Genetics Exam 5

Which of the following is an example of a palindromic DNA sequence?

5' -CTGCAG - 3' 3' -GACGRC - 5'

Which environmental agent shown can induce mutations?

All of the answers are correct

What is the make up of the bacterial and eukaryotic SRP, respectively?

Bacterial: 1 ncRNA, 1 protein; Eukaryotic: 1 ncRNA, 6 proteins

What genes are encoded in the Xic?

Both of Tsix and Xist are genes are in the Xic region

Abnormal levels of miRNAs are associated with nearly all forms of what type of human disease?

Cancer

Ribozymes are RNA molecules with what type of activity?

Catalytic

Into which gene of the CRISPR-Cas system are fragments of bacteriophage DNA inserted?

Crispr

CpG islands are associated with which of the following?

DNA methylation

Genomic imprinting is a result of

DNA methylation

Which technique uses dideoxynucleotides?

DNA sequencing

What human disease is associated with mutations in Drosha?

Familial amyotrophic lateral sclerosis

What is a major difference between the general and regulatory transcription factors?

General transcription factors are essential for any transcription for all genes while regulatory transcription factors regulate transcription of specific genes

The ncRNA HOTAIR recruits what type of proteins to target genes?

Histone-modifying complexes

The CRISPR-Cas system in bacteria is most similar to what system in vertebrates?

Immune System

With which injection did Mello and Fire observe the lowest amount of mex-3 probe staining?

Injected with double-stranded RNA

A cDNA library differs from a genomic library in which way?

It contains only coding sequences, not introns

What procedure is used to identify a specific RNA within a mixture of many RNA molecules?

Northern Blotting

You work in a lab that is studying PIWI proteins. You have isolated piRISCs and piRITSs from a cell. What would be one way to identify which complexes are piRISCs and which are piRITSs?

One of the proteins in the piRITSs should have a nuclear localization signal.

In order of their occurance what are the steps in RNA interference?

Processing of RNA transcript by DGCR8, transport to cytoplasm, processing by Dicer, binding to RISC, binding to target mRNA

Select the ncRNA that facilitates the binding of telomerase to the telomere and acts as a template for DNA replication.

TERC

What general transcription factor is most often affected by regulatory transcription factors?

TFIID

What occurs during the annealing stage of a PCR reaction?

The primers bind to the template DNA.

One definition of epigenetics would be

The study of reversible mechanisms that lead to changes in gene expression that do not involve changes in DNA sequence.

What effect will a mutation in IRP that prevents it from binding to iron have on an individual?

There will be excess transferrin, so iron intake must be lowered.

Which of the following is not an example of a cause of a spontaneous mutation?

UV light

What genes appear to be controlled by the Xic?

Xist and Tsix

A temporary change in the structure of a nitrogenous base is called _________

a tautomeric shift

What are some of the steps in eukaryotic transcriptional control?

a transcriptional activator recruits nucleosome remodeling proteins that alter nucleosome positioning, modification, and composition. This allows for the formation of an open chromatin complex, and binding of general transcription factors and RNA polymerase II. Finally, as transcription elongation occurs, histone cores are evicted from the DNA to allow the RNA polymerase to transcribe the gene.

What are some types of the molecular changes that underlie epigenetic gene a. DNA methylation and chromatin remodeling b. depurination and chromatin remodeling. c. depurination of cytosine and thymidine residues d. DNA methylation and depurination of cytosine residues

a. DNA methylation and chromatin remodeling

You are performing a mobility shift assay with a protein complex that is composed of proteins A, B, C, & D, each of which can bind to the DNA of interest. You run the gel with the lanes as follows: Lane 1: Protein A + DNA Lane 2: Proteins A + B + DNA Lane 3: Proteins A + B + C + DNA Lane 4: Proteins A + B + C + D + DNA In which lane will the DNA run closest to the top of the gel? a. Lane 4 b. Lane 1 c. Lane 3 d. Lane 2

a. Lane 4

Consider the two key roles that have been identified for SRP RNA. You have isolated a mutant SRP RNA. This RNA is able to perform its role as a scaffold for SRP proteins, but has lost its other function. How will this affect translation of SRP-containing proteins? a. Partially translated proteins will be stuck in the cytosol. b. Translation will proceed normally. c. Partially translated proteins will be stuck in the ER lumen. d. Partially translated proteins will be stuck in the nucleus.

a. Partially translated proteins will be stuck in the cytosol.

Anticipation is associated with which of the following? a. TRNE mutations b. intergenic suppressors c. nonsense mutations d. up-promoter mutations

a. TRNE mutations

Imagine all the histone H3 molecules in the cell have a mutation that changes their lysine-9 residue to an alanine. Assuming this cell could still live, what would be the result? a. The ability of the cell to form heterochromatin would be hindered. b. The ability of the cell to form euchromatin would be hindered. c. There would little effect because lysine and alanine are similar amino acids. d. The ability of the cell to imprint genes would be hindered.

a. The ability of the cell to form heterochromatin would be hindered.

What is the difference between the trithorax (TrxG) and polycomb (PcG) complexes of proteins? a. TrxG complex proteins activate gene expression by methylating lysine 4 on H3, while PcG complex proteins repress gene expression by methylating lysine 27 on H3. b. Methylation of lysine at position 4 on H3 results in silencing of gene expression c. TrxG proteins methylate lysine 27 on histone H3 while PcG complexes methylate lysine 4 on H3 d. Methylation of H3 on lysine 27 can result in activation of transcription

a. TrxG complex proteins activate gene expression by methylating lysine 4 on H3, while PcG complex proteins repress gene expression by methylating lysine 27 on H3.

Antibodies can be used as probes for which of the following techniques? Multiple Choice a. Western blotting b. Southern blotting c. Eastern blotting d. Northern blotting

a. Western blotting

Which DNA repair process utilizes MutL, MutH, and MutS proteins in E. coli? a. mismatch repair b. homologous recombination repair c. nucleotide excision repair d. base excision repair e. nonhomologous end joining (NHEJ) f. direct repair

a. mismatch repair

SmY RNAs are a family of ncRNAs in nematodes that are thought to be involved in a special type of RNA splicing. Based on this function, SmY RNAs are most likely members of which category of ncRNAs? Multiple Choices a. nRNA b. tRNA c. siRNA d. snoRNA

a. nRNA

The results of the replica plating experiments by the Lederbergs supported which of the following theories? a. random mutation theory b. physiological adaptation theory c. both theories d. neither theory

a. random mutation theory

Consider the following DNA sequence, which codes the first portion of a long protein beginning at the ATG (AUG in mRNA) start codon. 5' ATG CCC CGC AGT AGG GGG TGG AGA 3' Which of the mutated sequences listed is most likely to be a deleterious mutation? a. 5' ATG CCG CGC AGT AGG GGG TGG AGA3' b. 5' ATG CCC CGC AGT AGG GGG TGA AGA3' c. 5' ATG CCC CGC AGT AGG GAG TGG AGA3'

b. 5' ATG CCC CGC AGT AGG GGG TGA AGA3'

Based on what you know about cartilage-hair hypoplasia, which strategy involving ncRNAs do you anticipate would be useful in treating this disease? Multiple Choice a. Targeting of the ncRNA-processing machinery b. A viral vector to restore a particular ncRNA c. Anti-ncRNA oligonucleotides d. Use of DNA demethylating agents and histone deacetylase inhibitors

b. A viral vector to restore a particular ncRNA

Which types of mutations are least likely to be subjected to natural selection? a. Nonsense b. Silent c. Missense d. Insertion

b. Silent

A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to histones. What effect would you expect this mutation has on the expression of this gene? a. The effect on gene expression is impossible to predict. b. The expression of the gene would be abnormally low or absent. c. The gene would encode a different protein instead. d. The promoter of the gene will be constantly available to transcription factors and RNA polymerase. e. The expression of the gene would be abnormally high.

b. The expression of the gene would be abnormally low or absent.

The Avy allele of the Agouti gene involves the insertion of a transposable element upstream from the normal Agouti promoter. The transposable element carries a promoter that causes the overexpression of the Agouti gene. Mice carrying this allele tend to have coat colors that are more yellow than mice that don't have this transposable element. If pregnant female mice are fed a diet that contains chemicals that increase DNA methylation, how would you expect that this diet would affect the coat color of offspring carrying the Avy allele? a. Their fur would be more yellow because the Agouti gene would tend to be over expressed. b. Their fur would be less yellow (darker brown) because the Agouti gene would tend to be under expressed. c. Their fur would be less yellow (darker brown) because the Agouti gene would tend to be over expressed. d. Their fur would be more yellow because the Agouti gene would tend to be under expressed.

b. Their fur would be less yellow (darker brown) because the Agouti gene would tend to be under expressed.

What effect will a mutation in IRP that prevents it from binding to iron have on an individual? a. There will be excess ferritin, so iron intake must be lowered. b. There will be excess transferrin, so iron intake must be lowered. c. Transferrin will not be made, so iron intake must be maximized. d. Ferritin will not be made, so iron intake must be maximized.

b. There will be excess transferrin, so iron intake must be lowered.

You are working in a lab that studies ncRNAs. You develop an assay to isolate ncRNAs and any associated molecules. You must then identify the molecules you have isolated. You find a molecule that is associated with an ncRNA that is not changed by protease, RNase, or DNase. The associated molecule is most likely a. DNA. b. a small molecule. c. an mRNA. d. a protein.

b. a small molecule.

A temporary change in the structure of a nitrogenous base is called ______. a. depurination b. a tautomeric shift c. deamination d. None of the answers are correct.

b. a tautomeric shift

The use of fluorescently-labeled dideoxynucleotides is a characteristic of what type of sequencing? a. base-specific DNA cleavage b. automated DNA sequencing

b. automated DNA sequencing

piRNA sequences are complimentary to a. another RNA within the piRISC. b. mRNA from a transposable element. c. bacteriophage DNA. d. the Crispr gene.

b. mRNA from a transposable element.

Hematopoietic stem cells are _____. a. pluripotent b. multipotent c. totipotent d. unipotent

b. multipotent

What do competent cells do? a. rejoin DNA strands without the aid of DNA ligase b. take up DNA from the external environment c. resist transfection by a viral vector d. utilize transposons as a vector

b. take up DNA from the external environment

What is the purpose of RT(reverse transcriptase)-PCR? a. to follow the amount of a specific PCR product in real-time b. to quantify RNA in a cell c. to nonspecifically amplify DNA d. to conduct a PCR reaction without the use of primers

b. to quantify RNA in a cell

If a point mutation increases the number of offspring an organism can produce, it would be called a _____ mutation.

beneficial

Which DNA sequence would also work in place of the following bi-directional enhancer?5' GTTC 3' 3' CAAG 5' a. 5' CAAG 3' 3' GTTC 5' b. 5' CTTG 3' 3' GAAC 5' c. 5' GAAC 3' 3' CTTG 5' d. 5' CTTC 3' 3' GAAG 5'

c. 5' GAAC 3' 3' CTTG 5'

Prior to the discovery of Taq polymerase, PCR could be carried out in a more laborious manner by adding a non-thermostable polymerase to each round of the reaction. In order for this reaction to work, when should the non-thermostable polymerase be added? a. After primer extension b. Before denaturation c. After primer annealing

c. After primer annealing

CpG islands are associated with which of the following? a. steroid hormone activity b. termination of translation c. DNA methylation d. nucleosome location

c. DNA methylation

In an in vitro translation assay radioactive amino acids can be incorporated into proteins and the proteins separated from the unincorporated amino acids (higher counts per minute indicates more protein synthesis). Given the following data what are the conclusions that you would come to? a. The experiment did not work since the antisense fibronectin did not have an effect on amino acid incorporation. b. Antisense RNA is more efficient at inhibiting translation than double-stranded RNA c. Double-stranded RNA is more efficient at inhibiting translation than antisense RNA d. No conclusion about the efficiency of translation inhibition can be made as the positive and negative controls did not perform appropriately

c. Double-stranded RNA is more efficient at inhibiting translation than antisense RNA

The ncRNA HOTAIR recruits what type of proteins to target genes? Multiple Choice a. RNA polymerase b. Transcription factors c. Histone-modifying complexes d. Histone acetyltransferase

c. Histone-modifying complexes

The CRISPR-Cas system in bacteria is most similar to what system in vertebrates? Multiple Choice a. Nervous system b. Circulatory system c. Immune system d. Digestive system

c. Immune system

In order of their occurrence what are the steps in RNA interference? Multiple Choice a. Processing of RNA transcript by DGCR8, binding to RISC, transport to cytoplasm, processing by Dicer, binding to target mRNA b. Processing by Dicer, processing of RNA transcript by DGCR8, transport to cytoplasm, binding to RISC, binding to target mRNA c. Processing of RNA transcript by DGCR8, transport to cytoplasm, processing by Dicer, binding to RISC, binding to target mRNA d. Processing of RNA transcript by DGCR8, processing by Dicer, transport to cytoplasm, binding to RISC, binding to target mRNA

c. Processing of RNA transcript by DGCR8, transport to cytoplasm, processing by Dicer, binding to RISC, binding to target mRNA

Expression of ______ would inhibit X-chromosome inactivation. a. Xic b. Xist c. Tsix d. All of the answers are correct. e. None of the answers are correct.

c. Tsix

Which DNA repair process identifies daughter strands by methylation? a. direct repair b. nonhomologous end joining (NHEJ) c. mismatch repair d. homologous recombination repair e. base excision repair f. nucleotide excision repair

c. mismatch repair

Regulatory transcription factors may influence gene expression in which of the following ways? a. directly recruiting RNA polymerase to the promoter without interacting with any other proteins b. influencing the ability of the RNA polymerase to perform elongation c. recruiting proteins to the promoter that enhance chromatin compaction d. by directly interacting with TFIII to inhibit its binding to the core promoter

c. recruiting proteins to the promoter that enhance chromatin compaction

Site-directed mutagenesis allows researchers to produce a mutation at a ______ within a cloned DNA segment. a. semilocalized site that can later be identified by sequencing b. random site c. specific site

c. specific site

Chromatin remodeling complexes alter nucleosomes, this occurs when

complexes of ATP-dependent proteins may reposition, evict, or change nucleosome composition

Which of the following is an example of a base analog? a. nitrous acid b. EMS c. nitrogen mustards d. 5BU e. acridine dyes

d. 5BU

Which environmental agent shown can induce mutations? a. UV radiation b. x-rays c. gamma rays d. All of the answers are correct.

d. All of the answers are correct.

What is an example of a suppressor mutation? a. an intragenic mutation that restores protein structure b. an intergenic mutation that increases the activity of a protein performing the same function as the mutated protein c. an intergenic mutation that alters a transcription factor to activate the expression of a compensating protein d. All of the answers are possible suppressor mutations.

d. All of the answers are possible suppressor mutations.

What human disease is associated with mutations in Drosha? Multiple Choice a. Alzheimer disease b. Heart arrhythmias c. Lung cancer d. Familial amyotrophic lateral sclerosis

d. Familial amyotrophic lateral sclerosis

cDNA is made using what as the starting material? a. viral DNA b. chromosomal DNA c. plasmid vectors d. RNA

d. RNA

Which of the following is an example of a pluripotent cell? a. nerve cells b. fetal heart cells c. red blood cells d. embryonic stem cells e. umbilical cord blood

d. embryonic stem cells

The conversion of cytosine to uracil in DNA is an example of _____.

deamination

Which of the following is an example of epigenetic inheritance?

expression of the Igf2 gene based on methylation of the ICR and DMR regions

Acetylation of histones results in

formation of an open chromatin structure

A collection of recombinant vectors that carry fragments of chromosomal DNA is called a

genomic library

The origins of which of the following cell types creates the least amount of ethical debate?

hematopoietic stem cells

piRNA sequences are complimentary to

mRNA from transposable element

What is the molecular mechanism for imprinting a gene?

methylation

What process repairs damage from UV radiation?

nucleotide excision repair

Small circular pieces of bacterial DNA that are used as vectors in cloning experiments are called

plasmids

Translocations and inversions may cause which of the following

position effect

A translocation that moves a gene from an area of euchromatin to heterochromatin would typically cause _________ in the expression of the gene.

reduction

An RNA molecule with catalytic activity is called a

ribozyme

What types of mutations are least likely to be subjected to natural selection?

silent

SmY RNAs are a family of ncRNAs in nematodes that are thought to be involved in a special type of RNA splicing. Based on this function, SmY RNAs are most likely members of which category of ncRNAs?

snRNA

What do competent cells do?

take up DNA from the external environment

A queen bee is larger than the female worker bees in a hive. The queen develops functional ovaries that allow her to produce up to 2000 eggs a day. What determines which bees become queen bees?

the larvae raised on a diet of royal jelly

DNA ligase is needed in a cloning experiment for what reason?

to covalently link the sugar-phosphate backbones of the two DNA fragments

Which of the following terms describes a cell that can form any other cell of the organisms?

totipotent

In the following sequence of DNA, the italicized base has been mutated. What type of mutation is this?

transversion

The function of reverse transcriptase is to

use RNA as a template to make DNA