bio 1406 exam 4 questions

Which statement is true of viroids? a. They are single-stranded RNA particles. b. They reproduce only outside of the cell. c. They produce proteins. d. They affect both plants and animals

A. They are single-stranded RNA particles.

Which is true of DNA viruses? a. They use the host cell's machinery to produce new copies of their genome. b. They all have envelopes. c. They are the only kind of viruses that can cause cancer. d. They are not important plant pathogens.

A. They use the host cell's machinery to produce new copies of their genome.

Genomics can be used on a personal level to: a. decrease transplant rejection b. predict genetic diseases that a person may have inherited c. determine the risks of genetic diseases for an individual's children d. all of the above

A. decrease transplant rejection

Individual genetic maps in a given species are: a. genetically similar b. genetically identical c. genetically dissimilar d. not useful in species analysis

A. genetically similar

A scientist discovers a new virus with a linear, RNA genome surrounded by a helical capsid. The virus is most likely a member of which family based on structure classification? a. Rabies virus b. Herpesviruses c. Retroviruses d. Influenza viruses

A. rabies virus.

The chain termination method of sequencing: a. uses labeled ddNTPs b. uses only dideoxynucleotides c. uses only deoxynucleotides d. uses labeled dNTPs

A. uses labeled ddNTPs

Prokaryotic cells lack a nucleus. Therefore, the genes in prokaryotic cells are: a. all expressed, all of the time b. transcribed and translated almost simultaneously c. transcriptionally controlled because translation begins before transcription ends d. b and c are both true

B and C. transcribed and translated almost simultaneously. transcriptionally controlled because translation begins before transcription ends.

which statement is true of viral replication? a. In the process of apoptosis, the cell survives. b. During attachment, the virus attaches at specific sites on the cell surface. c. The viral capsid helps the host cell produce more copies of the viral genome. d. mRNA works outside of the host cell to produce enzymes and proteins.

B. During attachment, the virus attaches at specific sites on the cell surface.

What is a biomarker? a. the color coding of different genes b. a protein that is uniquely produced in a diseased state c. a molecule in the genome or proteome d. a marker that is genetically inherited

B. a protein that is uniquely produced in a diseased state

Bt toxin is considered to be ________. a. a gene for modifying insect DNA b. an organic insecticide produced by bacteria c. useful for humans to fight against insects d. a recombinant protein

B. an organic insecticide produced by bacteria

Genetic recombination occurs by which process? a. independent assortment b. crossing over c. chromosome segregation d. sister chromatids

B. crossing over.

GMOs are created by ____. a. generating genomic DNA fragments with restriction endonucleases b. introducing recombinant DNA into an organism by any means c. overexpressing proteins in E. coli d. all of the above

B. introducing recombinant DNA into an organism by any means

Insulin produced by molecular cloning: a. is of pig origin b. is a recombinant protein c. is made by the human pancreas d. is recombinant DNA

B. is a recombinant protein

Linkage analysis ______. a. is used to create a physical map b. is based on the natural recombination process c. requires radiation hybrid mapping d. involves breaking and rejoining of DNA artificially

B. is based on the natural recombination process

The observation that the bacteria genus Chlamydia contains species that can only survive as intracellular parasites supports which viral origin hypothesis? a. Progressive b. Regressive c. Self-replicating d. Virus-first

B. regressive

Which statement is true? a. A virion contains DNA and RNA. b. Viruses are acellular. c. Viruses replicate outside of the cell. d. Most viruses are easily visualized with a light microscope

B. viruses are accellular

Which of the following is not associated with prions? a. Replicating shapes b. Mad cow disease c. DNA d. Toxic proteins

C. DNA

Which statement is true of reverse transcriptase? a. It is a nucleic acid. b. It infects cells. c. It transcribes RNA to make DNA. d. It is a lipid.

C. It transcribes RNA to make DNA.

Which of the following is NOT used to treat active viral disease? a. Vaccines b. Antiviral drugs c. Antibiotics d. Phage therapy

C. antibiotics

Oncogenic virus cores can be_______. a. RNA b. DNA c. neither RNA nor DNA d. either RNA or DNA

C. either RNA or DNA

Gene therapy can be used to introduce foreign DNA into cells ________. a. for molecular cloning b. by PCR c. of tissues to cure inheritable disease d. all of the above

C. of tissues to cure inheritable disease.

What is the most challenging issue facing genome sequencing? a. the inability to develop fast and accurate sequencing techniques b. the ethics of using information from genomes at the individual level c. the availability and stability of DNA d. all of the above

C. the ethics of using information from genomes at the individual level.

People with the CCR5Δ32 mutation of a T-cell surface protein can be exposed to some strains of HIV-1 without becoming sick. What step of the virus life cycle is likely to be inhibited with this mutation? a. Release b. Reverse transcription c. Uncoating d. Attachment

D. Attachment.

A patient presents at the clinic with an acute viral infection. Assays that analyze the viral life cycle classify the virus into Group V with a segmented genome. Which virus is the most likely diagnosis for the patient? a. Rabies virus b. Picornavirus c. HIV-1 d. Influenza A virus

D. Influenza A virus.

Which statement is NOT true of viral replication? a. A lysogenic cycle kills the host cell. b. There are six basic steps in the viral replication cycle. c. Viral replication does not affect host cell function. d. Newly released virions can infect adjacent cells.

D. Newly released virions can infect adjacent cells.

A protein signature is: a. the path followed by a protein after it is synthesized in the nucleus b. the path followed by a protein in the cytoplasm c. a protein expressed on the cell surface d. a unique set of proteins present in a diseased state

D. a unique set of proteins present in a diseased state

Genomics can be used in agriculture to: a. generate new hybrid strains b. improve disease resistance c. improve yield d. all of the above

D. all of the above. generate new hybrid strains improve disease resistance improve yield

ESTs are ________. a. generated after a cDNA library is made b. unique sequences in the genome c. useful for mapping using sequence information d. all of the above

D. all of the above. generated after a cDNA library is made. unique sequences in the genome. useful for mapping using sequence information.

The Flavr Savr Tomato: a. is a variety of vine-ripened tomato in the supermarket b. was created to have better flavor and shelflife c. does not undergo soft rot d. all of the above

D. all of the above. is a variety of vine-ripened tomato in the supermarket. was created to have a better flavor and shelf life. does not undergo soft rot.

Sequencing an individual person's genome a. is currently possible b. could lead to legal issues regarding discrimination and privacy c. could help make informed choices about medical treatment d. all of the above

D. all of the above. is currently possible. could lead to legal issues regarding discrimination and privacy. could help make informed choices about medical treatment.

Whole-genome sequencing can be used for advances in: a. the medical field b. agriculture c. biofuels d. all of the above

D. all of the above. the medical field. agriculture. biofuels.

A bacteriophage can infect ________. a. the lungs b. viruses c. prions d. bacteria

D. bacteria

Information obtained by microscopic analysis of stained chromosomes is used in: a. radiation hybrid mapping b. sequence mapping c. RFLP mapping d. cytogenetic mapping

D. cytogenetic mapping

Vaccines_______. A. are similar to viroids B. are only needed once C. kill viruses D. stimulate an immune response

D. stimulate an immune response

An apple grower notices that several of his apple trees with fungi growing on their trunks have developed necrotic ring spots, while other trees in the orchard that lack fungi appear healthy. What is the most likely conclusion the farmer can Make about the virus infecting his apple trees? a. The apple trees were infected by horizontal transmission. b. The fungi carry disease. c. The fungi attract disease-carrying insects. d. The apple trees were infected by vertical transmission.

D. the apple trees were infected by horizontal transmission.

Viruses_______. a. all have a round shape b. cannot have a long shape c. do not maintain any shape d. vary in shape

D. vary in shape

In any given species, there are at least how many types of aminoacyl tRNA synthetases? a. 20 b. 40 c. 100 d. 200

a. 20

The ara operon is an inducible operon that controls the production of the sugar arabinose. When arabinose is present in a bacterium it binds to the protein AraC, and the complex binds to the initiator site to promote transcription. In this scenario, AraC is a(n) ________. a. activator b. inducer c. repressor d. operator

a. activator

What processing step enhances the stability of pre-tRNAs and pre-rRNAs? a. methylation b. nucleotide modification c. cleavage d. splicing

a. methylation

Post-translational modifications of proteins can affect which of the following? a. protein function b. transcriptional regulation c. chromatin modification d. all of the above

a. protein function

Post-translational control refers to: a. regulation of gene expression after transcription b. regulation of gene expression after translation c. control of epigenetic activation d. period between transcription and translation

a. regulation of gene expression after translation

What are epigenetic modifications? a. the addition of reversible changes to histone proteins and DNA b. the removal of nucleosomes from the DNA c. the addition of more nucleosomes to the DNA d. mutation of the DNA sequence

a. the addition of reversible changes to histone proteins and DNA

A scientist introduces a mutation that makes the 60S ribosomal subunit nonfunctional in a human cell line. What would be the predicted effect on translation? a. Translation stalls after the initiation AUG codon is identified. b. The ribosome cannot catalyze the formation of peptide bonds between the tRNAs in the A and P sites. c. The ribosome cannot interact with mRNAs. d. tRNAs cannot exit the E site of the ribosome

a. translation stalls after the initiation AUG codon is identified.

Which feature of promoters can be found in both prokaryotes and eukaryotes? a. GC box b. TATA box c. octamer box d. -10 and -35 sequences

b. TATA box

How do enhancers and promoters differ? a. Enhancers bind transcription factors to silence gene expression, while promoters activate transcription. b. Enhancers increase the efficiency of gene expression, but are not essential for transcription. Promoter recognition is essential to transcription initiation. c. Promoters bind transcription factors to increase the efficiency of transcription. Enhancers bind RNA polymerases to initiate transcription. d. There is no difference. Both are transcription factor-binding sequences in DNA

b. enhancers increase the efficiency of gene expression, but are not essential for transcription. Promoter recognition is essential to transcription initiation.

What will result from the binding of a transcription factor to an enhancer region? a. decreased transcription of an adjacent gene b. increased transcription of a distant gene c. alteration of the translation of an adjacent gene d. initiation of the recruitment of RNA polymerase

b. increased transcription of a distant gene

If glucose is absent, but so is lactose, the lac operon will be _______. a. activated b. repressed c. activated, but only partially d. mutated

b. repressed.

A scientist mutates eIF-2 to eliminate its GTP hydrolysis capability. How would this mutated form of eIF-2 alter translation? a. Initiation factors would not be able to bind to mRNA. b. The large ribosomal subunit would not be able to interact with mRNA transcripts. c. tRNAi-Met would not scan mRNA transcripts for the start codon. d. eIF-2 would not be able to interact with the small ribosomal subunit.

b. the large ribosomal subunit would not be able to interact with mRNA transcripts for the start codon.

The -10 and -35 regions of prokaryotic promoters are called consensus sequences because _______ a. they are identical in all bacterial species b. they are similar in all bacterial species c. they exist in all organisms d. they have the same function in all organisms

b. they are similar in all bacterial species.

A scientist compares the promoter regions of two genes. Gene A's core promoter plus proximal promoter elements encompasses 70bp. Gene B's core promoter plus proximal promoter elements encompasses 250bp. Which of the scientist's hypotheses is most likely to be correct? a. More transcripts will be made from Gene B. b. Transcription of Gene A involves fewer transcription factors. c. Enhancers control Gene B's transcription. d. Transcription of Gene A is more controlled than transcription of Gene B.

b. transcription of Gene A involves fewer transcription factors.

The viral ________ play(s) a role in attaching a virion to the host cell. a. core b. capsid c. envelope d. both b and c

both B & C. capsid and envelope.

How many nucleotides are in 12 mRNA codons? a. 12 b. 24 c. 36 d. 48

c. 36

The binding of ________ is required for transcription to start. a. a protein b. DNA polymerase c. RNA polymerase d. a transcription factor

c. RNA polymerase

Alternative splicing has been estimated to occur in more than 95% of multi-exon genes. Which of the following is not an evolutionary advantage of alternative splicing? a. Alternative splicing increases diversity without increasing genome size. b. Different gene isoforms can be expressed in different tissues. c. Alternative splicing creates shorter mRNA transcripts. d. Different gene isoforms can be expressed during different stages of development.

c. alternative splicing creates shorter mRNA transcripts.

the RNA components of ribosomes are synthesized in the ________. a. cytoplasm b. nucleus c. nucleolus d. endoplasmic reticulum

c. nucleolus

Cancer causing genes are called ________. a. transformation genes b. tumor suppressor genes c. oncogenes d. mutated genes

c. oncogenes

Targeted therapies are used in patients with a set gene expression pattern. A targeted therapy that prevents the activation of the estrogen receptor in breast cancer would be beneficial to which type of patient? a. patients who express the EGFR receptor in normal cells b. patients with a mutation that inactivates the estrogen receptor c. patients with lots of the estrogen receptor expressed in their tumor d. patients that have no estrogen receptor expressed in their tumor

c. patients with lots of estrogen receptor expressed in their tumor.

Which event contradicts the central dogma of molecular biology? a. Poly-A polymerase enzymes process mRNA in the nucleus. b. Endonuclease enzymes splice out and repair damaged DNA. c. Scientists use reverse transcriptase enzymes to make DNA from RNA. d. Codons specifying amino acids are degenerate and universal.

c. scientists use reverse transcriptase enzymes to make DNA from RNA

Which pre-mRNA processing step is important for initiating translation a. poly-A tail b. RNA editing c. splicing d. 7-methylguanosine cap

d. 7-methlyguanosine cap

Which of the following are true of epigenetic changes? a. allow DNA to be transcribed b. move histones to open or close a chromosomal region c. are temporary d. all of the above

d. all of the above. allow DNA to be transcribed. move histones to open or close a chromosomal region. are temporary.

Which of the following are involved in posttranscriptional control? a. control of RNA splicing b. control of RNA shuttling c. control of RNA stability d. all of the above

d. all of the above. control of RNA splicing. control of RNA shuttling. control of RNA stability.

How does the regulation of gene expression support continued evolution of more complex organisms? a. Cells can become specialized within a multicellular organism. b. Organisms can conserve energy and resources. c. Cells grow larger to accommodate protein production. d. Both A and B

d. both A and B. cells can become specialized within a multicellular organism. organisms can conserve energy and resources.

The AUC and AUA codons in mRNA both specify isoleucine. What feature of the genetic code explains this? a. complementarity b. nonsense codons c. universality d. degeneracy

d. degeneracy

Binding of an RNA binding protein will ________ the stability of the RNA molecule. a. increase b. decrease c. neither increase nor decrease d. either increase or decrease

d. either increase or decrease.

Control of gene expression in eukaryotic cells occurs at which level(s)? a. only the transcriptional level b. epigenetic and transcriptional levels c. epigenetic, transcriptional, and translational levels d. epigenetic, transcriptional, posttranscriptional, translational, and post-translational levels

d. epigenetic, transcriptional, post-transcriptional, translational, and post-translational levels.

Which subunit of the E. coli polymerase confers specificity to transcription? a. α b. β c. β' d. σ

d. σ

What transcripts will be most affected by low levels of α-amanitin? a. 18S and 28S rRNAs b. pre-mRNAs c. 5S rRNAs and tRNAs d. other small nuclear RNAs

pre-mRNAs