Question 1

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

Accepted Answer

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 
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

Question 2

Who originally identified a highly condensed structure in the interphase of nuclei?

Accepted Answer

A) Lyon 
B) Barr 
C) Ohno 
D) None of the answers are correct 
A) Lyon 
B) Barr 
C) Ohno 
D) None of the answers are correct B

Question 3

The expression of a single allele is associated with which of the following?

Accepted Answer

A) X-inactivation 
B) Genomic imprinting 
C) Maternal inheritance 
D) Extra nuclear inheritance 
A) X-inactivation 
B) Genomic imprinting 
C) Maternal inheritance 
D) Extra nuclear inheritance B

Question 4

What are some diseases associated with imprinting?

Accepted Answer

A) Angelman Syndrome 
B) LHON 
C) Alzheimer's Disease 
D) All of the answers are correct 
A) Angelman Syndrome 
B) LHON 
C) Alzheimer's Disease 
D) All of the answers are correct

Question 5

The best term for the process by which some exons are included in a mature mRNA from one cell but are absent from the mRNA in another cell is

Accepted Answer

A)  RNA interference. 
B)  chromosomal remodeling. 
C)  alternative splicing. 
D)  Pre-mRNA splicing. 
A)  RNA interference. 
B)  chromosomal remodeling. 
C)  alternative splicing. 
D)  Pre-mRNA splicing.

Question 6

If a human cell has two Barr bodies then the genotype of the individual could be

Accepted Answer

A)  XXXY. 
B)  XXXXY. 
C)  XXY. 
D)  XYY. 
A)  XXXY. 
B)  XXXXY. 
C)  XXY. 
D)  XYY.

Question 7

What is the difference between the trithorax (TrxG) and polycomb (PcG) complexes of proteins?

Accepted Answer

A) TrxG proteins methylate lysine 27 on histone H3 while PcG complexes methylate lysine 4 on H3 
B) Methylation of lysine at position 4 on H3 results in silencing of gene expression 
C) 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. 
D) Methylation of H3 on lysine 27 can result in activation of transcription 
A) TrxG proteins methylate lysine 27 on histone H3 while PcG complexes methylate lysine 4 on H3 
B) Methylation of lysine at position 4 on H3 results in silencing of gene expression 
C) 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. 
D) Methylation of H3 on lysine 27 can result in activation of transcription

Question 8

Gene methylation can be detected through the use of restriction endonucleases. Usually these are used in pairs where one enzyme will digest only unmethylated DNA in its recognition sequence while the other is insensitive to methylation. Which of the following statements is correct?

Accepted Answer

A) The enzyme that is insensitive to methylation serves as a control to make sure the inability of the other enzyme to digest DNA is not due to a mutation. 
B) These are used in pairs since experiments have to be replicated and this one way of performing a replication of the experiment 
C) The experimental design is flawed since there should be a third enzyme that would serve as a positive cocntrol 
D)  This experimental design is able to detect most of the methylated C residues in a particular region of DNA. 
A) The enzyme that is insensitive to methylation serves as a control to make sure the inability of the other enzyme to digest DNA is not due to a mutation. 
B) These are used in pairs since experiments have to be replicated and this one way of performing a replication of the experiment 
C) The experimental design is flawed since there should be a third enzyme that would serve as a positive cocntrol 
D)  This experimental design is able to detect most of the methylated C residues in a particular region of DNA.

Question 9

Most imprinted genes are silenced. What is one exception to this rule?

Accepted Answer

A) H19 
B) Igf-2 
C) UBE3A 
D) SNRPN 
A) H19 
B) Igf-2 
C) UBE3A 
D) SNRPN

Question 10

In an in vitro translation assay radioactive amino acids can be incorporated into proteins and the proteins separated from the unincorporated amino acids. Given the following data what are the conclusions that you would come to?

Accepted Answer

A)  Double stranded RNA is more efficient at inhibiting translation than antisense RNA 
B)  Antisense RNA is more efficient at inhibiting translation than double stranded RNA 
C)  No conclusion about the efficiency of translation inhibiton can be made as the positive and negative controls did not perform appropriately 
D)  The experiment did not work since the antisense fibronectin did not have an effect on amino acid incorporation. 
A)  Double stranded RNA is more efficient at inhibiting translation than antisense RNA 
B)  Antisense RNA is more efficient at inhibiting translation than double stranded RNA 
C)  No conclusion about the efficiency of translation inhibiton can be made as the positive and negative controls did not perform appropriately 
D)  The experiment did not work since the antisense fibronectin did not have an effect on amino acid incorporation.

Question 11

A common way of studying methylation in cells is to sequence DNA samples before and after modification with sodium bisulfite. The sodium bisulfite deaminates Cytosine residues, generating Uracil residues, therefore resulting in a change in the sequence as compared to the non-modified DNA. Sodium bisulfite does not react with 5-methylcytosine so there will be no change in the sequence of those modified bases. When tumors are sequenced to study methylation patterns and epigenetic control, what would be the best control for sequencing using this technique?

Accepted Answer

A) Non-cancerous tissue DNA from a different individual but from the same organ 
B) Liver DNA from the same individual that the cancer sample is from 
C) DNA from non-cancerous tissue from the same individual's organ as the cancer 
D) A combination of DNA from liver, brain and muscle from the same individual that has the cancer 
A) Non-cancerous tissue DNA from a different individual but from the same organ 
B) Liver DNA from the same individual that the cancer sample is from 
C) DNA from non-cancerous tissue from the same individual's organ as the cancer 
D) A combination of DNA from liver, brain and muscle from the same individual that has the cancer

Question 12

It is frequently desirable to experimentally regulate gene regulation and then study the consequences of expressing or suppressing the specific gene. To accomplish this, different gene sequences are fused to promoters or sequences that will be expressed as mRNA. Which of the following would most likely result in regulatable expression?

Accepted Answer

A)  ARE 
B)  IRE 
C)  IBP 
D)  ICR 
A)  ARE 
B)  IRE 
C)  IBP 
D)  ICR

Question 13

What genes appear to be controlled by the Xic?

Accepted Answer

A) Xist and Tsix 
B) Xist 
C) TsiX 
D) Xic 
A) Xist and Tsix 
B) Xist 
C) TsiX 
D) Xic

Question 14

Northern blot analysis can be used to determine the relative amount and size of different RNA transcripts. Above is a representation of a northern blot analysis of several different tissues for the expression of a single gene. Which of the following statements is correct?

Accepted Answer

A)  Some of the samples contain incompletely processed mRNA 
B)  Some of the samples contain pre-mRNA 
C)  The mRNA is differentially spliced 
D)  All tissues express identical proteins 
A)  Some of the samples contain incompletely processed mRNA 
B)  Some of the samples contain pre-mRNA 
C)  The mRNA is differentially spliced 
D)  All tissues express identical proteins

Question 15

What gene(s) is/are encoded in the Xic?

Accepted Answer

A) Xce 
B) Xist 
C) Tsix 
D) Both the Tsix and Xist genes are in the Xic region 
A) Xce 
B) Xist 
C) Tsix 
D) Both the Tsix and Xist genes are in the Xic region

Question 16

Epigenetic inheritance may occur at which of the following stages?

Accepted Answer

A) Oogenesis 
B) Spermatogenesis 
C) Embryogenesis 
D) All of the answers are correct 
A) Oogenesis 
B) Spermatogenesis 
C) Embryogenesis 
D) All of the answers are correct

Question 17

A modification that occurs to a nuclear gene that alters gene expression, but not permanently, is called _______ inheritance.

Accepted Answer

A) extranuclear 
B) cytoplasmic 
C) maternal effect 
D) epigenetic 
E) nuclear 
A) extranuclear 
B) cytoplasmic 
C) maternal effect 
D) epigenetic 
E) nuclear

Question 18

Expression of ______ would inhibit X-inactivation.

Accepted Answer

A) Xic 
B) Xist 
C) Tsix 
D) All of the answers are correct 
E) None of the answers are correct 
A) Xic 
B) Xist 
C) Tsix 
D) All of the answers are correct 
E) None of the answers are correct

Question 19

What would be the consequence if an individual was homozygous for an IBP that could not bind iron but could bind to the IRE?

Accepted Answer

A)  Unregulated transferrin receptor levels 
B)  Increased degradation of ferritin 
C)  Possible iron toxicity to the cells at levels of iron that would not normally be toxic to a cell 
D)  There would be no predicted consequence to iron metabolism in the cell 
A)  Unregulated transferrin receptor levels 
B)  Increased degradation of ferritin 
C)  Possible iron toxicity to the cells at levels of iron that would not normally be toxic to a cell 
D)  There would be no predicted consequence to iron metabolism in the cell

Question 20

Both parents usually imprint the same gene.

Accepted Answer

A) True 
 B)False

Exam 16: Gene Regulation in Eukaryotes II: Epigenetics and Regulation at the RNA Level

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

Who originally identified a highly condensed structure in the interphase of nuclei?

The expression of a single allele is associated with which of the following?

What are some diseases associated with imprinting?

The best term for the process by which some exons are included in a mature mRNA from one cell but are absent from the mRNA in another cell is

If a human cell has two Barr bodies then the genotype of the individual could be

What is the difference between the trithorax (TrxG) and polycomb (PcG) complexes of proteins?

Gene methylation can be detected through the use of restriction endonucleases. Usually these are used in pairs where one enzyme will digest only unmethylated DNA in its recognition sequence while the other is insensitive to methylation. Which of the following statements is correct?

Most imprinted genes are silenced. What is one exception to this rule?

In an in vitro translation assay radioactive amino acids can be incorporated into proteins and the proteins separated from the unincorporated amino acids. Given the following data what are the conclusions that you would come to?

What genes appear to be controlled by the Xic?

Northern blot analysis can be used to determine the relative amount and size of different RNA transcripts. Above is a representation of a northern blot analysis of several different tissues for the expression of a single gene. Which of the following statements is correct?

What gene(s) is/are encoded in the Xic?

Epigenetic inheritance may occur at which of the following stages?

A modification that occurs to a nuclear gene that alters gene expression, but not permanently, is called _______ inheritance.

Expression of ______ would inhibit X-inactivation.

What would be the consequence if an individual was homozygous for an IBP that could not bind iron but could bind to the IRE?

Both parents usually imprint the same gene.

Overview of Genetics

Mendelian Inheritance

Chromosome Transmission During Cell Division and Sexual Reproduction

Extensions of Mendelian Inheritance

Non-Mendelian Inheritance

Genetic Linkage and Mapping in Eukaryotes

Genetic Transfer and Mapping in Bacteria and Bacteriophages

Variation in Chromosome Structure and Number

Molecular Structure of DNA and RNA

Chromosome Organization and Molecular Structure

DNA Replication

Gene Transcription and RNA Modification

Translation of MRNA

Gene Regulation in Bacteria

Gene Regulation in Eukaryotes I: Transcriptional Regulation

Genetics of Viruses

Gene Mutation and Dna Repair

Recombination and Transposition at the Molecular Level

DNA Technologies

Biotechnology

Genomics I: Analysis of DNA

Genomics II: Functional Genomics, Proteomics, and Bioinformatics

Medical Genetics and Cancer

Developmental Genetics

Population Genetics

Quantitative Genetics

Evolutionary Genetics

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