Bio 311 Exam 3

c

During meiosis, errors can be made during chromosome replication. Which term describes a mutation where a chromosome breaks, and its genetic material is reinserted in a different orientation? a. frameshift b. duplication c. inversion d. isochromosome

a

During meiosis, errors occur during chromosome replication. Which term describes the addition of genetic material to a chromosome through extra replication of a chromosomal section? a. duplication b. isochromosome mutation c. nondisjunction d. translocation

a

During meiosis, errors occur during chromosome replication. Which term describes the rearranging of genetic material between nonhomologous chromosomes without a net loss of gain of genetic material? a. translocation b. crossing over c. frameshift d. inversion

b

A man has a large inversion on one of his chromosomes. How might this impact his offspring? a. extra sex chromosomes because normal synapsis during meiosis does not occur b. miscarriage or stillbirth caused by defective chromatids c. minor genetic abnormalities due to minimal deficiency in genetic material d. no impact because all genetic information is retained

a

About 0.3% of human live births are trisomic. In contrast, only 0.02% of human live births are monosomic. Select the best explanation for why the occurrence of trisomics is greater than that of monosomics. a. deleterious recessive alleles may be masked by dominant alleles on trisomic chromosomes but not on the monosomic chromosomes. b. mitosis is more likely to be completely correctly in trisomics than in monosomics c. gene dosage imbalance is less likely to lead to spontaneous abortion in trisomics than in monosomics d. meiotic nondisjunction more commonly results in trisomic gametes than in monosomic gametes

c

According to the central dogma, double-stranded DNA serves as the template for the production of RNA during transcription. Which of the two DNA strands serves as the template for transcription. a. The DNA strand oriented in the 5'-3' direction os the only template because only this strand contains the polymerase binding sequences necessary to initiate transcription. b. Both DNA strands serve as templates simultaneously for RNA polymerase, with continuous transcription on the leading strand and discontinuous transcription on the lagging strand. c. Either DNA strand may be used as a template by RNA polymerase, but a single DNA strand oriented in the 3'-5' direction is used as a template each time transcription occurs. d. The DNA strand oriented in the 5'-3' direction is the only template because RNA polymerase synthesizes only in the 5'-3' direction.

cbade

Arrange the events of gene conversion of wild type allele R to mutant allele r during meiotic recombination. recombination in meiosis _ _ _ _ _ gene conversion a. mismatch bases are excised from the R allele b. mismatched bases in the heteroduplex trigger mismatch repair c. a heteroduplex is formed between R and r alleles d. gaps in the R allele sequence are filled by copying the r allele e. the wild type R allele is converted to the mutant r allele

ceabd

Arrange the features of eukaryotic chromosome packaging in order from the smallest unit to the largest unit. _ _ _ _ _ a. coiled fiber b. chromosome c. nucleotide d. genome e. nucleosome

bdcfae

Arrange the steps of DNA replication in the order that they occur. first step _ _ _ _ _ _ last step a. RNA primers are removed b. helicase unwinds the DNA double helix c. RNA primers are added d. single-stranded DNA-binding proteins bind to each template strand e. DNA ligase joins DNA fragments together f. DNA polymerase synthesizes DNA

a

As DNA is replicated, both continuous and discontinuous replication occur. Discontinuous replication is the result of which specific feature of DNA? a. antiparallel strands b. minor groove c. purine and pyrimidine nucleotides d. action of helicase at the replication fork e. covalent bonds

aecbfdg

At least three types of RNA are required for protein synthesis. Compare and contrast mRNA, rRNA, and tRNA by moving the descriptions of their structure and function to the appropriate categories. Some phrases may describe all three types of RNA. mRNA: _ _ rRNA: _ tRNA: _ _ all three: _ _ a. moves genetic information out of the nucleus and into the cytoplasm b. moves amino acids to the site of protein synthesis c. acts as an enzyme for peptide synthesis d. in eukaryotes can exist outside the nucleus e. contains nucleotide triplets that code for specific amino acids f. has a convulted structure with a three-base sequence called an anticodon g. composed of ribonucleic acid

bcad

Classify each description as applying to either heterochromatin or euchromatin. Heterochromatin: _ _ Euchromatin: _ _ a. the expanded form of chromatin b. the highly compressed form of chromatin c. the type of chromatin that is not usually transcribed d. the type of chromatin that is most often transcribed

cdbea

Classify each description to the appropriate category. transcription: _ _ replication: _ _ both: _ a. localized in the nucleus in eukaryotic cells b. RNA primase is required c. acts on only one strand d. catalyzed by RNA polymerase e. catalyzed by DNA polymerase

adfgbceh

Classify each feature as describing prokaryotic DNA structure or eukaryotic DNA structure. Prokaryotic DNA structure: _ _ _ _ Eukaryotic DNA structure: _ _ _ _ a. DNA is circular b. DNA is linear c. condensed around histone proteins d. condensed only by DNA supercoiling e. arranged in multiple chromosomes f. arranged in a single looped structure g. does not have telomere region h. has repeating telomere region

bdceafh

Classify each of the descriptions as a characteristic of mitochondria only, chloroplasts only, or both mitochondria and chloroplasts mitochondria only: _ _ chloroplasts only: _ _ both mitochondria and chloroplasts: _ _ _ a. contain DNA b. contain cristae c. contain grana d. perform cellular respiration e. perform photosynthesis f. produce energy h. mobile within the cell

abcdbed

Complete the sentences about DNA packaging. Some terms may be used more than once. 1. The less condensed form of chromatin is _ . 2. The inactive form of chromatin is _. 3. A core composed of _ proteins interacts with DNA through hydrogen bonding and ionic bonds. 4. If DNA structure is described as "beads-on-a-string," a "bead" is a _. 5. The more darkly-staining form of chromatin is _. 6. If DNA structure is described as "beads-on-a-string," a "string" is the _. 7. A _ is a DNA-protein complex. a. euchromatin b. heterochromatin c. histone d. nucleosome e. dna molecule

aacbdd

Complete the sentences. Each term may be used more than once. 1. In a circular bacterial chromosome, the structure of DNA is a _ double helix. 2. If DNA is twisted in the _ direction, it becomes overwound. 3. Overwinding results in _ supercoiling. 4. If DNA is twisted in the _ direction, it becomes underwound. 5. Underwinding results in _ supercoiling. 6. One effect of _ supercoiling in bacterial chromsomes is to promot separation of the two strands of DNA in the double helix. a. right-handed b. left-handed c. positive d. negative

cfabde

DNA encodes the cell's genetic instructions for making proteins. The process of making proteins from DNA is divided into two stages called trasncription and translation. Transcription is further divided into three steps called initiation, elongation, and termination. Classify the statements about transcription according to the step in which each occurs. initiation: _ _ elongation: _ termination: _ _ _ a. The RNA polymerase traverses the DNA template, adding complementary base pairs in the 5' to 3' direction. b. The RNA polymerase detaches from the DNA. c. The RNA polymerase binds to the group of transcription factors at the promoter. d. The RNA polymerase stops adding base pairs when it reaches a cetain DNA sequence that signals the end of the gene. e. The RNA trasncript is released. f. The DNA double helix unwinds and RNA synthesis begins.

d

DNA is wrapped around histone proteins and coiled to form a dense fiber called chromatin. Which statement describes the function of the chromatin conformation of DNA? a. the condensed DNA in chromatin is transported out of the nucleus b. chromatin allows DNA to interact with replication machinery c. single- stranded DNA can be stored in the nucleus as chromatin d. DNA is wrapped around histone proteins to condense and organize DNA

ACTGCACTA

Enter the complementary sequence to the DNA strand shown. 5'-TGACGTGAT-3' 3'- ________-5'

c

Histone proteins... a. enable mitochondrial DNA to replicate with nuclear DNA before mitosis b. organize DNA into separate chromosomes at the beginning of mitosis c. attach to DNA and form compacted DNA- protein associations d. release bound DNA to enable nuclear division during mitosis

a

How does chromosome compaction differ during metaphase and interphase in eukaryotes? a. chromosomes are less compacted in interphase than in metaphase b. there is no chromosome compaction in interphase c. maximum chromosome compaction occurs during interphase d. chromosomes are more compacted in interphase than in metaphase

bd

Identify the functions of an enhancer in transcription. (select) a. inhibits trasncription by binding to the operator b. a cis-regulatory element that increases gene transcription in specific tissues or cells c. a cis-acting regulatory sequence of DNA that reduces levels of transcription d. regulates transcription by providing a clushter of binding sites where transcription factors can bind e. begins gene expression by binding to and disabling repressors

bce

Identify the statements that are features of a promoter. (select) a. in eukaryotes, the promoter attracts the small and large ribosomal subunits with the help of initiation factors b. in eukaryotes, the promoter often contains a TATA box, which is where the TATA-binding protein binds c. in both prokaryotes and eukaryotes, the promoter is located in the 5' direction, upstream from the transcription start site d. in eukaryotes, the promoter is recognized by a sigma factor subunit which must bind to the promoter before forming the preinitiation complex e. in prokaryotes, the promoter contains a -35 and -10 region upstream of the transcription start site

abde

In 1953, the scientists JAmes Watson and Francis Crick published their landmark findings on the structure of DNA. Watson and Crick deduced the structure of DNA by unifying evidence that they collected from several scientists who were also seeking to answer this important question. Identify the pieces of evidence describing the features of DNA that Watson and Crick used to determine the structure of DNA. (select) a. A purine base forms hydrogen bonds to pair with a pyrimidine base located on the opposite DNA strand. Speciifically, A pairs with T, and C pairs with G. b. The sugar-phosphate backbones of each DNA helix run antiparallel to one another. c. The two chain are parallel, both running in a 5' to 3' direction. d. The diameter of the DNA double felix is 2 nanometers, with each purine-pyrimidine base pair spanning an equivalent distance between the two chains. e. DNA forms a right-handed double helical structure with two polynucleotide chains coiled around a central axis. f. A purine base forms covalent bonds with a pyrimidine base located on the oppposite DNA helix.

c

In 1979, bones found outside Ekaterinburg, Russia, were shown to be those of Tsar Nicholas and his family, who were executed in 1918 by a Bolshevik firing squad in the Russian Revolution. To prove that the skeletons were those of the royal family, mtDNA was extracted from the bone samples, amplified by PCR, and compared with mtDNA from living relatives of the tsar's family. From which living relatives would mitochondrial DNA provide useful information for verifying that the skeletons were those of the royal family? a. the mtDNA from the tsar's living relatives of paternal descent should be analyzed b. the mtDNA from the tsar's living relatives of both paternal and maternal descent should be analyzed c. the mtDNA from the tsar's living relatives of maternal descent should be analyzed

ac

In 1979, bones found outside Ekaterinburg, Russia, were shown to be those of Tsar Nicholas and his family, who were executed in 1918 by a Bolshevik firing squad in the Russian Revolution. To prove that the skeletons were those of the royal family, mtDNA was extracted from the bone samples, amplified by PCR, and compared with mtDNA from living relatives of the tsar's family. Select options indicating why DNA from the mitochondria analyzed instead of nuclear DNA. (select) a. mitochondrial genomes are present in multiple copies in the cells b. mitochondiral DNA is inherited from both parents c. mitochondrial DNA does not undergo recombination d. mitochondrial DNA is circular and is more stable over time

dacb

In eukaryotes, different groups of proteins regulate transcription initiation. Classify each of the transcription-associated proteins and protein componenets according to its role in transcription. initiates transcription: _ increases transcription: _ _ decreases transcription: _ a. activator b. repressor c. enhanceosome d. pre-initiation complex

cd

Nalidixic acid is an antibiotic that inhibits DNA synthesis by preventing the action of DNA gyrase. DNA gyrase introduces negative supercoils into DNA. Which statements explain why inhibiting negative supercoiling in bacteria inhibits overall bacterial growth? (select) a. negative supercoiling results in overwound supercoils that initiate DNA synthesis b. negative supercoiling decreases chromosome compaction, which increases DNA synthesis in bacteria c. negative supercoiling is necessary for the binding of DnaA to the origin of replication d. negative supercoiling aids in chromosome compaction, which ensures the transmission of chromosomes to daughter cells e. negative supercoiling increases the size of the chromosome, making it easier to replicate

ab

Lesch-Nyhan syndrome is an X-linked, recessive condition caused by mutation of the HPRT1 gene responsible for purine metabolism. The syndrome is characterized by juvenile-onset gout, involuntary muscle movements, and behavioral disorders. A mother and father have a young daughter who was diagnosed with Lesch-Nyhan syndrome. No one in the father's family was ever diagnosed with the syndrome. The mother's maternal grandfather was diagnosed with Lesch-Nyhan syndrome, but neither one of her parents was diagnosed with the condition. Select all the descriptions that could explain how their daughter inherited Lesch-Nyhan syndrome. (select) a. The mother's X chromosomes failed to separate during meiosis, and the daughter inherited two X chromosomes with the Lesch-Nyhan mutation. The father contributed no sex chromosomes. b. The father did not contribute a sex chromosome to his daughter due to nondisjunction of the sex chromosomes. The daughter is XO and her only X chromosome came from her mother, who was a carrier. c. The daughter could not have inherited Lesch-Nyhan because her maternal grandparents did not have the disease. The girl must have acquired the disease through a random mutation. d. The daughter is XO. Her only X chromosome carries the Lesch-Nyhan mutation and was inherited from her father, who was a carrier.

a

Many errors can occur during meiosis. Which term describes the process of sister chromatids not separating at the centromere during cell division? a. nondisjunction b. cytokinesis c. desegregation d. aneuploidy

cbad

Match each function to the appropriate type of RNA. mRNA: _ rRNA: _ tRNA: _ _ a. hydrogen bonds with codon b. enzymatic amide bond synthesis c. contains the codons for the polypeptide sequence d. transports amino acids to the ribosome

cab

Match the definitions to the appropriate terms that describe the number of chromosomes. tetraploid: _ tetrasomic: _ n=4: _ a. two extra copies of a specific chromosome b. a genome composed of four unique chromosomes c. four homologues of each chromosome

a

One example of non-Mendelian inheritance is uniparental inheritance. Choose the definition of uniparental inheritance. a. one parent transmits all genetic information to all offspring b. two parents transmit combined genetic information to half of their offspring c. one parent transmits all genetic material to only half of the offpsring d. two parents transmit combined genetic information to all offspring

bc

One example of non-Mendelian inheritance is uniparental inheritance. Select the examples of genetic material that are uniparentally inherited in sexually reproducing eukaryotes. (select) a. nuclear DNA b. mitochondrial DNA c. chloroplast DNA d. endoplasmic reticulum DNA

beafdc

Order the events in which telomerase maintains chromosomal ends during replication. first event _ _ _ _ _ _ last event a. telomerase moves along the newly synthesized DNA strand toward the 3' end. b. the RNA component of telomerase binds to a complementary sequence on the 3' G overhang of DNA c. synthesis occurs on the 5' end of the complementary strand of DNA to fill the gap created by telomerase d. telomerase is removed from the DNA strand entirely e. nucleotides that are complementary to the RNA component of telomerase are added to the 3' end of the DNA f. additional nucleotides are added to the 3' end of the DNA

bacedf

Place the steps of eukaryotic DNA replication in order, from when a germ cell enters gap 1 (G1) phase to the cell cycle termination. cell enters gap 1 _ _ _ _ _ _ cell cycle termination a. the initiation complex create an active replication fork as helicase unwinds DNA b. pre-replication complex forms at one of many origins of replication c. RNA primers are added to provide a 3' end for elongation d. RNA is replaced with DNA and lagging strands are joined e. 5' to 3' synthesis of the leading and lagging strands is carried out by DNA polymerase f. active telomerase can extend the lost telomere region

bdaecf

Place the steps of eukaryotic transcription in order of occurrence. RNA polymerase II binds DNA promoter element _ _ _ _ _ _ Processed mRNA leaves the nucleus a. RNA polymerase links triphosphate ribonucleotides together. b. RNA polymerase unwinds DNA. c. RNA polymerase is released from DNA. d. Ribonucleotides align with complemetary DNA nucleotides. e. Guanylyltransferase adds a guanine cap to the 5' end of the mRNA. f. The mRNA is polyadenylated and spliced.

acbed

Place the type of chromosomal mutation next to each set of chromosomes. The * represents the centromere. wild-type: AB*CDEFG chromosomal mutation 1: AB*CDEFDEFG _ chromosomal mutation 2: AB*DEFCDEFG _ chromosomal mutation 3: AB*CDE _ chromosomal mutation 4: AB*CGFED _ chromosomal mutation 5: AEDC*BFG _ a. tandem duplication of DEF b. deletion of FG c. displaced duplication of DEF d. pericentric inversion of BCDE e. paracentric inversion that includes DEFG

bcda

Place the type of translocation and sequence or sequences trasnlocated next to each set of chromosomes. nonhomologous chromosomes: AB*CDEFG RS*TUVWX translocation 1: AB*CD RS*TUVWXEFG translocation 2: AUVB*CDEFG RS*TWX translocation 3: AB*TUVFG RS*CDEWX tranlocation 4: AB*CWG RS*TUVDEFX a. reciprocal translocation of DEF and W b. nonreciprocal translocation of EFG c. nonreciprocal translocation of UV d. reciprocal translocation of CDE and TUV

d

Red-green color blindness is a human X-linked recessive disorder. The normal allele, X^B, is dominant to the mutant allele, X^b. Jill has normal color vision, but her father is color blind. Jill marries Tom, who also has normal color vision. Jill and Tom have a daughter who has Turner syndrome and is color blind. How and from whom did the daughter inherit color blindness? a. an ovum carrying X^B followed by fertilization by sperm from a paternal nondisjunction event b. a maternal nondisjunction followed by fertilization by sperm lacking sex chromosomes c. a maternal nondisjunction followed by fertilization by sperm carrying X^B d. an ovum carrying X^b followed by fertilization by sperm from a paternal nondisjunction event e. a maternal nondisjunction event followed by fertilization by sperm carrying X^b

c

Select the definition of aneuploidy. a. the number of chromosome sets that make up a complete genome b. a chromsomal complement with at least three complete sets of homologous chromosomes c. the addition or loss of less than a full set of chromosomes or chromosome pairs d. a complete chromosome set or an exact multiple of the haploid chromosome set

d

Select the definition of euploidy. a. the number of chromosome sets that make up a complete genome b. a chromsomal complement with at least three complete sets of homologous chromosomes c. the addition or loss of less than a full set of chromosomes or chromosome pairs d. a complete chromosome set or an exact multiple of the haploid chromosome set

b

Select the definition of polyploidy. a. the number of chromosome sets that make up a complete genome b. a chromsomal complement with at least three complete sets of homologous chromosomes c. the addition or loss of less than a full set of chromosomes or chromosome pairs d. a complete chromosome set or an exact multiple of the haploid chromosome set

d

Select the function of the centromere in the transmission of genetic information. a. the swelling of the cell in preparation for division b. the production of ribosomal subunits c. the replication of chromosomes d. the attachment point for sister chromatids e. the formation of the mitotic spindle

ace

Select the statements that describe the effect of copy number variation on human phenotypes. (select) a. increase in the copy number genes involved in starch digestion allows for a high-starch diet b. a decrease in copy number can cause Mendelian autosomal disorders due to point mutations c. copy number variations are associated with polygenic disorders such as schizophrenia d. an increase in copy number can cause gene function loss due to chromosome breaks e. oncogene overexpression due to a gain in copy number can cause cancer

abc

Select the statements that explain why duplication is a driving force for evolution and the generation of new genes. (select) a. duplicated genes provide extra copies of DNA that are not constrained by an essential function b. genes duplicate and then diverge from the original sequence to create multigene families c. phenotypic variations can occur when random fixed mutations are introduced into a new chromosomal environment d. duplication of a gene segment always results in novel gene functions

d

Some people with Turner syndrome are 45,X/46,XY mosaics. How could this mosaicism arise? a. a cell loses an X chromosome soon after fertilization in an XY embryo b. a cell gains a Y chromosome soon after fertilization in an XX embryo c. a cell loses a Y chromosome soon after fertilization in an XX embryo d. a cell loses a Y chromosome soon after fertilization in an XY embryo e. a cell gains an X chromosome soon after fertilization in an XY embryo

d

Suppose a scientist grows cells in a medium that contains amino acids labeled with a heavy isotope. She isolates histone octamers from some of these cells and subjects that isolated proteins to density-gradient centrifugation. The centrifugation yields a single band of heavy isotope-labeled histones near the bottom of the tube. The scientist then transfers the remaining cells to a medium that contains amino acids labeled with a light isotope. She isolates new histone octamers from the culture after cells replicate in this medium and subjects these proteins to another round of density-gradient centrifugation. How many bands does the scientist expect to see in the second round of density-gradient centrifugation if all original histone proteins remain on one strand of DNA and new histones attach to the other strand during replication? a. one band containing octamers composed of both original and new histones. b. one lower band containing the new histone octamers and one higher band containing the original histone octamers c. one lower band containing the original histone octamers, a middle band conatining octamers composed of both histone types, and a top band containing the new histone octamers d. one lower band containing the original histone octamers and one hgiher band containing the new histone octamers

c

The Meselson and Stahl experiment starts with E. coli containing 15N/15N labeled DNA grown in 14N media. Which result did Meselson and Stahl observe by sedimentation equilibrium centrifugation to provide strong evidence for the semiconservative model of DNA replication? a. Both the first and second generation have both 15N/15N DNA and 14N/14N DNA. No hybrid 15N/14N DNA was observed. b. The first generation has hybrid 15N/14N DNA and the second genertaion has hybrid 15N/14N DNA. No 15N/15N DNA nor 14N/14N DNA was observed. c. The first generation has hybrid 15N/14N DNA and the second generation has both hybrid NN DNA and 14N/14N DNA. No 15N/15N DNA was observed.

e

The antibiotics tetracycline and erythromycin inhibit bacterial protein synthesis, but have no effect on proteins enocded by eukaryotic, nuclear genes. Conversely, the antibiotic cycloheximide inhibits protein synthesis of nuclear genes, but has no effect on protein synthesis in bacteria. Select the statement that best describes the effect of a particular antibiotic on protein synthesis. a. cycloheximide treatment would inhibit expression of mitochondrial genes, but not expression of nuclear genes b. tetracycline treatment would inhibit translation of nuclear genes, but not translation of mitochondrial genes c. it cannot be determined because two of these antibiotics affect bacteria, and cells with mitchondrial genes d. erythromycin treatment would inhibit protein synthesis from nuclear genes, but not from mitochondrial genes e. tetracycline treatment would inhibit mitochondrial protein synthesis, but not protein synthesis of nuclear genes

bcade

The descriptions pertain to either prokaryotic or eukaryotic transcription. Match each description to the appropriate category. prokaryotic transcription: _ _ eukaryotic transcription: _ _ _ a. includes addition of 5' cap b. can be terminated by rho helicase c. promoter includes-10 consensus sequence d. requires TFIID e. promter includes a TATA box

GCAUAUGCGGUAC

The diagram represents DNA that is part of the RNA-coding sequence of a transcription unit. The botton strand is the template strand. 5'-GCATATGCGGTAC-3' 3'-CGTATACGCCATG-5' Give the sequence found on the RNA molecule that is transcribed from the above DNA molecule. 5'- _______-3'

bd

The end-replication problem (telomere problem) exists in eukaryotic chromosomes and is characterized by the chromosomes shortening with each round of DNA replication. Select the statements that best explain why the end-replication problem exists in eukaryotic chromosomes. (select) a. the RNA primer is removed in a 3' to 5' direction b. DNA polymerase requires a primer for DNA synthesis c. the lagging strand is synthesized from the 3' end to 5' end d. DNA polymerase synthesizes DNA from the 5' end to the 3' end e. DNA ligase links the 5'OH group of one fragment to the 3' phosphate group of an adjacent fragment

bce

Which relations will be found in the percentages of bases of a double-stranded DNA molecule? (select) a. A/G=C/T b. (A+G)/(C+T)=1.0 c. A+C=G+T d. A+T=G+C e. A/T=G/C

ab

The enzyme telomerase is part protein and part RNA. What would be the most likely effect of a large deletion in the gene that encodes the RNA part of telomerase, and how would the function of telomerase be affected? (select) a. telomerase would lose the ability to synthesize new telomeric sequences to extend the telomere b. telomerase would be unable to correctly associate with telomeres c. the telomerase enzyme would be able to make only a few telomeric repeats before falling off d. telomerase would be unstable to proofread its DNA product but would still synthesize telomeres e. the catalytic center of telomerase, the polmerase, would be altered

a

Two brothers hve X-linked red green colorblind vision, and their parents have normal color vision. The first brother's karyotype is 47, XXY (Klinefelter syndrome), and the second brother's karyotype is 46, XY. In which parent and in what cell division phase did the first brother's chromosomal nondisjunction occur? Assume no recombination. a. in the mother in meiosis II b. in either parent in somatic cell mitosis c. in the mother in meiosis I d. in the father in meiosis II e. in the father in meiosis I

c

What contribution did James Watson and Francis Crick make to our understanding of DNA? a. they determined that adenine and thymine occur in equal amounts in DNA b. they deduced that DNA, not protein, is used as the genetic code in living organisms c. they modeled the structure of DNA based on the limited data available d. they produced a clear X-ray diffraction picture of the three-dimensional structure of DNA

c

What happens during the elongation step of DNA transcription? a. the mRNA detaches from the RNA polymerase as the RNA polymerase leaves the DNA strand b. a ribosome attaches to the initiation codon of a completed mRNA strand c. RNA polymerase moves along the template strand of the DNA creating an mRNA strand d. a portion of the DNA unwinds and RNA polymerase attaches to the DNA within the transcription bubble

b

What happens during the initiation step of DNA transcription? a. a ribosome attaches to the initiation codon of a completed mRNA strand b. a portion of the DNA unwinds and RNA polymerase attaches to the DNA within the trasncription bubble c. RNA polymerase moves along the template strand of the DNA creating an mRNA strand d. the mRNA detaches from the RNA polymerase as the RNA polymerase leaves the DNA strand

b

What happens during the termination step of DNA transcription? a. a ribosome attaches to the initiation codon of a completed mRNA strand b. the mRNA detaches from the RNA polymerase as the RNA polymerase leaves the DNA strand c. a portion of the DNA unwinds and RNA polymerase attaches to the DNA within the transcription bubble d. RNA polymerase moves along the template strand of the DNA creating an mRNA strand

b

What is the role of the eukaryotic promoter in transcription? a. the origin of replication b. the site where transcription factors bind and function c. the complex that unwinds DNA for transcription d. the region removed during transcript splicing e. the site where transcription stops

a

Which of the following single-stranded DNA sequences is most likely to form a stem-loop structure? a. CAAGCGGCCGCGCTTG b. ATAAGATGGGAGCATG c. GCAGGGACTCCGACGT d. TCATAGGCGCCGTTCA

e

Which of the following statements describes the function of the sigma factor in prokaryotic transcription? a. it casues the RNA polymerase to dissociate from the mRNA to terminate transcription b. it catalyzes the synthesis of mRNA in a 5' to 3' direction to implement transcription elongation c. it catalyzes the splicing of the primary transcript to produce mature mRNA to terminate transcription d. it attaches the amino acid to its cognate tRNA to initiate translation e. it guides RNA polymerase to the promoter to initiate transcription

bcd

Which of the statements are true of endosymbiotic theory? (select) a. provides insight about why mitochondria can survive outside of a eukaryotic cell b. explains the origins of some eukaryotic organelles, such as chloroplasts c. explains why mitochondria contain their own genetic information d. states than an ancestral eukaryotic cell engulfed an aerobic protobacteria e. explains the origin of all organelles found within a eukaryotic cell

bd

Which of the statements describes purines and pyrimidines in DNA molecules? (select) a. pyrimidines form hydrogen bonds with pyrimidines b. purines consist of a two-ring structure c. thymine and cytosine are purines d. purines form hydrogen bonds with pyrimidines e. purines form covalent bonds with pyrimidines

bd

Which of these is an example of a sequence of bases in an RNA molecule that will produce a hairpin structure? (select) a. AAUAAUUUCGGAGCGC b. CGCGCAAAGCGCG c. AUCGGGCCCAAGUCG d. UGUGAUACUCAUCGCA e. TGCGATACTCATCGCA

c

Which statement best defines gene conversion? a. the homologous recombination between four strands of DNA b. the reciprocal exchange of genetic material between homologous chromosomes c. the recombination of genetic material between a locus on one chromosome and another homologous locus on a different, nonhomologous chromosome d. the insertion of an additional nucleotide base, resulting in a frameshift mutation