromatids remaining attached during anaphase, and suppression of DNA replication in interphase

11.2 Sexual Reproduction

Early in embryonic development, specialized diploid cells that undergo mitosis to perpetuate their own line and meiosis to produce eggs or sperm are called ________.

In asexually reproducing organisms, the only source of genetic variation is ________.

How do meiosis and fertilization together let a sexually reproducing organism alternate between haploid and diploid stages?

Your response

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Meiosis and fertilization alternate in sexual life cycles. The process of meiosis produces unique reproductive cells called gametes, which have half the number of chromosomes as the parent cell. When two haploid gametes fuse, this restores the diploid condition in the new zygote. Thus, most sexually reproducing organisms alternate between haploid and diploid stages.

Did your answer mention:

meiosis and fertilization alternate in sexual life cycles
the process of meiosis produces unique reproductive cells called gametes, which have half the number of chromosomes as the parent cell
when two haploid gametes fuse, this restores the diploid condition in the new zygote

Chapter 12: Mendel’s Experiments and Heredity

12.1 Mendel’s Experiments and the Laws of Probability

Which feature of Mendel’s garden pea experiments let him conclude that his results did not simply come about by chance?

Mendel worked with traits inherited in distinct classes, such as violet versus white flowers, rather than a continuous range of forms — an inheritance pattern known as ________.

What is the difference between an empirical probability and a theoretical probability, and where does each come from?

Your response

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The empirical probability of an event is calculated by dividing the number of times the event occurs by the total number of opportunities for the event to occur. A theoretical probability is calculated by dividing the number of times an event is expected to occur by the number of times it could occur. Empirical probabilities come from observations, like those of Mendel, while theoretical probabilities come from knowing how the events are produced and assuming the probabilities of individual outcomes are equal.

Did your answer mention:

the empirical probability of an event is calculated by dividing the number of times the event occurs by the total number of opportunities for the event to occur
a theoretical probability is calculated by dividing the number of times an event is expected to occur by the number of times it could occur
empirical probabilities come from observations
theoretical probabilities come from knowing how the events are produced and assuming the probabilities of individual outcomes are equal

12.2 Characteristics and Traits

Sort each human trait into the inheritance pattern it follows.

Dominant Traits

Recessive Traits

In the human MN blood groups, a heterozygote expresses both the M and the N antigen equally. This inheritance pattern, in which both alleles for a characteristic are simultaneously expressed in the heterozygote, is called ________.

An inheritance pattern in which an allele is lethal both when present as a single copy and as two copies, and so can only be passed on if death occurs after reproductive age, is called ________.

12.3 Laws of Inheritance

Mendel’s principle that, in a heterozygote, one trait conceals the presence of another trait for the same characteristic is called the ________.

A cross between two true-breeding parents that express different traits for two characteristics is called a ________ cross.

What happens to maternal and paternal alleles during recombination between homologous chromosomes, and does this change the order of the genes?

Your response

Show model answer

During recombination, segments of homologous chromosomes exchange linear segments of genetic material. Because the genes are aligned during recombination, the gene order is not altered. Instead, the result of recombination is that maternal and paternal alleles are combined onto the same chromosome.

Did your answer mention:

segments of homologous chromosomes exchange linear segments of genetic material
the gene order is not altered
maternal and paternal alleles are combined onto the same chromosome

Chapter 13: Modern Understandings of Inheritance

13.1 Chromosomal Theory and Genetic Linkage

Which scientist’s 1902 observation that proper sea urchin embryonic development does not occur unless chromosomes are present helped establish the Chromosomal Theory of Inheritance?

Offspring whose allele combination differs from their parents’, produced by crossing over during meiosis, are called a ________.

Why did Mendel consistently observe independent assortment among the seven traits he studied in pea plants, even though homologous recombination is a common genetic process?

Your response

Show model answer

Researchers have since mapped the seven traits that Mendel investigated onto a pea plant genome’s seven chromosomes and confirmed that all the genes he examined are either on separate chromosomes or are sufficiently far apart as to be statistically unlinked. Mendel consistently observed independent assortment because he examined genes that were effectively unlinked.

Did your answer mention:

researchers have since mapped the seven traits that Mendel investigated onto a pea plant genome's seven chromosomes
all the genes he examined are either on separate chromosomes or are sufficiently far apart as to be statistically unlinked
Mendel consistently observed independent assortment because he examined genes that were effectively unlinked

13.2 Chromosomal Basis of Inherited Disorders

In the process of creating a karyogram, which technique is described as producing approximately 400 to 800 bands of tightly coiled DNA and condensed proteins along the chromosomes?

An individual who has exactly the expected number of chromosomes for their species, such as 22 pairs of autosomes and one pair of sex chromosomes in humans, is called ________.

What chromosomal change produces cri-du-chat syndrome, and what symptom gives the syndrome its name?

Your response

Show model answer

Cri-du-chat syndrome occurs with nervous system abnormalities and identifiable physical features that result from a deletion of most of 5p, the small arm of chromosome 5. Infants with this genotype emit a characteristic high-pitched cry, on which the disorder’s name is based.

Did your answer mention:

occurs with nervous system abnormalities and identifiable physical features
result from a deletion of most of 5p, the small arm of chromosome 5
infants with this genotype emit a characteristic high-pitched cry
on which the disorder's name is based

Chapter 14: DNA Structure and Function

14.1 Historical Basis of Modern Understanding

In Griffith’s experiments, the two strains of Streptococcus pneumoniae were named “rough” and “smooth” after what characteristic?

DNA was first isolated from white blood cells by Friedrich Miescher, who called it ________ because it was isolated from nuclei.

How did Avery, MacLeod, and McCarty determine that DNA, rather than protein, was the transforming principle in bacterial transformation?

Your response

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Avery, MacLeod, and McCarty isolated the S strain’s proteins and nucleic acids, then used enzymes that specifically degraded each component to transform the R strain separately with each one. When DNA was degraded, the resulting mixture was no longer able to transform the bacteria, whereas all of the other combinations were able to transform the bacteria. This led them to conclude that DNA was the transforming principle.

Did your answer mention:

isolated the S strain's proteins and nucleic acids
used enzymes that specifically degraded each component
when DNA was degraded, the resulting mixture was no longer able to transform the bacteria
this led them to conclude that DNA was the transforming principle

14.2 DNA Structure and Sequencing

How many hydrogen bonds hold a cytosine–guanine base pair together in the DNA double helix?

In prokaryotes such as E. coli, the twisting of DNA that is either under-wound or over-wound from its relaxed state, letting a 4.6-million-base-pair chromosome fit inside a small bacterial cell, is called ________.

What recognition did Fred Sanger’s dideoxy chain termination method for sequencing DNA earn him, and in what year?

Your response

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For his work on DNA sequencing, Sanger received a Nobel Prize in Chemistry in 1980.

Did your answer mention:

Sanger received a Nobel Prize in Chemistry
in 1980

14.3 Basics of DNA Replication

In which model of DNA replication do both copies of DNA end up with double-stranded segments of parental DNA and newly synthesized DNA interspersed within a single strand?

The single chromosome of a prokaryote or each chromosome of a eukaryote consists of a single continuous ________.

What did Watson and Crick’s 1953 paper say the specific base pairing they had postulated immediately suggested?

Your response

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Watson and Crick wrote that the specific pairing they had postulated immediately suggested a possible copying mechanism for the genetic material.

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the specific pairing they had postulated
a possible copying mechanism for the genetic material

14.4 DNA Replication in Prokaryotes

Which polymerase is now known to be the main enzyme required for DNA synthesis in prokaryotes?

A ring-shaped protein that binds to the DNA and holds the DNA polymerase in place while it continues adding nucleotides is called the ________.

Why does the leading strand need only one primer, while the lagging strand needs a new primer for each Okazaki fragment?

Your response

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The leading strand can be extended continuously from a single primer toward the replication fork, but the lagging strand is synthesized away from the fork in short Okazaki fragments, each of which requires its own new primer to start synthesis.

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the leading strand can be extended continuously from a single primer
the lagging strand is synthesized away from the fork in short Okazaki fragments
each of which requires its own new primer to start synthesis

14.5 DNA Replication in Eukaryotes

Which protein serves as the eukaryotic sliding clamp that holds DNA polymerase in place during replication?

Which DNA polymerase continuously synthesizes the leading strand during eukaryotic replication?

Why is the rate of DNA replication lower in eukaryotes than in prokaryotes?

Your response

Show model answer

Eukaryotic DNA is bound to histones to form nucleosomes, and the histones must be removed and then replaced during the replication process, which helps to account for the lower replication rate in eukaryotes.

Did your answer mention:

eukaryotic DNA is bound to histones to form nucleosomes
the histones must be removed and then replaced during the replication process
helps to account for the lower replication rate in eukaryotes

14.6 DNA Repair

A variation in the nucleotide sequence of a genome is called a ________.

Which type of point mutation substitutes a stop codon for an amino acid, terminating protein synthesis early?

Why do silent mutations usually not change the function of the protein in which they occur?

Your response

Show model answer

Silent mutations are usually due to a substitution in the third base of a codon, which often represents the same amino acid as the original codon.

Did your answer mention:

a substitution in the third base of a codon
often represents the same amino acid as the original codon

Chapter 15: Genes and Proteins

15.1 The Genetic Code

Because only 16 possible two-nucleotide combinations exist, nucleotide doublets cannot specify every amino acid. How many possible nucleotide triplets exist to encode the 20 amino acids?

In terms of RNA and protein, three “units” of RNA (nucleotides) specifying one “unit” of protein (amino acid) in a consecutive fashion is described as ________.

Why is it considered powerful evidence for a single common origin of life that a horse-globin mRNA transferred into a tulip cell would be translated into horse globin?

Your response

Show model answer

With a few minor exceptions, virtually all species use the same genetic code for protein synthesis. Conservation of codons means that a purified mRNA encoding the globin protein in horses could be transferred to a tulip cell, and the tulip would synthesize horse globin. That there is only one genetic code is powerful evidence that all of life on Earth shares a common origin.

Did your answer mention:

virtually all species use the same genetic code for protein synthesis
a purified mRNA encoding the globin protein in horses could be transferred to a tulip cell, and the tulip would synthesize horse globin
there is only one genetic code
this is powerful evidence that all of life on Earth shares a common origin

15.2 Prokaryotic Transcription

A shorter, circular DNA molecule that may contain one or a few genes and can be transferred independently of the bacterial chromosome during cell division is called a ________.

In prokaryotes, an mRNA transcript that covers more than one gene and is translated to produce more than one kind of protein is called ________.

Explain why the E. coli RNA polymerase’s core enzyme cannot accurately begin transcription without its σ subunit.

Your response

Show model answer

The fifth subunit, σ, is involved only in transcription initiation. It confers transcriptional specificity such that the polymerase begins to synthesize mRNA from an appropriate initiation site. Without σ, the core enzyme would transcribe from random sites and would produce mRNA molecules that specified protein gibberish.

Did your answer mention:

*σ* is involved only in transcription initiation
*σ* confers transcriptional specificity so the polymerase begins to synthesize mRNA from an appropriate initiation site
without *σ*, the core enzyme would transcribe from random sites
this would produce mRNA molecules that specified protein gibberish

15.3 Eukaryotic Transcription

Eukaryotic mRNAs are usually described as ________ because each one specifies only a single protein.

The eukaryotic TATA box, with its consensus sequence TATAAA, sits at approximately which position relative to the transcription initiation (+1) site?

What promoter elements are sufficient on their own to initiate transcription of genes transcribed by RNA polymerase I, and what additional sequences can further enhance that initiation?

Your response

Show model answer

RNA polymerase I transcribes genes that have two GC-rich promoter sequences in the -45 to +20 region. These sequences alone are sufficient for transcription initiation to occur, but promoters with additional sequences in the region from -180 to -105 upstream of the initiation site will further enhance initiation.

Did your answer mention:

RNA polymerase I transcribes genes that have two GC-rich promoter sequences in the -45 to +20 region
these sequences alone are sufficient for transcription initiation to occur
promoters with additional sequences in the region from -180 to -105 upstream of the initiation site will further enhance initiation

15.4 RNA Processing in Eukaryotes

Every intron in a eukaryotic pre-mRNA is marked at its 5′ end by which specific nucleotides?

The RNA molecules that base-pair with a trypanosome pre-mRNA transcript and serve as the catalysts for RNA editing, rather than proteins, are called ________.

Describe how a mature tRNA’s three-dimensional structure positions its two functional ends.

Your response

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Mature tRNAs take on a three-dimensional structure through local regions of base pairing stabilized by intramolecular hydrogen bonding. The tRNA folds to position the amino acid binding site at one end and the anticodon at the other end.

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mature tRNAs take on a three-dimensional structure through local regions of base pairing stabilized by intramolecular hydrogen bonding
the tRNA folds to position the amino acid binding site at one end
the tRNA folds to position the anticodon at the other end

15.5 Ribosomes and Protein Synthesis

A tRNA that interacts with the start codon, binds directly to the ribosome’s P site, and links to a special methionine to begin a polypeptide chain is called the ________.

Which ribosomal component is responsible for binding the mRNA template, while the other subunit sequentially binds tRNAs?

Describe how an aminoacyl tRNA synthetase “charges” a tRNA with its corresponding amino acid.

Your response

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Through the process of tRNA “charging,” each tRNA molecule is linked to its correct amino acid by one of a group of enzymes called aminoacyl tRNA synthetases. These enzymes first bind and hydrolyze ATP to catalyze a high-energy bond between an amino acid and adenosine monophosphate (AMP); a pyrophosphate molecule is expelled in this reaction. The activated amino acid is then transferred to the tRNA, and AMP is released.

Did your answer mention:

each tRNA molecule is linked to its correct amino acid by an aminoacyl tRNA synthetase
these enzymes first bind and hydrolyze ATP to catalyze a high-energy bond between an amino acid and adenosine monophosphate (AMP)
a pyrophosphate molecule is expelled in this reaction
the activated amino acid is then transferred to the tRNA, and AMP is released

Chapter 16: Gene Expression

16.1 Regulation of Gene Expression

The final level of active protein in a cell depends not only on the rate of synthesis but also on the rate of ________ of mRNA and protein.

Which cellular process is thought to have evolved to let a cell quickly shut off gene expression for a short time and survive a viral or parasitic infection?

How does the pattern of gene expression differ between prokaryotic and eukaryotic organisms?

Your response

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Prokaryotic organisms express most of their genes most of the time. However, some genes are expressed only when they are needed. Eukaryotic organisms, on the other hand, express only a subset of their genes in any given cell.

Did your answer mention:

prokaryotic organisms express most of their genes most of the time
some genes are expressed only when they are needed
eukaryotic organisms express only a subset of their genes in any given cell

16.2 Prokaryotic Gene Regulation

The Z gene of the lac operon encodes which product, the one that breaks lactose down into glucose and galactose?

The series of genes necessary to synthesize tryptophan in prokaryotic cells is called the ________.

Explain how a drop in glucose levels leads to increased transcription of the genes needed to process an alternative sugar source, in terms of cAMP and CAP.

Your response

Show model answer

When glucose levels drop, cyclic AMP (cAMP) begins to accumulate in the cell. Accumulating cAMP binds to the positive regulator catabolite activator protein (CAP), and when cAMP binds to CAP, the complex binds to the promoter region of the genes needed to use the alternate sugar source. CAP binding stabilizes the binding of RNA polymerase to the promoter region and increases transcription of the associated protein-coding genes.

Did your answer mention:

when glucose levels drop, cyclic AMP (cAMP) begins to accumulate in the cell
accumulating cAMP binds to the positive regulator catabolite activator protein (CAP)
the complex binds to the promoter region of the genes needed to use the alternate sugar source
CAP binding stabilizes the binding of RNA polymerase to the promoter region and increases transcription

16.3 Eukaryotic Epigenetic Gene Regulation

Adding acetyl groups to histone proteins makes their charge less positive. What effect does this have on the binding between the histones and DNA?

Transcriptional access to eukaryotic DNA is controlled in which two general ways?

What does it mean for a gene to be imprinted, and how can parental diet affect this?

Your response

Show model answer

A gene is imprinted when it is silenced during the development of the gametes of one parent and is transmitted to the offspring in that silenced condition. Parental diet or other environmental conditions may also affect the methylation patterns of genes, which in turn modifies gene expression.

Did your answer mention:

a gene is imprinted when it is silenced during the development of the gametes of one parent
it is transmitted to the offspring in that silenced condition
parental diet or other environmental conditions may also affect the methylation patterns of genes
which in turn modifies gene expression

16.4 Eukaryotic Transcription Gene Regulation

The TATA box, located 25 to 35 bases upstream of the transcriptional start site, is the binding site for which protein complex?

Proteins that bend the DNA so that a distant enhancer region can come into contact with the promoter are called ________ proteins.

How do transcriptional repressors block gene transcription in eukaryotic cells?

Your response

Show model answer

Transcriptional repressors bind to promoter or enhancer regions and block transcription. Like transcriptional activators, repressors respond to external stimuli, but they use that response to prevent the binding of activating transcription factors.

Did your answer mention:

transcriptional repressors bind to promoter or enhancer regions and block transcription
like transcriptional activators, repressors respond to external stimuli
they use that response to prevent the binding of activating transcription factors

16.5 Eukaryotic Post-transcriptional Gene Regulation

Ribonucleoprotein complexes that recognize the two ends of an intron, cut the pre-mRNA transcript at those points, and bring the exons together for ligation are called ________.

After a mature miRNA binds to a complementary mRNA sequence as part of the RNA-induced silencing complex (RISC), what can happen to that mRNA?

How do the 5′ cap and poly-A tail protect a eukaryotic mRNA molecule?

Your response

Show model answer

Before mRNA leaves the nucleus, it is given two protective structures: a 5′ cap, usually a methylated guanosine triphosphate molecule attached to the 5′ end, and a poly-A tail, a long chain of adenine nucleotides attached to the 3′ end. These modifications protect the two ends of the RNA molecule from exonuclease attack.

Did your answer mention:

before mRNA leaves the nucleus, it is given two protective structures
a 5′ cap, usually a methylated guanosine triphosphate molecule attached to the 5′ end
a poly-A tail, a long chain of adenine nucleotides attached to the 3′ end
these modifications protect the two ends of the RNA molecule from exonuclease attack

16.6 Eukaryotic Translational and Post-translational Gene Regulation

In eukaryotes, translation is initiated by binding the initiating met-tRNAi to ________.

What happens immediately after the anticodon of the initiator tRNA aligns with the start codon AUG during translation initiation?

What does the addition of a ubiquitin group signal for a protein, and where is that protein sent as a result?

Your response

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Adding a ubiquitin group to a protein marks that protein for degradation — ubiquitin acts like a flag indicating that the protein’s lifespan is complete. The tagged protein is then moved to the proteasome, an organelle that functions to remove proteins, to be degraded.

Did your answer mention:

adding a ubiquitin group to a protein marks that protein for degradation
ubiquitin acts like a flag indicating that the protein's lifespan is complete
the tagged protein is then moved to the proteasome
an organelle that functions to remove proteins, to be degraded

16.7 Cancer and Gene Regulation

The most-studied tumor-suppressor gene, which is mutated in over 50 percent of all cancer types, encodes a protein that carries out which function in the cell?

The protein that mediates the cell-death pathway and comes in a long and a short form is called ________.

What is personalized medicine, and how does understanding gene expression patterns in individual tumors make it possible?

Your response

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Scientists are using what is known about the regulation of gene expression in disease states, including cancer, to develop new ways to treat and prevent disease development. Many scientists are designing drugs on the basis of the gene expression patterns within individual tumors. This idea, that therapy and medicines can be tailored to an individual, has given rise to the field of personalized medicine. With an increased understanding of gene regulation and gene function, medicines can be designed to specifically target diseased cells without harming healthy cells.

Did your answer mention:

scientists are using what is known about the regulation of gene expression in disease states to develop new ways to treat and prevent disease development
many scientists are designing drugs on the basis of the gene expression patterns within individual tumors
this idea, that therapy and medicines can be tailored to an individual, has given rise to the field of personalized medicine
medicines can be designed to specifically target diseased cells without harming healthy cells

Chapter 17: Biotechnology and Genomics

17.1 Biotechnology

Which bacterium is the source of Taq polymerase, the heat-stable enzyme PCR uses to synthesize new DNA strands?

A single-stranded overhang left by a restriction endonuclease’s staggered cut, able to anneal with a complementary overhang, is called a ________.

What is parthenogenesis, and how does fertilization determine whether an insect or reptile’s parthenogenic egg develops into a male or a female?

Your response

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Parthenogenesis, or “virgin birth,” is a form of asexual reproduction in which an embryo grows and develops without egg fertilization. In species that lay parthenogenic eggs, a fertilized egg is diploid and develops into a female, while an unfertilized egg remains haploid and develops into a male.

Did your answer mention:

parthenogenesis is a form of asexual reproduction in which an embryo grows and develops without egg fertilization
a fertilized egg is diploid and develops into a female
an unfertilized egg remains haploid and develops into a male

17.2 Mapping Genomes

A gene or sequence on a chromosome with a known location that is associated with a specific trait is called a ________.

Which physical mapping method uses x-rays to break DNA into fragments, so that increased or decreased recombination frequency does not affect the resulting map?

How do variable number of tandem repeats (VNTRs) and microsatellite polymorphisms differ as genetic markers?

Your response

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VNTRs are repeated sets of nucleotides present in DNA’s non-coding regions, and the number of repeats may vary in a population’s individual organisms. Microsatellite polymorphisms are similar to VNTRs, but the repeat unit is very small.

Did your answer mention:

VNTRs are repeated sets of nucleotides present in DNA's non-coding regions
the number of repeats may vary in a population's individual organisms
microsatellite polymorphisms are similar to VNTRs, but the repeat unit is very small

17.3 Whole-Genome Sequencing

An individual DNA monomer that is missing a hydroxyl group at the site where another nucleotide normally attaches is called a ________.

Which technique can provide information about all six billion base pairs in the human genome, compared to the roughly one million genotypic abnormalities detectable by DNA microarrays?

How does pairwise-end sequencing improve on the original shotgun sequencing method, which analyzed only one end of each DNA fragment for overlaps?

Your response

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Originally, shotgun sequencing only analyzed one end of each fragment for overlaps, which was sufficient only for small genomes. The desire to sequence larger genomes, such as the human genome, led to developing pairwise-end sequencing, in which scientists analyze each fragment’s end for overlap. Pairwise-end sequencing is more cumbersome than shotgun sequencing, but it is easier to reconstruct the sequence because there is more available information.

Did your answer mention:

shotgun sequencing only analyzed one end of each fragment for overlaps
the desire to sequence larger genomes, such as the human genome, led to developing pairwise-end sequencing
pairwise-end sequencing is more cumbersome than shotgun sequencing
it is easier to reconstruct the sequence because there is more available information

17.4 Applying Genomics

According to genome analysis at the individual level, approximately what percentage of diseases in developed countries results from a single-gene defect?

Genomics is applied to developments such as generating new biofuels, ________ using mitochondria, advances in forensic science, and improvements in agriculture.

How can a patient’s genome sequence information help a doctor prescribe medication under pharmacogenomics?

Your response

Show model answer

Medical professionals can use personal genome sequence information to prescribe medications that will be most effective and least toxic on the basis of the individual patient’s genotype. Studying changes in gene expression could provide information about the transcription profile in the drug’s presence, which can be used as an early indicator of the potential for toxic effects.

Did your answer mention:

medical professionals can use personal genome sequence information to prescribe medications that will be most effective and least toxic on the basis of the individual patient's genotype
studying changes in gene expression could provide information about the transcription profile in the drug's presence
this can be used as an early indicator of the potential for toxic effects

17.5 Genomics and Proteomics

Which protein-imaging technique uses atoms’ magnetic properties to determine a protein’s three-dimensional structure in aqueous solution?

How does two-hybrid screening reveal whether a bait protein and a prey protein interact?

Your response

Show model answer

In two-hybrid screening, a transcription factor splits into a DNA-binding domain (BD) and an activator domain (AD); the bait protein attaches to the BD, and the prey protein attaches to the AD. The binding domain can bind the promoter without the activator domain but does not turn on transcription, so transcription occurs only if the prey “catches” the bait.

Did your answer mention:

a transcription factor splits into a DNA-binding domain (BD) and an activator domain (AD)
the bait protein attaches to the BD, and the prey protein attaches to the AD
transcription occurs only if the prey "catches" the bait

Unlike a genome, a proteome is ________ and in constant flux, which makes it both more complicated and more useful than the knowledge of genomes alone.

This knowledge check is written for Unit 3 (Chapters 11–17) of Biology 2e by Mary Ann Clark, Jung Choi, Matthew Douglas, and OpenStax, © OpenStax, licensed under CC BY-NC-SA 4.0. Access the original for free at openstax.org. Changes: every question is locally written from the pinned text of the chapters’ own modules — their section summaries, glossary definitions, body passages, and comparison tables — and none is transcribed from the book’s exercise sets, which the section pages already carry; no question carries a hint, and every self-check carries a rubric that decomposes a model answer made of the module’s own sentences.

Genomics and Proteomics Evolution and the Origin of Species