Biochemistry 2280A Lecture Notes - Lecture 22: Gene Expression, Rna Editing, Polyadenylation

1) A valuable tool for assessing the transcriptome (i.e., thegenes actively expressed in cells or tissues in response tospecific signals or environmental changes) is
a) DNA microarrays or DNA chips.
B) SNP analysis.
C) protein arrays.
D) All of the choices listed are correct.

2) Why is the eukaryotic proteome so much larger than the numberof genes found in an organism?

A) Proteins are large molecules.

B) Differential intron splicing can produce more than one proteinproduct from a gene, and proteins are further posttranslationallymodified.

C) Many proteins are made from mitochondrial DNA, and this is nottaken into account.

D) The statement is incorrect: the proteome is equal to the numberof genes.

3)The number of mRNA transcripts in a cell fluctuate over timeas the pattern of gene expression changes. These transcripts arecollectively referred to as

A)regulatory transcripts. B)the transcriptome. C)theexpresstome. D)the proteome.

QuestionGroup: #21 Gene expression 2

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21

The direct end result of gene expression is which of the following?

A

Amino acids

B

Translation

C

Proteins

D

Carbohydrates

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QuestionGroup: #22 Mutation

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22

Which of the following is the ways in which nucleotide mutations lead to altered proteins?

A

One nucleotide is substituted by another nucleotide, which can cause an early stop codon to be incorporated into the amino acid sequence resulting in a truncated protein.

B

One nucleotide is replaced by another nucleotide, which can change an amino acid in the protein sequence

C

Nucleotides are inserted into a nucleotide sequence causing a frameshift in the sequence.

D

All three choices may cause mutations.

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QuestionGroup: #23 Mutation 2

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23

Mutations are the result of which of the following?

A

Change in the normal nucleotide sequence in the DNA directly resulting in different carbohydrates

B

Change in the normal nucleotide sequence in the DNA directly resulting in different proteins

C

Change in the order of transfer RNA to messenger RNA so that the transfer RNA take over the role of Messenger RNA

D

Primarily an alteration in the sequence of nucleotides in the abnormal proteins

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QuestionGroup: #24 Cell division

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24

There are two major kinds of cell division. Which of the following plays a major role in promoting genetic diversity?

A

Meiosis since it causes the cells to make more daughter cells than mitosis

B

Mitosis since it causes the cells to duplicate and eventually have mutations

C

Meiosis since it causes the DNA sequences to be separated into new patterns in the daughter cells.

D

Mitosis since it essential for the ovaries in humans to separate and duplicate

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QuestionGroup: #25 Cancer

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25

Genes that slow down or stop the cell cycle are called...

A

Apoptotic genes

B

Oncogenes

C

Restriction genes

D

Tumor suppressor genes

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QuestionGroup: #26 Cancer2

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26

The common theme in the development of all cancers is...

A

Mutation

B

Evolution

C

Infection

D

Syncopation

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QuestionGroup: #27 Genetics

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27

Punnett's square is which of the following?

A

Example of all possible combinations of alleles

B

Example of all possible combinations of chromosomes

C

Example of only certain combination of alleles since some will not be expressed.

D

Example of all possible combinations of DNA

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QuestionGroup: #28 Embryo development

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28

Which of the following is the end of the cleavage phase?

A

A fetus

B

Formation of a blastocyst

C

Implantation to the lining of the uterus

D

Fewer number of cells

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QuestionGroup: #29 Development of organ system

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29

For organs to be differentiated, which of the following is the first step?

A

Stem cells trigger the development of differentiated cells

B

Tissues assemble into organ systems such as blood

C

Tissue specific genes in stem cells are triggered

D

Differentiated cells form tissues

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QuestionGroup: #30 Development and society

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30

A pregnant mother ingests a chemical which her mother said would be great for the baby. When the baby was born, it had a large head and flippers for arms. What caused this phenotype?

A

The chemicals were teratogens which influenced oxidative phosphorylation causing the changes in the phenotype.

B

The chemicals influenced the expression of different stem cells.

C

There is no way to assume the chemicals caused the phenotype since we have no data on other mothers who took this medicine. It could have been purely by chance.

D

The chemicals were teratogens which caused the baby to show early signs of evolution.

22. What is probably the single most important distinction between bacteria and eukaryotes?

a. transcription

b. the separation of the cell's genetic material from the surrounding cytoplasm

c. the existence of ribosomes

d. RNA processing in bacteria

e. antibiotics

23. Which one does NOT characterize an open reading frame (ORF)

a. Uses six reading frames during translation

b. Contains a start codon

c. Contains a stop codon

d. Its length is in multiples of 3 nucleotides

e. It should have the number of codons for a protein or on average ~250 codons in length.

24. Nested intronic genes lie within the non-coding intronic region of a larger gene, and occur in the human genome.

a. True

b. False

25. How would you characterize this statement: EF-Tu will hydrolyze GTP only if the codon:anticodon & tRNA:amino acid matchings are correct

a. Transcription; initiation steps

b. Transcription; termination steps

c. Translation: initiation steps

d. Tanslation: elongation steps

e. Spliceosome

26. Regarding the transcription unit architecture of the Escherichia coli genome, which one is FALSE?

a. Each of the 4,661 transcription units comprised an average of 1.1 modular units.

b. 3,010 transcription units (~65%) are monocistronic.

c. 1,652 transcription units (35%) contain more than one ORF (polycistronic)

d. The largest transcription unit is equivalent to 16 ORFs with numerous introns.

e. 398 transcription units (~9%) are nested within each other in opposite transcriptional orientation

27. Regarding RNA interference (RNAi), which one is FALSE?

a. It is a common and conserved mechanism in eukaryotic cells.

b. Originally discovered in bacteria and plant viruses.

c. A form of primitive immunity to protect the genome.

d. Pre microRNA (miRNA) genes have been found in introns.

e. Recent research shows that exogenous plant miRNAs in food can regulate the expression of target genes in mammals.

28. Aminoacyl-tRNA synthetases

a. Recognize the 3’UTR

b. The genes for these enzymes fall into the family of inducible genes

c. The enzymes are imported into the nucleus

d. Covalently attaches an amino acid to the appropriate tRNA. This takes place in the cytoplasm.

e. Forms the peptide bond during protein synthesis

29. What is the process by which complementary RNAs are made from a DNA template?

a. translation

b. transcription

c. protein synthesis

d. transduction

e. transliteration