Genetics Review

A human male with the chromosome constitution of XXXYY would contain how many Barr bodies in his somatic cells? 1 4 2 0 3

2

In chickens, the dominant allele Cr produces the creeper phenotype (having extremely short legs). However, the creeper allele is lethal in the homozygous condition. The homozygous recessive genotype results in a normal individual. If two creepers are mated, what will be the phenotypic ratio among the living offspring? 2 normal : 1 creeper 2 creepers : 1 normal 3 creepers : 1 normal 3 normal : 1 creeper 1 normal : 1 creeper

2 creepers : 1 normal

Whereas bacterial cells typically possess only one type of RNA polymerase, most eukaryotic cells possess ___ distinct types of RNA polymerase. 4 2 3 7 12

3

To which part of the mRNA sequence does the RISC bind? 5' UTR stop codon 3' UTR poly(A) tail start codon

3' UTR

Match each vector type to the DNA fragment size that vector may clone 4 KB 20 Kb 35 Kb 100 kB cosmids plasmids bacteriophage bacterial artificial chromosome BAC

4 - plasmids 20- bacteriophage 35- cosmids 100- BAC

A recombination frequency of 5% translates to what distance on a genetic map? 50 m.u. 10 m.u. 1 m.u. 0.5 m.u. 5 m.u.

5 m.u.

A genetic cross with two genes produces 400 offspring, and 20 of them have recombinant phenotypes. What is the recombination frequency for this cross? 20% 1% 5% 50% 10%

5%

A gene has three alleles. How many different genotypes are possible at this locus in a diploid organism? 4 5 7 3 6

6

Which of these is the first step of translation elongation? A peptide bond is formed between the amino acids attached to the tRNAs in the P and A sites. The ribosome translocates down the mRNA in the 5' -> 3' direction. The small and large ribosomal subunits combine with mRNA and the tRNA carrying methionine. The mRNA attaches to the small ribosomal subunit. A charged tRNA binds to the A site.

A charged tRNA binds to the A site.

X-linked red-green color blindness in humans is a recessive condition. Which statement is true? A color‑blind man must have had a color‑blind father. A color‑blind woman must have had a color‑blind father. A color‑blind woman must have had a color‑blind mother. A color‑blind man must have had a color‑blind mother. A man with normal vision cannot have had a color‑blind father.

A color‑blind woman must have had a color‑blind father.

Epistasis often results in modified dihybrid phenotypic ratios. Assume that you obtain one such modified ratio, 9:7, with the gene pairs A and B involved. What would be a possible genotype for a phenotype that would be included with the 9 portion of the modified ratio? Aa bb aa BB aa Bb aa bb Aa BB

Aa BB

Which is an example of a transversion mutation? Thymine is replaced by uracil. Guanine is replaced by adenine. Thymine binds to a neighboring thymine base. Adenine is replaced by thymine. Cytosine is replaced by thymine.

Adenine is replaced by thymine.

The white‑eyed mutation in Drosophila, studied by Thomas Hunt Morgan, was the first clear case of sex‑linked inheritance. When Morgan crossed a white‑eyed female with a red‑eyed male, what phenotypes were present in the offspring? All of the offspring had red eyes. All of the offspring had white eyes. All of the females had white eyes and all of the males had red eyes. All of the males had white eyes and all of the females had red eyes. One‑half of both females and males had red eyes and one‑half had white eyes.

All of the males had white eyes and all of the females had red eyes.

is a type of polyploidy that arises from the hybridization between two different species. Tetrasomy Allopolyploidy Autopolyploidy Paracentric inversion

Allopolyploidy

Which of the statements cannot occur with X‑linked dominant inheritance for a rare trait? An affected woman can pass on the trait to both sons and daughters. An affected man can pass on the trait to his daughter. An affected man can have a normal son. An affected woman can have a normal daughter. An affected man can pass on the trait to his son.

An affected man can pass on the trait to his son.

A geneticist isolates a new restriction enzyme from the bacterium Aeromonas ranidae. No other restriction enzymes have been isolated from this bacterial species. Use the standard convention for abbreviating restriction enzymes to name this new restriction enzyme. AeromonasI IAra AraI AeroI A.RaniI

AraI

Consider the image. Which represents a nucleosome?ABCD

B the whole histone wrapped

A geneticist uses a cloning plasmid that contains the lacZ gene and a gene that confers resistance to penicillin. She inserts a piece of foreign DNA into a restriction site located within the lacZ gene and uses the plasmid to transform bacteria. She then grows the bacteria on selective media containing penicillin and X‑gal. Explain how the geneticist can identify bacteria that contain a plasmid with the foreign DNA. Bacteria with the desired plasmid produce blue colonies. Bacteria with the desired plasmid produce both blue and white colonies. Bacteria with the desired plasmid produce white colonies. Only bacteria with the desired plasmid produce living colonies.

Bacteria with the desired plasmid produce white colonies.

Which statement about chromosome inversions is correct? Chromosome inversions do not affect gene expression. Chromosome inversions flip a segment of a chromosome 180 degrees. Chromosome inversions lead to an increase in crossovers. Chromosome inversions can reduce the number of chromosomes in a cell.

Chromosome inversions flip a segment of a chromosome 180 degrees.

Consider the image. Which represents the 300 nm fibers?ADBC

D Not as tightly wrapped but not seeing histones or nucleosome

Select all that apply. All of the choices are DNA sequencing techniques except Illumina sequencing. pyrosequencing. Sanger dideoxy sequencing. DNA fingerprinting. Mullis chain‑terminating sequencing.

DNA fingerprinting. Mullis chain‑terminating sequencing.

What property of the DNA molecule explains the necessity for Okazaki fragments? DNA is wound around histones. DNA is a linear molecule. DNA is antiparallel. DNA is negatively charged.

DNA is antiparallel.

Which component required for prokaryotic DNA replication is not involved in "unwinding" the DNA template? DNA ligase DNA helicase single‑strand binding proteins DNA gyrase initiator proteins

DNA ligase

Which one of the statements accurately describes gel electrophoresis? DNA moves through the gel toward the positive electrode. Fragments can be visualized by use of infrared light. Larger DNA fragments move more quickly than smaller fragments. Cellulose is used for the gel material. It requires the use of DNA probes.

DNA moves through the gel toward the positive electrode.

What are CpG islands? DNA regions that remove acetyl groups from histone tails DNA regions with many cytosine bases adjacent to guanine bases DNA regions that form complexes with acetylase proteins DNA regions with many cytosine-guanine base pairs DNA regions that are the sites of X inactivation in male mammals

DNA regions with many cytosine bases adjacent to guanine bases

What are insulators? proteins that block the effect of enhancers in a position‑dependent manner proteins that enhance the effect of enhancers in a position‑dependent manner DNA sequences that block the effect of enhancers in an orientation‑dependent manner DNA sequences that block the effect of enhancers in a position‑independent manner DNA sequences that block the effect of enhancers in a position‑dependent manner

DNA sequences that block the effect of enhancers in a position‑dependent manner

Which statement is a feature of both prokaryotic and eukaryotic genes? One promoter controls a cluster of genes. DNA‑binding proteins influence the ability of RNA polymerase to initiate transcription of a gene. Genes are organized into operons. The nuclear membrane separates gene transcription and translation. DNA must be unwound from histone proteins before transcription of a gene takes place.

DNA‑binding proteins influence the ability of RNA polymerase to initiate transcription of a gene.

The Siamese cat breed has a light‑colored body and dark‑colored head, tail, and feet, all of which are called points. The Burmese cat breed has a dark‑colored body and points that are almost the same color as the body. Crossing Siamese with Burmese can produce the Tonkinese cat breed, which has coat and point color that is intermediate to the Siamese and Burmese parents. In all three breeds, a temperature‑sensitive enzyme is responsible for the dark coloration of the points. However, it is active only at the extremes of the body where it is coolest. Select the statements that are true regarding the evidence of incomplete dominance and incomplete penetrance in Siamese, Burmese, and Tonkinese breeds. Burmese with dark color at the head, tail, and feet demonstrates incomplete dominance. Intermediate point color in Tonkinese demonstrates incomplete penetrance. Development of points in Burmese demonstrates incomplete penetrance. Intermediate point color in Tonkinese demonstrates incomplete dominance

Development of points in Burmese demonstrates incomplete penetrance. Intermediate point color in Tonkinese demonstrates incomplete dominance

How are siRNAs and miRNAs made? Slicer processes and cleaves double‑stranded RNA to produce 21‑ to 25‑nucleotide‑long sequences. RNA polymerase methylates RNA, tagging it for cleavage into miRNA and siRNA. RNA polymerase transcribes siRNAs and miRNAs individually based on cellular stimuli. Dicer processes and cleaves double‑stranded RNA to produce 21‑ to 25‑nucleotide‑long sequences. RISC complexes process and cleave double‑stranded RNA to produce 21‑ to 25‑nucleotide‑long sequences.

Dicer processes and cleaves double‑stranded RNA to produce 21‑ to 25‑nucleotide‑long sequences.

Which of the statements is true? Dizygotic twins must be of the same gender, but monozygotic twins can be of different genders. Monozygotic twins develop from one egg fertilized by two sperm, whereas dizygotic twins develop from two eggs fertilized by one sperm. Dizygotic twins, on average, have 50% of their genes in common, whereas monozygotic twins have 100% of their genes in common. The tendency to produce monozygotic twins often runs in families and is influenced by genetic factors, whereas genetic factors seem to have no impact on the occurrence of dizygotic twins. Dizygotic twins usually look more alike than do monozygotic twins

Dizygotic twins, on average, have 50% of their genes in common, whereas monozygotic twins have 100% of their genes in common.

Which statement is most consistent with the one gene, one enzyme hypothesis originally proposed by Beadle and Tatum? Genes and enzymes are important. A gene can only make one enzyme in a cell cycle. Each gene makes one enzyme but not one protein. Every enzyme makes one gene. Every gene encodes a separate enzyme.

Every gene encodes a separate enzyme.

Which does the termination of translation require? terminator tRNA GTP release factors stop codon on the mRNA E site of the ribosomal complex

GTP release factors stop codon on the mRNA

Which statement about mutations is incorrect? Gene mutations affect a single gene, whereas chromosome mutations affect the number or structure of chromosomes. Somatic mutations are numerous, occurring at a rate one per every million cell division. Germ-line and somatic mutations are both passed on to offspring. Mutations are a source of all genetic variation. Mutations can be used to examine biological processes.

Germ-line and somatic mutations are both passed on to offspring.

The eukaryotic protein critical for organizing chromatin structure is histone. Which histone protein is not included in the histone "core" that is often described as the "beads"?H2A H2B H1 H3 H4

H1

Which statement is correct about the reassembly of nucleosomes during replication? Only histones from the original DNA duplex are incorporated into the two new DNA molecules. Histones from the original DNA duplex are mixed with new histones on the two new DNA molecules. This step is performed by the replication licensing factor. Only new histones are incorporated into the two new DNA molecules following replication.

Histones from the original DNA duplex are mixed with new histones on the two new DNA molecules.

Which description about prokaryotic versus eukaryotic DNA replication is not correct? In prokaryotes, there is only a single replication bubble; in eukaryotes, there are many. In prokaryotes, there is only one origin of replication; in eukaryotes, there are many. In prokaryotes, the DNA replication is unidirectional; in eukaryotes, the replication is bidirectional. In both prokaryotes and eukaryotes, the new and old DNA strands are assembled in antiparallel manner. In both prokaryotes and eukaryotes, the DNA undergoes negative supercoiling during replication.

In prokaryotes, the DNA replication is unidirectional; in eukaryotes, the replication is bidirectional.

Comparing sequences between genes and between species allows for the evaluation of mutation rates. Which event has been observed? All mutations occur at the same rate. Exons have a higher mutation rate than introns. Introns have a higher mutation rate than exons. Synonymous mutations occur at the same rate as nonsynonymous mutations. Coding sequences have the same mutation rate as noncoding sequences.

Introns have a higher mutation rate than exons.

Which statement best describes an F' bacterial cell? It contains an F factor that is integrated into the chromosome of the host cell. It has lost the ability to undergo conjugation with an F-cell. It contains an F plasmid that includes some bacterial genes. It is not able to grow on complete medium. It does not contain the F factor.

It contains an F plasmid that includes some bacterial genes.

In the evolution of the mammalian Y chromosome, which is assumed to have occurred? It evolved from an ancestral Y chromosome found in insects such as Drosophila. It evolved from an X chromosome found in some birds. It evolved from a Barr body that underwent multiple rounds of replication. It evolved from an autosome. It evolved from the fusion of two X chromosomes.

It evolved from an autosome.

Which statement best describes linkage? It is a condition in which two or more genes do not show independent assortment. It is a condition where one parent in a cross is homozygous for two or more genes and the other parent is heterozygous. It is a condition where two genes are located on separate chromosomes. It is a condition where a heterozygous individual makes only one type of gamete. It is a condition that occurs in many types of organisms but not in humans because we do not produce sufficient numbers of offspring.

It is a condition in which two or more genes do not show independent assortment.

What is the function of the lac operator? It binds lactose. It produces the lac repressor protein. It is bound by the lac repressor protein. It binds RNA polymerase. It produces an initiator RNA molecule.

It is bound by the lac repressor protein.

Assume that the concordance value for a particular trait is 85% for both monozygotic and dizygotic twins. What can be concluded about this trait? It is caused by genetic factors in dizygotic twins but by environmental factors in monozygotic twins. It is caused by environmental factors in dizygotic twins but by genetic factors in monozygotic twins. It is likely caused almost exclusively by environmental factors. It is caused by both genetic factors and environmental factors. It is likely caused almost exclusively by genetic factors.

It is likely caused almost exclusively by environmental factors.

In a deletion‑mapping experiment, an individual homozygous aa is crossed to an individual that is heterozygous for a deletion. The progeny of this cross all have the wild‑type phenotype. What can be concluded from this cross about the location of gene A? It is in the region adjacent to the deleted region. It is on a sex chromosome. It is on an autosome. It is within the region that is deleted in the heterozygous parent. It is not within the region that is deleted in the heterozygous parent.

It is not within the region that is deleted in the heterozygous parent.

Which statement describes the conservative model of DNA replication correctly? It proposes that both nucleotide strands break down into fragments, which then serve as templates for the synthesis of new DNA molecules. It proposes that the entire double‑stranded DNA molecule serves as a template for a whole new molecule of DNA. It proposes that the two nucleotide strands unwind and each serves as a template for a new DNA molecule.

It proposes that the entire double‑stranded DNA molecule serves as a template for a whole new molecule of DNA.

Which statement describes the semiconservative model of DNA replication correctly? It proposes that the entire double‑stranded DNA molecule serves as a template for a whole new molecule of DNA. It proposes that the two nucleotide strands unwind and each serves as a template for a new DNA molecule. It proposes that both nucleotide strands break down into fragments, which then serve as templates for the synthesis of new DNA molecules.

It proposes that the two nucleotide strands unwind and each serves as a template for a new DNA molecule.

How does direct repair return DNA errors to their original sequences? The base is first removed before the entire nucleotide is replaced. It uses the other copy of the DNA molecule to replicate the original sequence. It removes functional groups or bonds from the altered nucleotide to restore the original structure. It uses an exonuclease to remove the incorrect sequence and replace it. It replaces altered nucleotides with the correct nucleotides.

It removes functional groups or bonds from the altered nucleotide to restore the original structure.

Which statement about cellular DNA in incorrect? DNA exists in the cell as very long, tightly packed molecules. Supercoiling allows cellular DNA to be packed into a small space. Most cellular DNA is positively supercoiled. Supercoiling of cellular DNA is controlled by topoisomerases. Supercoiling makes the separation of the two strands of DNA easier for replication and transcription.

Most cellular DNA is positively supercoiled.

Which statement about aneuploidy is true? Aneulploidy is a change in number of chromosome sets. The rarest aneuploidies in humans are those of the sex chromosomes. Most autosomal aneuploids develop normally and have a normal life span. One form of aneuploidy is a loss of both members of a homologous pair of chromosomes.

One form of aneuploidy is a loss of both members of a homologous pair of chromosomes.

Until the 1970s, only a small number of bacterial species had been studied compared to the total number present throughout the world. Which explanation was the main reason for this failure? Since bacteria reproduce asexually, it was assumed that their life cycle would be too simple to be biologically important. Funding was available only to study bacteria that caused diseases in humans. It was assumed that all bacterial species are very similar, so studying a few species would reveal the properties of all bacteria in general. Only a small number of bacterial species could be cultured in the laboratory where they could be studied with standard techniques of microbiology. It was assumed that bacteria have limited importance because they are mainly unicellular and most are not medically significant.

Only a small number of bacterial species could be cultured in the laboratory where they could be studied with standard techniques of microbiology.

Which statement about polyploidy is not true? Polyploidy is found in many of the food crop plants we enjoy, such as bananas and strawberries. Polyploidy is a major mechanism by which new plant species have evolved. Polyploidy is possible only between the members of the same species. Polyploidy results from failure to separate a whole set of chromosomes during cell division. Polyploidy often results in larger cell size.

Polyploidy is possible only between the members of the same species.

Identify examples of reverse genetics. mutation from mutant allele to wild‑type allele gene knockout using site‑directed mutagenesis RNA interference two‑hybrid test mutation from wild‑type allele to mutant allele & Which statement represents the definition of a reversion (reverse mutation)? site‑directed mutagenesis mutation from wild‑type allele to mutant allele two‑hybrid test RNA interference mutation from mutant allele to wild‑type allele

RNA interference . gene knockout using site-directed mutagenesis. & mutation from mutant allele to wild‑type allele

There are 64 codons, 20 different amino acids, and approximately 30-50 tRNAs. Which statement does not help explain these numbers? Isoaccepting tRNAs can carry the same amino acid. Flexibility, or wobble, between the anticodon and the codon allows one tRNA to pair with multiple codons. Many amino acids are coded for by more than one of the 61 sense codons. The 3' base of the anticodon on the tRNA can pair weakly with the 5' codon base. Synonymous codons code for the same amino acid.

The 3' base of the anticodon on the tRNA can pair weakly with the 5' codon base.

Why are transcriptional regulator proteins necessary? The basal transcription apparatus will repress transcription without them. The transcriptional regulator proteins keep the apparatus from being degraded by enzymes. The basal transcription apparatus will not bind to the promoter without them. The transcriptional regulator proteins will recruit RNA polymerases. The basal transcription apparatus can only produce minimal levels of transcription without them.

The basal transcription apparatus can only produce minimal levels of transcription without them.

Which was not shown by Watson and Crick's model of DNA? There could be a means for DNA to easily replicate itself. One adenine would pair with one thymine. The bases face outside for easy access. The helices are right handed. The strands run in opposite directions.

The bases face outside for easy access.

A yellow female Labrador retriever was mated with a brown male. Half of the puppies were brown, and half were yellow. Explain how the same female, when mated with a different brown male, could produce only brown offspring. The first male was bb EE, and the second male was bb Ee. The first male was Bb EE, and the second male was Bb Ee. The first male was bb Ee, and the second male was bb ee. The first male was bb Ee, and the second male was bb EE. The first male was bb Ee, and the second male was Bb Ee.

The first male was bb Ee, and the second male was bb EE.

In a testcross involving two heterozygous genes, equal numbers of recombinant and nonrecombinant progeny are produced. From this result, what can be concluded? One of the two genes is lethal when homozygous. The genes are linked, and there is some crossing over between them. The genes are linked, but there is no crossing over between them. The genes are located very close to each other. The genes are not linked.

The genes are not linked.

Which of the statements about the genetic code are most accurate? Three initiation codons set the three possible reading frames. The genetic code is generally overlapping. The promoter sets the reading frame. The genetic code is generally‑non‑overlapping. An initiation codon sets the reading frame.

The genetic code is generally‑non‑overlapping. An initiation codon sets the reading frame.

Which statements about euchromatin and heterochromatin are correct? Heterochromatin is less condensed than euchromatin. Most genes are present in heterochromatin. Euchromatin largely consists of repeated sequences. The majority of transcription takes place on euchromatin. Euchromatin undergoes condensation and decondensation throughout the cell cycle.

The majority of transcription takes place on euchromatin. Euchromatin undergoes condensation and decondensation throughout the cell cycle.

Choose the true statements using the information presented in the phylogenetic tree. The mountain zebra is more closely related to the wild ass than to the half ass. The Przewalski horse is more closely related to any zebra than to the wild ass. The percentage similarity between two species can be calculated by tracing the branch length. The horses and zebras share approximately 93% of their genomic sequence. The domestic horse is the ancestor of the Burchell zebra.

The mountain zebra is more closely related to the wild ass than to the half ass. The percentage similarity between two species can be calculated by tracing the branch length.

A three‑point linkage analysis found a coefficient of coincidence value of 1.0. What does this value reveal about the number of observed double crossovers in the progeny? There was interference that reduced the number of observed double crossovers. The number of observed double crossovers was the same as the number of double crossovers predicted by probability. The number of observed double crossovers was less than the number of double crossovers predicted by probability. The number of observed double crossovers was greater than the number of single crossovers. The number of observed double crossovers was greater than the number of double crossovers predicted by probability.

The number of observed double crossovers was the same as the number of double crossovers predicted by probability.

What does the term antiparallel mean? The strands run in opposite directions. The strands run in the same direction. The 5' end of one strand is opposite the 3' end of the second strand. The strands separate in opposite directions. The 5' end of one strand is opposite the 5' end of the second strand.

The strands run in opposite directions. The 5' end of one strand is opposite the 3' end of the second strand.

When two genes show a high frequency of cotransduction, it can be assumed that which statement is true? Two phages have transduced two different genes. The two genes are located close to each other. There is a high level of crossing over between the two genes. The two genes are far apart but located on the same chromosome. The two genes are located on different chromosomes.

The two genes are located close to each other.

Which statement best describes genetic maps? They are best constructed from the results of crosses between two homozygous individuals. They are based on recombination frequencies between genes. In humans, they are based on the results of somatic‑cell hybridization experiments. They cannot be determined between two genes if the genes are in the repulsion configuration. They are determined by the number of nucleotides between two genes.

They are based on recombination frequencies between genes.

Which statement is not true about repressors in eukaryotic cells? They directly block RNA polymerase. They can interfere with the assembly of the basal transcription apparatus. They can bind near an activator site and prevent activator contact with the basal transcription apparatus. They can compete with activators for DNA‑binding sites. They bind to silencer sequences.

They directly block RNA polymerase.

Which is not a valid statement about the characteristics that make bacteria and viruses advantageous for many genetic studies? They have large and complex genomes. Mutants are easily obtained and studied. Different strains that have been isolated are easy to grow under laboratory conditions. Reproduction is rapid, and many progeny are produced. Techniques are available for isolating and manipulating their genes.

They have large and complex genomes.

Which statement about retroviruses is not true? They can make a DNA copy of their genome that integrates into the host cell genome. They have three genes in common, and each gene can produce more than one type of protein. They may contain oncogenes. They replicate their DNA genomes in the cytoplasm of host animal cells. They produce the enzyme reverse transcriptase.

They replicate their DNA genomes in the cytoplasm of host animal cells.

Which of the statements about the process of transcription in archaea is the most accurate? Transcription in archaea is most similar to that in eukaryotes. Transcription in archaea is very similar to transcription in both bacteria and eukaryotes. Transcription in archaea is most similar to that in bacteria. Transcription in archaea has no common elements with transcription in either bacteria or eukaryotes.

Transcription in archaea is most similar to that in eukaryotes.

Which statement about chromosome translocation is correct? Translocation can affect gene expression by moving a gene under the control of a different promoter. Translocations do not affect chromosome number. Translocations only take place within a chromosome. Translocation and "crossing over" refer to the same phenomenon.

Translocation can affect gene expression by moving a gene under the control of a different promoter.

How does transposition cause mutations? Transposable elements can insert themselves into other genes and disrupt their function. Transposable elements are carcinogens. Transposable elements can infect other cells and disrupt their genes. Transposition "tags" the gene for degradation. Transposition changes which amino acid is loaded onto a specific tRNA.

Transposable elements can insert themselves into other genes and disrupt their function.

Which statement about Down syndrome is true? The probability of a child having Down syndrome does not correlate with maternal age. Trisomy of chromosome 21 is well tolerated enough to give rise to fully‑developed individuals. Down syndrome never runs in the family, as it is based on a random aneuploidy event. The primary cause for Down syndrome is the Robertsonian translocation.

Trisomy of chromosome 21 is well tolerated enough to give rise to fully‑developed individuals.

True or false: All chromosomes of the same species would have the same centromeric positions. True False

True

Question Humans with only one sex chromosome (XO) usually have underdeveloped sexual characteristics and are sterile. What is this condition called? Turner syndrome Androgen-insensitivity syndrome Klinefelter syndrome Nondisjunction Lyon hypothesis

Turner syndrome

Assume that a single crossover occurs between two genes during meiosis. What would be the consequence of this crossover event? Three chromatids will be nonrecombinant, and one will be recombinant. Two of the four chromatids will be recombinant, and two will be nonrecombinant. Three chromatids will be recombinant, and one will be nonrecombinant. All of the chromatids will be recombinant. All of the chromatids will be nonrecombinant.

Two of the four chromatids will be recombinant, and two will be nonrecombinant.

My Attempt Which statement is false? The archaea are a diverse group of prokaryotes often found in extreme environments. Most prokaryotes are unicellular organisms that lack nuclear membranes. Unlike eukaryotes, bacteria do not have proteins to help condense their DNA. Prokaryotes consist of the archaea and the eubacteria (bacteria). The archaea are more similar to eukaryotes than to eubacteria for some genetic and molecular processes.

Unlike eukaryotes, bacteria do not have proteins to help condense their DNA.

Which statement best describes the difference between virulent phages and temperate phages? Virulent phages can go through only the lytic cycle, whereas temperate phages can undergo either the lytic cycle or the lysogenic cycle. Virulent phages have circular RNA genomes, whereas temperate phages have linear DNA genomes. Virulent phages are able to carry out both specialized transduction and generalized transduction, whereas temperate phages can only carry out generalized transduction. Virulent phages can integrate their genomes into the host bacterial chromosome, whereas temperate phages are not able to do this. Virulent phages cannot produce plaques after infecting a bacterial host, whereas temperate phages can produce plaques under some conditions.

Virulent phages can go through only the lytic cycle, whereas temperate phages can undergo either the lytic cycle or the lysogenic cycle.

What is the role of tryptophan in the regulation of the trp operon? When tryptophan levels are high, tryptophan stimulates the transcription of the trp regulatory gene. When tryptophan levels are high, tryptophan binds to the inactive trp repressor, making it active. When tryptophan levels are high, tryptophan binds to RNA polymerase to stimulate transcription. When tryptophan levels are low, tryptophan inactivates the trp repressor. When tryptophan levels are low, tryptophan stimulates the transcription of the structural genes.

When tryptophan levels are high, tryptophan binds to the inactive trp repressor, making it active.

Use the information gathered in the Interpretation of a Pedigree animation to answer the question. Consider the list. pattern shows sex bias with more affected males than females affected sons are usually born to unaffected mothers tends to skip a generation never passes from father to son all daughters of affected fathers are carriers Which of the inheritance patterns best fits the pedigree characteristics described in the list? X‑linked recessive autosomal recessive X‑linked dominant Y‑linked autosomal dominant

X‑linked recessive

Some human proteins that are used in therapeutics, such as insulin, can be produced by genetically modified yeast. Though genetically modified bacteria can also be used to produce these therapeutics, yeast is considered by many to be the superior type of organism to use for this purpose. What is the advantage of using yeast cells instead of bacterial cells when expressing human proteins? Yeast cells fold and modify proteins in a manner similar to human cells. Yeast cells splice mRNAmRNA in an identical manner as human cells. Yeast cells use the same genetic code for specifying amino acids as human cells. Yeast cells grow faster than bacterial cells when expressing human proteins.

Yeast cells fold and modify proteins in a manner similar to human cells.

A left‑handed form of DNA is the A‑DNA. H‑DNA. B‑DNA. Z‑DNA.

Z‑DNA.

During the rho-independent termination of transcription in some bacteria, the formation of ___________ is critical. a Rho enzyme a hairpin loop via inverted repeats a terminator sequence an RNA-DNA duplex a Rut site

a hairpin loop via inverted repeats

A structure formed by a single‑stranded DNA or RNA molecule that has complementary sequences is a hairpin. a methylated strand. a helix. a triple strand.

a hairpin.

What is a conditional mutation? a mutation that affects the phenotype only under certain conditions a mutation that affects the phenotype only when the organism is ill a mutation that affects the genotype only under certain conditions a mutation that makes it easier for organisms to contract diseases a mutation that occurs only under certain conditions

a mutation that affects the phenotype only under certain conditions

What is a missense mutation? a mutation that changes a codon to a synonymous codon a mutation whose effect is not yet known a mutation that changes a codon that specifies an amino acid to one that terminates translation a mutation that results in a different amino acid in a protein a mutation that alters the reading frame of the gene

a mutation that results in a different amino acid in a protein

A strong covalent bond between adjacent nucleotides is an ionic bond. a hydrogen bond. a phosphate bond. a phosphodiester bond. a van der Waals bond.

a phosphodiester bond.

What is the clear patch of lysed cells on a continuous layer of bacteria on the agar surface of a petri plate called? a plaque a colony a transduction a fertility factor a transformation

a plaque

An individual unit of replication is referred to as a replication fork. a negative supercoil. antiparallel. a replicon. a double helix.

a replicon.

What is the regulatory segment of an mRNA that binds a small molecule resulting in a change in the production of the protein encoded by this mRNA called? a repressor an activator a promoter a riboswitch an attenuator

a riboswitch

What is chromatin immunoprecipitation? a technique that determines where proteins are localized in the cell a technique that determines the specific locations within the genome where proteins interact with DNA a technique that determines how many chromosomes are in a cell a technique that determines which strand of DNA is the template strand a technique that determines the sequence of the DNA in specific chromosomes

a technique that determines the specific locations within the genome where proteins interact with DNA

What is the Ames test? a test to determine how to reverse DNA mutations a test to screen for mutagenic chemicals a test to find the cause of mutation a test to determine the phenotype of a mutation a test to determine the rate of mutation

a test to screen for mutagenic chemicals

Consider this figure when answering the question. Which term correctly describes the eukaryotic chromosome figure based on the centromere position? submetacentric telocentric acrocentric metacentric

acrocentric

What is a purine? Select all that apply. adenine or guanine cytosine or uracil a base with two rings a base with one ring a nucleoside

adenine or guanine a base with two rings

If a man exhibits a Y‑linked trait, what proportion of his sons should also be affected? all none one‑fourth three‑fourths one‑half

all

Which process is based on DNA recombination? all of these crossover homologous recombination bacterial conjugation DNA repair

all of these

Eukaryotic DNA consists of moderately repetitive DNA sequences. all of these. unique sequences of DNA. highly repetitive DNA sequences.

all of these.

Which choice is the true inducer of the lac operon? glucose galactose cAMP allolactose lactose

allolactose

Proteins that change shape on binding to another molecule are called allosteric proteins. inducible proteins. antisense proteins. activator proteins. structural proteins.

allosteric proteins.

Which of the types of bacterial cells would normally be able to undergo conjugation with an F+ cell? an F' cell either an F+ or an F' cell another F+ cell an F- cell an Hfr cell

an F- cell

The major contribution of Franklin and Wilkins to the study of DNA was creation of bacteriophages specific for studying DNA. use of a blender to separate virus coats off cells. use of specific enzymes to destroy one molecule. an X‑ray diffraction pattern. a ball‑and‑stick model.

an X‑ray diffraction pattern.

What is a proband? the karyotype of a normal fetus obtained through amniocentesis a woman who becomes pregnant and requests genetic counseling an individual who is found to be carrying a recessive mutant allele during a heterozygote screening program an individual who undergoes newborn screening for a genetic disorder that can be treated if detected early an affected individual in a pedigree who brings the family to the attention of the medical community

an affected individual in a pedigree who brings the family to the attention of the medical community

A small RNA that can base pair with an mRNA molecule and affects its functioning is called an antisense RNA. a repressor. an inducer. a riboswitch. an activator.

an antisense RNA.

A plasmid that is capable of integrating into a bacterial chromosome is called a plaque. an auxotroph. a transductant. an episome. a provirus.

an episome.

Evolution within a single lineage is known as cladogenesis. speciation. the biological species concept. anagenesis.

anagenesis.

What does diagram B in Figure 8.3 represent? chromosome translocation aneuploidy chromosome duplication polypoidy

aneuploidy

What is the phenomenon called where there is stronger or earlier expression of a genetic trait in succeeding generations? pleiotrophy epistasis reduced penetrance anticipation variable expressivity

anticipation

What is the process called in which a virus has undergone major changes in its genome through the reassortment of genetic material from different strains of the virus? integration antigenic drift specialized transduction transformation antigenic shift

antigenic shift

The biological species concept cannot be readily applied when studying species that produce a low number of offspring. polyploid species. geographically isolated groups. species exhibiting a high amount of genetic variation. asexually reproducing organisms.

asexually reproducing organisms.

A mechanism of genetic regulation in which the synthesis of a short RNA is terminated before the structural genes of the operon can be transcribed is called repression. induction. positive control. negative control. attenuation.

attenuation.

Use the information gathered in the Interpretation of a Pedigree animation to answer the question. Consider the list. usually appears in both sexes with equal frequency both parents can transmit the trait to their offspring affected offspring most commonly have an affected parent unaffected parents do not transmit the trait does not skip generations Which of the inheritance patterns best fits the pedigree characteristics described in the list? X‑linked recessive autosomal dominant autosomal recessive X‑linked dominant Y‑linked

autosomal dominant

A trait appears in both men and women with equal frequency, and offspring can inherit the trait from the mother or the father. All affected individuals have at least one affected parent. This trait is autosomal dominant. X‑linked dominant. Y‑linked. autosomal recessive. X‑linked recessive.

autosomal dominant.

Use the information gathered in the Interpretation of a Pedigree animation to answer the question. Consider the list. affected offspring are usually born to unaffected parents usually appears in both sexes with equal frequency tends to skip a generation appears more frequently among the children of consanguine (first cousin) marriages Which of the inheritance patterns best fits the pedigree characteristics described in the list? Y‑linked autosomal dominant X‑linked recessive autosomal recessive X‑linked dominant

autosomal recessive

Mutant bacterial strains that lack one or more enzymes needed to make essential molecules are called temperate. transductants. prototrophs. auxotrophs. transformant.

auxotrophs.

Which mutagens incorporate into DNA and frequently pair with the wrong base? base analogs alkylating agents oxidative radicals hydroxylamine deaminating chemicals

base analogs

How is the transcription start site determined in bacteria? by the binding of the first primer by the binding of RNA polymerase to the consensus sequences of the promoter by the presence of the TATA box by the presence of a DNA bubble by the presence of an enhancer element

by the binding of RNA polymerase to the consensus sequences of the promoter

A system of gene control in bacterial operons in which glucose is used preferentially and the metabolism of other sugars is repressed in the presence of glucose is called antisense regulation. attenuation. coordinate induction. negative control. catabolite repression.

catabolite repression.

Which statistical test can be used to determine if two genes are linked? determination of interference the single nucleotide polymorphism test chi‑square test of independence the coefficient of coincidence deletion mapping

chi‑square test of independence

Which organelle or organelles contain DNA of their own? Golgi apparatus chloroplasts mitochondria endoplasmic reticulum

chloroplasts mitochondria

What does diagram A in Figure 8.3 represent? chromosome deletion chromosome translocation chromosome duplication chromosome inversion

chromosome duplication

A man and a woman are both deaf due to being homozygous for a recessive autosomal mutant allele. However, they are homozygous recessive at different gene loci. If all their children have normal hearing, which event has occurred within each child? complementation incomplete dominance codominance epistasis gene interaction

complementation

Which method of gene transfer in bacteria requires physical contact between donor and recipient cells? specialized transduction replication transformation generalized transduction conjugation

conjugation

Frequently, important DNA regions with specific functions tend to contain short stretches of nucleotides that are conserved across different organisms (e.g., promoter sequence) and are recognized by specific proteins. What are these conserved sequences called? consensus sequences critical elements codons repetitive sequences initiators

consensus sequences

Which RNA type is found only in prokaryotes? rRNA crRNA tRNA snRNA mRNA

crRNA

In humans, mitochondrial genetic disorders are inherited from only the mother. The severity of such diseases can vary greatly, even within a single family. What form of inheritance does this represent? genetic maternal effect sex‑influenced inheritance cytoplasmic inheritance sex‑limited inheritance genomic imprinting

cytoplasmic inheritance

Which nucleotide base is methylated in DNA methylation? guanine cytosine uracil thymine adenine

cytosine

When a solution containing double‑stranded DNA is heated, the hydrogen bonds that hold the two strands can be weakened and eventually broken, separating the strands completely. This process is called double‑strand break. hybridization. renaturation. denaturation.

denaturation.

What is the term that refers to a pair of twins where one twin has the trait under consideration and the other twin does not? proband consanguine discordant concordant dizygotic

discordant

Three‑point testcrosses are often used to map genes. The two least frequent classes from such crosses usually represent which types of progeny? double‑crossover progeny nonrecombinant progeny half the nonrecombinant progeny single‑crossover progeny one nonrecombinant class and one single‑crossover class of progeny

double‑crossover progeny

What type of gene action occurs when one gene masks the effect of another gene at a different locus? genomic imprinting anticipation epigenetics epistasis complementation

epistasis

True or false: The C value, which indicates the amount of DNA in a haploid genome, always correlates to the complexity of the organism. true false

false

The largest and most complex mitochondrial genomes come from mice. humans. flowering plants. yeasts. fruit flies.

flowering plants.

In eukaryotic cells, promoter consensus sequences are recognized by accessory proteins that recruit a specific RNA polymerase. Which of the types of accessory proteins serve this purpose? transcription activators transcription repressors single‑strand‑binding proteins general transcription factors enhancer

general transcription factors

A gene whose expression is affected by the sex of the transmitting parent demonstrates which of the events? pleiotropy epigenetics anticipation genetic maternal effect genomic imprinting

genomic imprinting

A phage cross is made with phage T2. One of the parents was h+r− and the other parent was h−r+. What would be the two recombinant classes of progeny from this cross? h+r− and h−r+ h+r− and h+r+ h+r+ and h−r+ h+r− and h−r− h+r+ and h−r−

h+r+ and h−r−

Which term describes the situation, for X‑linked genes, in human and Drosophila males who have only one X chromosome? dioecious homozygous homogametic heterozygous hemizygous

hemizygous

Most of the centromere and telomere structures consist of euchromatin heterochromatin kinetochore GC repeats

heterochromatin

Which statements about primers are correct? They are synthesized by an enzyme called primase. They provide a 3′−OH3′−OH group for attachment of DNA nucleotides. They are needed for the start of DNA synthesis. They are synthesized by DNA polymerase α.

hey are synthesized by an enzyme called primase. They provide a 3′−OH3′−OH group for attachment of DNA nucleotides. They are needed for the start of DNA synthesis. They are synthesized by DNA polymerase α.

Genetic variation in natural populations tends to be low because of weak selection. high because of neutral polymorphisms. high because of rapidly changing environments. low because of neutral polymorphisms. high because of intensive selection.

high because of neutral polymorphisms.

Which set of conditions will lead to the highest expression of the lac structural genes? low levels of lactose and high levels of glucose high levels of the lac repressor and high levels of glucose low levels of lactose and low levels of glucose high levels of lactose and low levels of glucose high levels of lactose and high levels of glucose

high levels of lactose and low levels of glucose

Bacteria have acquired genes from other species of bacteria and sometimes from eukaryotic cells. The processes by which this occurs are known collectively as cotransformation. horizontal gene transfer. interrupted conjugation. reverse transcription. cotransduction.

horizontal gene transfer.

Which mechanism is not a prezygotic reproductive isolating mechanism? behavioral isolation mechanical isolation hybrid sterility ecological isolation temporal isolation

hybrid sterility

Fur color in a species of mouse is controlled by a single gene pair. BB animals are black and bb animals are white. Bb animals have gray fur and each hair is gray. What type of interaction is being shown by the two alleles in heterozygous animals? codominance epistasis complete dominance complementation incomplete dominance

incomplete dominance

Which of the examples listed is not a DNA repair mechanism? direct repair nucleotide‑excision repair insertion sequence repair mismatch repair base‑excision repair

insertion sequence repair

All of the choices are required for genome editing with the CRISPR‑Cas9 system except an sgRNA. a PAM sequence. a repair mechanism for a double‑strand DNA break (DSB). Cas9 nuclease. invading DNA protospacers.

invading DNA protospacers.

The sugar in DNA is called "deoxyribose" because it contains a 2'−OH−OH group. binds the nitrogen base via an OO atom. is missing a 2'−OH−OH group. is missing a 3'−OH−OH group. is missing a 5'−OH−OH group.

is missing a 2'−OH−OH group.

What characteristic is not necessary for a molecule that is the genetic material? It must have the ability to replicate faithfully. It must encode the phenotype. It must contain complex information. It must be variable. It must perform the action associated with the phenotype.

it must perform the action associated with the phenotype.

The spread of a complete metaphase chromosome set presented for diagnostic purposes is called a . karyotype. genome. polyploidy. translocation.

karyotype

Which modes of replication is bidirectional, antiparallel, both continuous and discontinuous, and has multiple replicons? theta replication rolling‑circle replication linear eukaryotic replication

linear eukaryotic replication

Which option describes a nonrandom association between alleles in a haplotype? single‑nucleotide polymorphism interference linkage disequilibrium coefficient of coincidence repulsion linkage

linkage disequilibrium

Which class of RNA serves as the coding instruction read by the ribosome to produce a polypeptide chain? tRNA rRNA miRNA snRNA mRNA

mRNA

How do mismatch‑repair enzymes in E. coli differentiate between the old and new strands of DNA? methylation of the adenine in the GATC sequence of the old strand phosphorylation of the adenine in the GATC sequence of the old strand methylation of adenine in the GATC sequence of the new strand phosphorylation of the adenine in the GATC sequence of the new strand acetylation of the adenine in the GATC sequence of the old strand

methylation of the adenine in the GATC sequence of the old strand

Which processes ensure the high accuracy of replication? mismatch repair proofreading replication licensing nucleotide selection linear replication

mismatch repair proofreading nucleotide selection

The advantages of studying the processes and patterns of evolution using molecular data include all of the observations except that molecular data directly reflect genetic differences. molecular data are directly reflected in phenotype. molecular data can be quantified. molecular data can be used to compare different species. molecular data can be applied to large amounts of genetic variation.

molecular data are directly reflected in phenotype.

What is an environmental agent that significantly increases the rate of mutation above the spontaneous rate called? tautomer missense agent Ames agent mutagen transposon

mutagen

When a circular DNA gets underrotated by the action of cellular enzymes, the DNA is said to exhibit relaxed state. positive supercoiling. negative supercoiling. bubbling.

negative supercoiling.

Failure to separate for homologous chromosomes or sister chromatids is referred to as . nondisjunction. Robertsonian translocation. gene dosage effect. pseudodominance.

nondisjunction.

A trait shows X‑linked dominant inheritance. A normal daughter of an affected mother marries a normal man. What proportion of their children will be affected? one‑half all none one‑fourth three‑fourths

none

Which of the options are mechanisms of mRNA surveillance? premature‑termination mediation nonstop mRNA decay no‑go decay nonsense‑mediated mRNA decay tRNA mediated mRNA decay

nonstop mRNA decay no‑go decay nonsense‑mediated mRNA decay

A distinct clump of prokaryotic DNA observed via electron microscopy is referred to as a nucleus. nucleoid. nucleosome. nucleolus. plasmid.

nucleoid.

When two genes are linked but quite far apart, their estimated map distance, based on recombination frequencies, is often an underestimation of their true map distance. What is the explanation for this underestimation? Some double crossover events go undetected since they do not lead to recombinant progeny. One of the genes is lethal when homozygous which reduces the recombination frequency. The genes are located on different pairs of homologous chromosomes. There will be more single crossover events counted than actually have occurred so the recombination frequencies will be reduced. There will be few or no double crossovers occurring so that more nonrecombinant progeny are produced.

ome double crossover events go undetected since they do not lead to recombinant progeny.

The discovery that some proteins are composed of more than one polypeptide chain and that different polypeptide chains are encoded by separate genes became the research that revealed the process of translation. many genes, many polypeptides hypothesis. one gene, one polypeptide hypothesis. one protein, one polypeptide hypothesis. one gene, one enzyme hypothesis.

one gene, one polypeptide hypothesis.

A male with a rare autosomal dominant trait marries a phenotypically normal woman. What proportion of their children should show the trait? one‑fourth one‑half none three‑fourths all

one‑half

Which is not a characteristic of transposable elements? able to insert at many different locations throughout a genome can take place through a DNA intermediate in some cases only found in plants short flanking direct repeats present on both side of a transposon staggered breaks made in the target DNA during insertion

only found in plants

According to the biological species concept, what is the definition of a species? individuals occupying a single lineage in an evolutionary tree members from populations that share a similar appearance organisms that use the same niche in an environment organisms that can interbreed in nature to produce healthy offspring

organisms that can interbreed in nature to produce healthy offspring

In a __________,__________, environmental factors alone can produce a phenotype that is the same as the phenotype produced by a genotype. phenocopy compound heterozygote genetic maternal effect pleiotropy polygenic characteristic

phenocopy

Consider diagram C in Figure 8.3. What does the diagram represent? chromosome rearrangement polypoidy aneuploidy chromosome deletion

polypoidy

Which of the genes are specifically transcribed by eukaryotic RNA polymerase II? large rRNAs pre‑mRNAs tRNAs small rRNAs crRNAs

pre‑mRNAs

What changes does UV light produce in DNA molecules? purine dimers transversion mutations pyrimidine dimers deamination analog substitutions

pyrimidine dimers

Evolution of genes mostly seems to occur by point mutation and selection, whereas genome evolution seems to occur by all of the items except exon shuffling. horizontal gene transfer. random loss of chromosomes. whole genome duplication. gene duplication.

random loss of chromosomes.

The bacterial transfer‑messenger RNA system restores normal translation of the gene by a stalled ribosome. directly targets the mRNA with a stalled ribosome for degradation. generates truncated proteins. mediates the interaction of tRNAs with mRNA. removes stalled ribosomes in bacteria.

removes stalled ribosomes in bacteria.

Which of the proteins are directly responsible for ensuring that eukaryotic DNA is replicated precisely once in each round of replication, even though there are thousands of replication origins? single‑strand‑binding proteins DNA primase initiator protein replication licensing factor DNA polymerase δ

replication licensing factor

What is an Ab aB linkage arrangement called? coupling linkage interference complementation linkage disequilibrium repulsion linkage

repulsion linkage

Which mode of replication is unidirectional, antiparallel, continuous, and is initiated by a single break on the outer strand? rolling‑circle replication linear eukaryotic replication theta replication

rolling‑circle replication

A recessive mutant allele of an autosome gene in a species of mouse results in a shorted tail in males when homozygous. However, when homozygous in females, this genotype has no effect, and the mice have normal tails. What is this genetic phenomenon called? cytoplasmic inheritance genetic maternal effect sex‑influenced characteristic sex‑limited characteristic genomic imprinting

sex‑limited characteristic

Most bacterial RNA polymerases are made up of five subunits that have distinct functions for transcription. Which of the subunits does not permanently associate with the enzyme core? beta (β) alpha (α) sigma (σ) beta prime (β′) omega (ω)

sigma (σ)

Aminoacyl‑tRNA synthetases recognize their specific amino acid by and recognize the tRNAs that carry it by the

size, charge, and R group nucleotide sequence

Which RNA type is found only in eukaryotes? crRNA tRNA rRNA snoRNA mRNA

snoRNA

Which is a physical‑mapping technique that can be used to determine the human chromosome that contains a gene of interest? two‑point testcross analysis haplotype mapping linkage disequilibrium somatic‑cell hybridization genome‑wide association study

somatic‑cell hybridization

Additional copies of a gene ___ cause cellular problems. always never sometimes

sometimes

Which term describes the tertiary structural organization of chromosomal DNA that allows the long strand to be packed and fit into the cytoplasm of the cell? supercoiling centromere double helix telomere base pairing

supercoiling

Which enzyme is responsible for the replication of chromosome ends in germ cells and certain proliferating somatic cells? DNA polymerase δ telomerase topoisomerase DNA ligase geminin

telomerase

In experiments involving tobacco mosaic virus, Fraenkel-Conrat and Singer demonstrated that in some cases, both RNA and protein can be the genetic material. that in all cases, DNA is the genetic material. that in some cases, protein can be the genetic material. that in some cases, RNA can be the genetic material.

that in some cases, RNA can be the genetic material.

Multifactorial characteristics result from which of the statements? the activity of compound heterozygotes complementation between mutant alleles in different genes temperature‑sensitive alleles that are showing epigenetic expression the activity of polygenes influenced by environmental factors the activity of a gene locus where there are multiple alleles

the activity of polygenes influenced by environmental factors

A key discovery leading to the structure of DNA was done by Chargaff. He found that ____. Select all that apply. the tetranucleotide hypothesis was false the amount of A equals the amount of C, and the amount of G equals the amount of T the amount of A equals the amount of G, and the amount of C equals the amount of T the amount of A equals the amount of T, and the amount of G equals the amount of C

the amount of A equals the amount of T, and the amount of G equals the amount of C the tetranucleotide hypothesis was false

In the Hershey-Chase experiment, DNA was demonstrated to be the genetic material because the 32P label for DNA localized to the blender. the bacterial pellet. the bacterial pellet and the supernatant. the bacteriophage coats. the supernatant.

the bacterial pellet.

With genetic maternal effect, the phenotype of an individual is determined by which of the statements? a combination of environmental factors and the genotype of the individual the nuclear genotype of the maternal parent the sex of the parent who transmits the gene to the individual cytoplasmic genes usually located in the mitochondria the sex of the individual with only one sex able to express the genotype

the nuclear genotype of the maternal parent

What is penetrance? a situation where an allele is only expressed in one sex and does not produce the same phenotype in the other sex a situation where the stronger or earlier expression of a genetic trait occurs in succeeding generations the percentage of individuals having a particular genotype who express the expected phenotype a situation where a trait is only expressed at a particular temperature the degree to which a trait is expressed

the percentage of individuals having a particular genotype who express the expected phenotype

In humans, what normally results in the male sexual phenotype? the presence of the SRY gene on the Y chromosome the presence of the Xist gene on the X chromosome the presence of only one X chromosome (XO) the presence of one X chromosome and one W chromosome (XW) the presence of two Z chromosomes (ZZ)

the presence of the SRY gene on the Y chromosome

What did Griffith discover with his experiments? that bacteria can infect mice that DNA is the genetic material the transforming principle in bacteria that the genetic material contains acidic and phosphate groups that protein is the genetic material

the transforming principle in bacteria

The number of hydrogen bonds between complementary G−CG−C pairs is zero. two. three. four. one.

three

Which option is not a physical mapping technique? DNA sequencing fluorescence in situ hybridization deletion mapping somatic‑cell hybridization three‑point testcross

three‑point testcross

The compound camptothecin and its derivatives are used as effective chemotherapeutic drugs for treating cancer. Which enzyme is the target of camptothecin for disruption of DNA replication in cancer cells? DNA ligase DNA polymerase δ topoisomerase I replication licensing factor DNA primase

topoisomerase I

Which item contains the TATA‑binding protein (TBP)? Rho complex bacterial RNA polymerase transcription factor TFIID sigma subunit Rut enzyme

transcription factor TFIID

What types of proteins recognize and bind to eukaryotic upstream regulatory promoter consensus sequences? sigma subunits transcriptional activator proteins RNA polymerase III All of these proteins can bind to the regulatory promoter sequences. Rut proteins

transcriptional activator proteins

Barbara McClintock is known for her discovery of the Ames test. intercalating agents. base analogs. transposons. tautomers.

transposons.

In Avery, MacLeod, and McCarty's experiments, homogenates from heat‑killed bacteria were treated with different enzymes, and then the ability of those homogenates to transform bacteria was assayed. Under which condition would transformation not occur? treatment with DNase treatment with RNase and protease treatment with RNase treatment with protease

treatment with DNase

Of all cases of primary Down syndrome, 92% is due to of Chromosome 21. trisomy monosomy tetrasomy nullisomy

trisomy

mtDNA and cpDNA contain rRNA and tRNA genes of their own for their organelle‑specific functions. false true

true

Which of the mechanisms is not a mechanism of action of RNA inference? transcriptional silencing cleavage of mRNA inhibition of translation ubiquitination of proteins degradation of mRNA

ubiquitination of proteins

What disease occurs as a result of mutations in the genes for DNA repair systems? Huntington's disease fragile X syndrome glaucoma xeroderma pigmentosum sickle cell anemia

xeroderma pigmentosum

Which of the statements correctly describes the neutral‑mutation hypothesis? It proposes that natural selection does not occur. It proposes that much molecular variation is adaptively neutral. It focuses on chromosome mutations only. It states that natural selection increases variation. It states that mutations cannot have an effect on the fitness of an organism.

It proposes that much molecular variation is adaptively neutral.

Which statement about RNA is not true? RNA is a more stable molecule than DNA. RNA is thought to have dominated early life on earth, serving as both genetic information and as a catalyst. RNA possesses catalytic activity, which earned it the name "ribozyme." RNA typically consists of a single polynucleotide strand with distinct secondary structures. Uracil is found in RNA as one of the two pyrimidine nitrogenous bases.

RNA is a more stable molecule than DNA.

Which reaction normally happens in the regulation of the trp operon when high levels of tryptophan are present? Regions 2 and 4 will pair in the attenuation region in the 5′' UTR of the RNA. Regions 3 and 4 will pair in the attenuation region in the 5′ UTR of the RNA. The trp repressor will become inactivated. Regions 2 and 3 will pair in the attenuation region in the 5' UTR of the RNA. The trp activator protein will be produced.

Regions 2 and 4 will pair in the attenuation region in the 5′' UTR of the RNA.

How do response elements work to regulate transcription? They only function as a result of hormone signaling. They are specific to a certain gene and only respond to one stimulus. They are binding sites for transcriptional activators in response to stimuli. They are transcriptional activators that increase transcription in response to stimuli. They are binding sites for transcriptional repressors in response to stimuli.

They are binding sites for transcriptional activators in response to stimuli.

A liger is the hybrid offspring of a male lion and a female tiger, and a tigon is the hybrid offspring of a male tiger and a female lion. They are distinct from one another in appearance, and both are typically infertile. Select the most likely explanation as to how a female liger could be fertile and produce viable offspring. Genome duplication generates homologous pairs, so equal segregation can occur in meiosis. Unequal germline meiosis yields gametes with a haploid set of only tiger or lion chromosomes. Parthenogenesis occurs in an unfertilized oocyte. & If the fertile female liger was mated to a male tiger, what would the offspring resemble and why? would resemble a tiger because the male tiger contributes a full set of tiger chromosomes would resemble a tigon or a tiger because the mother can contribute only lion or only tiger chromosomes would resemble a liger because the mother is a liger and contributes her liger mitochondrial genome

Unequal germline meiosis yields gametes with a haploid set of only tiger or lion chromosomes. would resemble a tigon or a tiger because the mother can contribute only lion or only tiger chromosomes

Traditional analysis of mutants (natural or induced) to determine gene function is known as molecular genetics. forward genetics. transmission genetics. reverse genetics. functional genetics.

forward genetics.

When mRNAs are being translated simultaneously by multiple ribosomes, the structure is known as a(n) copolymer. polycistron. polyribosome. operon. polytene.

polyribosome.

You discovered a mouse gene with an unknown function. You do not know the location or sequence of this gene in the mice genome, but a similar gene has been isolated and sequenced in yeast. How might you determine whether this gene is essential for development in mice? Create a targeting vector using a cloned copy of the gene to develop a knockout mouse. If the gene is essential for development, no offspring heterozygous for the knockout will be born. Engineer a transgenic mouse that overexpresses this gene. If the gene is essential for development, no offspring will be born from the transgenic mice. Transform a yeast strain deficient for this gene with DNA fragments from a mouse genomic library to determine if a mouse clone can complement the yeast defect. Create a targeting vector using a cloned copy of the gene to develop a knockout mouse. If the gene is essential for development, no offspring homozygous for knockout will be born. Insert a cloned copy of this gene into the yeast genome. If yeast have the same phenotype as mice, the gene must be essential for development in mice.

Create a targeting vector using a cloned copy of the gene to develop a knockout mouse. If the gene is essential for development, no offspring homozygous for knockout will be born.

Plasmids are small circular DNA molecules found in bacteria that replicate separately from chromosomes. Why are plasmids essential for recombinant DNA technology? Plasmids provide the enzymatic action required to denature a molecule of DNA from a gene of interest that can be used in recombinant DNA technology. Plasmids can cleave the bonds between DNA strands in DNA molecules in a staggered manner, creating single‑stranded, "sticky" ends of DNA where the gene of interest can attach. Plasmids are able to rapidly reproduce exact copies of cells, so they provide a means to acquire a large number of cells that contain a particular gene of interest. DNA from a gene of interest can be inserted into a plasmid, then the modified plasmid can be inserted into a bacterial cell to replicate a gene of interest many times.

DNA from a gene of interest can be inserted into a plasmid, then the modified plasmid can be inserted into a bacterial cell to replicate a gene of interest many times.

Based on the information provided in the figure, choose whether introns or 3' untranslated regions (UTR) of a gene have higher rates of nucleotide substitution and the reason why. Introns have higher rates of substitutions because the introns do not code for protein. The 3' UTR may be translated, so there is a functional constraint on substitutions. Both should have approximately the same substitution rates, since both introns and the 3' UTR are noncoding regions of the gene. The 3' UTR of a gene has a higher rate of nucleotide substitution, since they mutate rapidly through the process of exon shuffling. Introns have higher rates of substitutions, since the introns do not code for protein. The 3' UTR of a gene may have a functional role in regulating mRNA stability and translation.

Introns have higher rates of substitutions, since the introns do not code for protein. The 3' UTR of a gene may have a functional role in regulating mRNA stability and translation.

What is the function of lacI in the regulation of the lac operon? It encodes a repressor that, in the presence of lactose, binds to the lac operator and blocks expression of the structural genes. It is the promoter that mediates the transcription of the operon. It is the operator that mediates the transcription of the structural genes. It encodes a repressor that, in the absence of lactose, binds to the lac operator and blocks expression of the structural genes. It is a structural gene that encodes permease.

It encodes a repressor that, in the absence of lactose, binds to the lac operator and blocks expression of the structural genes.

A diagram of the evolutionary relationships between organisms is known as a phylogeny, or phylogenetic tree. Which of the statements about the construction of phylogenies is not true? It can be based on fossil data. It reflects hierarchical classification of organisms. It is based on a direct observation of historical events. It can be based on DNA data. It depends on the use of homology.

It is based on a direct observation of historical events.

Determine the most likely reason why natural selection may cause prezygotic reproductive isolating mechanisms to evolve if postzygotic reproductive isolating mechanisms are already present, but natural selection can never cause the evolution of postzygotic reproductive isolating mechanisms. Natural selection may lead to the evolution of prezygotic reproductive isolation in organisms that already have postzygotic isolation to prevent wasted reproductive effort. Prezygotic isolation can evolve if postzygotic isolation has generated genetic variation during earlier periods of anagenesis. Prezygotic reproductive isolating mechanisms are the necessary physiological and behavioral precursors for the evolution of postzygotic isolation via natural selection. If postzygotic isolation is present, then natural selection is already acting on the same suite of traits that may lead to evolution of prezygotic isolation.

Natural selection may lead to the evolution of prezygotic reproductive isolation in organisms that already have postzygotic isolation to prevent wasted reproductive effort.

In plants, an increase in ploidy is one common mechanism of evolution. How does an increase in ploidy contribute to evolution? New species always arise when a haploid gamete fuses with a diploid gamete. All copies of the genes found in polyploids gain a new function. Sterile allopolyploids commonly pass down novel genes that evolve. New species can arise from crosses between two diploids followed by chromosome doubling. & Which statements address why polyploidy is more common in plants than in animals? Self‑fertilization in plants allows new polyploids to mate with themselves. Polyploid plants are always fertile, whereas polyploid animals are sterile. The process of cell division is more precise in animals than in plants. Behavioral isolation mechanisms prevent different animal species from interbreeding. Genome duplications, which result in polyploidy in plants, do not occur in animals.

New species can arise from crosses between two diploids followed by chromosome doubling Behavioral isolation mechanisms prevent different animal species from interbreeding. Self‑fertilization in plants allows new polyploids to mate with themselves.

The three‑spined stickleback is a fish often found in freshwater lakes with or without larger, predatory fish. In lakes with predatory fish, nearly all three‑spined sticklebacks have a complete pelvis with sharp spines. In lakes that lack predatory fish, there is wide phenotypic variation in skeletal structure, ranging from a fully intact pelvis with typical spines to the complete loss of the pelvis. Intermediates occur with a partial pelvis and no spines. Numerous nonsynonymous polymorphisms affecting pelvic development are responsible for phenotypic variation in lakes lacking predatory fish. Choose a likely explanation for differences in the prevalence of polymorphisms in each environment. In lakes lacking predatory fish, genetic drift increases stickleback genetic diversity because all fish are expected to occur in low numbers in these lakes. In lakes with predatory fish, Hardy-Weinberg equilibrium keeps gene frequencies constant and maintains diversity. The sticklebacks in environments with predatory fish have a shorter life span than sticklebacks in other lakes. A longer life allows for more mutations to accumulate in sticklebacks in lakes lacking predatory fish. The accumulation of somatic mutations over time accounts for the greater number of polymorphisms. The presence of large predatory fish has caused disruptive selection in sticklebacks, stimulating diversification in a population previously adapted to the absence of predators. In the absence of predatory fish, stabilizing selection occurs, and the sticklebacks in these populations lose part or all of the pelvis. Purifying selection acts on sticklebacks in lakes with predatory fish. Since spines deter large predators, individuals without spines are at a disadvantage. Conversely, sticklebacks in lakes lacking fish predators undergo positive adaptive selection because the lack of a pelvis conserves energy.

Purifying selection acts on sticklebacks in lakes with predatory fish. Since spines deter large predators, individuals without spines are at a disadvantage. Conversely, sticklebacks in lakes lacking fish predators undergo positive adaptive selection because the lack of a pelvis conserves energy.

A scientist studying vertebrate development performs a chemical mutagenesis screen in zebrafish. The mutagenesis screen identified 200 genes involved in development. How does a mutagenesis screen help scientists understand vertebrate development? Scientists can determine how closely genes are linked and allows the generation of genetic linkage maps. Scientists can determine the mode of inheritance of genes involved in vertebrate development by tracing mutant gene transmission. Scientists can understand a gene's normal function by evaluating alterations in vertebrate development when a mutant gene is present Scientists can identify frequently inherited polymorphic alleles involved in vertebrate development.

Scientists can understand a gene's normal function by evaluating alterations in vertebrate development when a mutant gene is present

Which statement is not a characteristic of transcriptional activator proteins? They can interact with other components of the transcriptional apparatus. They are capable of binding DNA at a consensus sequence of a regulatory promoter. They can influence the rate of transcription. They are capable of binding DNA at a consensus sequence in the protein‑coding part of the gene. They contain one or more DNA‑binding motifs.

They are capable of binding DNA at a consensus sequence in the protein‑coding part of the gene.

What is the basal transcription apparatus? a complex of DNA polymerase, TATA boxes, and the DNA sequence a complex of DNA polymerase, transcription factors, and other transcription proteins a complex of RNA polymerase, transcription factors, and other transcription proteins a complex of RNA polymerase, translation factors, and other translation proteins a complex of RNA polymerase, core promoters, and regulatory promoters

a complex of RNA polymerase, transcription factors, and other transcription proteins

What is a multigene family? a group of genes in one genome related by descent from a common ancestral gene a group of genes in different organisms related by descent from common ancestral gene a group of genes that can provide the same function through complementation a group of genes in close proximity to each other on the same chromosome What processes produce multigene families? exon exchange between different genes, creating new mosaic genes DNA transfer between individuals of different species, increasing relatedness gene duplication and divergence to produce different related products exon duplication and divergence to produce different related products

a group of genes in one genome related by descent from a common ancestral gene gene duplication and divergence to produce different related products

Which option matches the modification of histones with the correct effect on the histone? methylation of H3K4; represses transcription acetylation of histones by acetyltransferase; represses transcription acetylation of histones; stimulates transcription methylation of histones; stimulates replication deacetylation of histones by deacetylase; stimulates transcription

acetylation of histones; stimulates transcription

the Northern spotted owl and Mexican spotted owl arose from geographically isolated populations of the same ancestral owl species. The geographic ranges of the Northern spotted owl and the Mexican spotted owl are shown in the image. The evolution of the Northern spotted owl and Mexican spotted owl is an example of which type of speciation? peripatric speciation reproductive isolation allopatric speciation sympatric speciation

allopatric speciation

Which form of gene regulation primarily occurs in eukaryotes? All of these forms of regulation occur equally in both prokaryotes and eukaryotes. alteration of chromatin structure regulation of transcription regulation of mRNA stability regulation of translation

alteration of chromatin structure

Suppose a scientist wants to clone the gene for human insulin. He uses a plasmid that contains the lacZ gene, an origin of replication, and an ampicillin resistant gene. He inserts the human insulin gene into a restriction site located within the lacZ gene. Then he transforms this plasmid into bacteria without a functional lacZ gene and spreads the appropriate dilution onto bacterial plates. When the product of the lacZ gene, beta‑galactosidase, interacts with the subtrate X‑Gal on LB agar, colonies turn blue. Which plate indicates that the human insulin gene was successfully inserted in the plasmid? an LB agar plate with ampicillin and X‑Gal that produces blue colonies LB agar plate with X‑Gal that produces colorless colonies LB agar plate that produces colorless colonies LB agar plate with ampicillin and X‑Gal that produces colorless colonies

an LB agar plate with X‑Gal that produces colorless colonies

Biotechnology applications include all of the choices except genetic testing for people. artificial selection for larger fruit size in crops. All of the applications listed are biotechnology applications. transgenesis to produce pest‑resistant crops. gene therapy to treat genetic disorders.

artificial selection for larger fruit size in crops.

Suppose a scientist is studying the platypus, one of the few venomous mammals. The male platypus produces venom in the crural glands located beneath the calcaneus spur on each of its hind limbs. The female platypus can develop calcaneous spurs, but the crural glands never develop. Which of the following libraries would be most useful to help the scientist identify the gene or genes responsible for venom production? genomic DNA library generated from a mixture of different male platypus tissues cDNA library generated from mRNA isolated from a mixture of different male platypus tissues cDNA library made from the mRNA isolated from the crural gland of a male platypus genomeic DNA library generated from the crural gland of a female platypus genomic DNA library generated from the crural gland of a male platypus

cDNA library made from the mRNA isolated from the crural gland of a male platypus

After separating a complex mixture of DNA fragments according to size, identifying a specific fragment of interest can be accomplished by Northern blotting. requires a probe that is complementary to the entire fragment of interest. requires an antibody. can be accomplished by Southern blotting. is done on an electrophoretic gel directly.

can be accomplished by Southern blotting.

Restriction endonucleases have no specific sequence requirements for recognition or cutting. are used in standard DNA sequencing reactions. can be used to create pieces of DNA with cohesive ends. are used to cut RNA at defined sequences. were identified as a protozoan defense mechanism against viruses.

can be used to create pieces of DNA with cohesive ends.

Sympatric speciation only results in sterile hybrids, not in new species. needs a geographic barrier. does not produce different species. was the mode of speciation for Darwin's finches. can occur by polyploidy, wherein a sterile hybrid doubles its chromosome set.

can occur by polyploidy, wherein a sterile hybrid doubles its chromosome set.

Human α‑globin and β‑globin genes evolved through intron shuffling. horizontal gene transfer. exon shuffling. genome duplication. gene duplication.

gene duplication.

According to the biological species concept, which mechanism is not a mechanism of reproductive isolation? behavioral isolation prezygotic isolation geographic isolation ecological isolation postzygotic isolation

geographic isolation

Which item is a common DNA‑binding motif? iron‑finger helix‑turn‑helix loop‑helix‑loop ring‑loop‑ring alanine zipper

helix‑turn‑helix

Cloning a gene after isolating it requires which actions? Select all that apply. identification of the transformants that have the gene of interest transformation of the recipient cells with the vector with the gene of interest use of a virus to amplify the cloned gene DNA ligation into a vector expression of the protein in mammalian cells

identification of the transformants that have the gene of interest ligation into a vector transformation of the recipient cells with the vector with the gene of interest

A mutation in the lac promoter region that causes this region to no longer function would lead to lack of expression of the lac structural genes in the presence of lactose. expression of the lac structural genes in the absence of lactose. expression of the lac structural genes in the presence of lactose. enhanced initiation of transcription of the structural genes. overexpression of the lac structural genes.

lack of expression of the lac structural genes in the presence of lactose.

A biotechnology firm wants to produce a strain of giant Drosophila so that genetics students do not strain their eyes looking at tiny flies. A hormone called shorty substance P (SSP) normally inhibits growth in the flies. The enzyme runtase synthesizes SSP from the compound XSP in a single‑step catalytic reaction. A researcher isolated and sequenced runtase cDNA, but the researcher does not know the location of the runtase gene in the Drosophila genome. Initial attempts to delete, inactivate, or otherwise mutate this gene failed. Therefore, the researcher tries gene augmentation, or adding new genes to a cell. Which gene augmentation method could produce giant flies? insert a gene that expresses dsRNA for SSP, which would invoke the RNAi pathway and shut down SSP expressioninsert insert a gene that expresses high amounts of XSP, which would inhibit runtase insert a gene that expresses dsRNA for runtase, which would invoke the RNAi pathway and shut down runtase expression increase runtase gene expression to increase SSP production create transgenic flies that express high levels of SSP

nsert a gene that expresses dsRNA for runtase, which would invoke the RNAi pathway and shut down runtase expression

In protein‑coding genes, all nucleotide changes in a single gene are equally common. nucleotide changes at the first position of a codon are more common. nucleotide changes at the third position are least common. nucleotide changes at the third position of a codon are more common. nucleotide changes at the second position of a codon are most common.

nucleotide changes at the third position of a codon are more common.

Which items are used as cloning vectors? Select all that apply. ribosomes plasmids artificial chromosomes schistosomes cosmids

plasmids artificial chromosomes cosmids

A powerful genetic engineering technique used for the amplification of sequences of DNA is ligation‑based amplification (LBA). restriction fragment length polymorphism (RFLP) analysis. chromatin immunoprecipitation (ChIP). polymerase chain reaction (PCR). reverse transcription chain amplification (RTCA).

polymerase chain reaction (PCR).

Which choice is not a mechanism of gene regulation that can take place after transcription is completed in eukaryotes? RNA interference mRNA degradation RNA cleavage by siRNA polymerase stalling RNA splicing

polymerase stalling

If researchers have not yet isolated the protein product of a gene, what method can they use to isolate that gene? restriction enzyme digestion followed by gel electrophoresis positional cloning use of the CRISPR‑Cas9 system reverse transcription to make a cDNA library All the methods listed can be used.

positional cloning

Utilizing a genetic library requires all of the steps except All the steps listed are required when utilizing genetic libraries. screening the library with a probe for a gene of interest. cloning a large number of DNA fragments including the one of interest. positional cloning. transforming cells so that, in the pool of cells, all genes are represented.

positional cloning.

The type of transcriptional control in operons in which a regulatory protein is an activator and stimulates transcription is called repression. attenuation. induction. negative control. positive control.

positive control.

The way that proteins fold into beta pleated sheets and alpha helices is dependent on their primary structure. tertiary structure. quaternary structure. peptide bonds. secondary structure.

primary structure.

How does the concept of molecular clocks contribute to addressing the question of genetic identity between different species? determines how long it takes for mRNA to be transcribed into a protein helps estimate time since species had a common ancestor identifies which species are closely related projects how long it will be until a species will diverge

projects how long it will be until a species will diverge

The diagram represents a transcription unit comprised of three critical regions: the promoter, the coding region, and the terminator. Which region would not be present in the final RNA transcript? terminator promoter coding region All three regions are transcribed into RNA.

promoter

In nature, the purpose of the CRISPR‑Cas system is to replace defective restriction enzyme activity in bacteria. allow a bacterium to incorporate a bacteriophage genome into its genome. protect eukaryotic cells from transposon activity. allow organisms to edit their own genomes. protect bacteria and archaea from invading DNA elements.

protect bacteria and archaea from invading DNA elements.

Reverse genetics attempts to determine the function of a gene by changing it, using all of the techniques except knockout. RNAi. knockdown. reverse transcription. site‑directed mutagenesis.

reverse transcription.

In Africa, Lake Victoria is home to many distinct species of cichlid fish that vary in color from blue to red. Cichlid fish species that live in shallow water are blue and prefer to mate with other blue fish, whereas cichlid fish species that live in deep water are red and prefer to mate with other red fish. All of the cichlid fish species evolved from a single ancestrial species and live together in the same habitat. The cichlid fish in Lake Victoria are an example of which type of speciation? adaptive radiation allopatric speciation parapatric speciation sympatric speciation

sympatric speciation

Which of these is not involved in the initiation of translation in bacteria? mRNA tRNA carrying N-formylmethionine that will occupy the P site small and large ribosomal subunits tRNA carrying the next amino acid that will occupy the A site GTP and initiation factors

tRNA carrying the next amino acid that will occupy the A site

What is the first stage of protein synthesis? initiation, in which the components necessary for translation are assembled at the ribosome setting the reading frame, where the initiation codon is recognized by RNA polymerase elongation, in which amino acids are joined to the polypeptide chain the assembly of transcription factors at the promoter tRNA charging, in which the tRNAs bind to amino acids

tRNA charging, in which the tRNAs bind to amino acids

Recombinant DNA technology is a set of molecular methods used to isolate, manipulate, and study DNA. What does recombinant mean, in this case? that the DNA used was edited using the CRISPR‑Cas system that the DNA used was cut with restriction enzyme or enzymes that the DNA used is often derived from two or more sources and combined that the DNA used does not contain introns that the DNA used has undergone homologous recombination

that the DNA used is often derived from two or more sources and combined

Which component of translation is frequently targeted by antibiotics? tRNAs IF‑2 the template mRNA the ribosome aminoacyl‑tRNA synthetase

the ribosome