BIO 151 Transcription

If a particular DNA sequence has a cytosine content of 20%, what is its adenine content? A. 10% B. 20% C. 30% D. 40% E. Cannot be determined

C. 30%

If the sequence of a piece of DNA is 3'TACGTTAA - 5' which of the following is the sequence of the complementary piece of DNA? A. 5'- AUGCAAUU- 3' B. 3'-AUGCAAUU-5' C. 5'-ATGCAATT-3' D. 3'-ATGCAATT- 5'

C. 5'-ATGCAATT-3'

If the sequence of an RNA transcript is 3'- CAGCUUAAGCUAGCUAUGA - 5' Then which of the following must be the sequence of the DNA template used by RNA polymerase to produce this RNA? A. 5'-GUCGAAUUCGAUCGAUACU-3' B. 3'- GUCGAAUUCGAUCGAUACU - 5' C. 5'- GTCGAATTCGATCGATACT - 3' D. 3'- CAGCTTAAGCTAGCTATGA - 5'

C. 5'-GTCGAATTCGATCGATACT- 3'

RNA GCAGCC DNA 5'-GCGCGTCGGTACA-3' Above is a DNA template and a partial mRNA transcript. What will the next RNA base be? A.A B.G C.C D.T E. U

C. C

Which of the statements below is FALSE? A. The promoter and termination sequences are not made into mRNA. B. RNA polymerase adds nucleotides to the RNA transcript. C. Transcription initiation occurs when RNA polymerase and transcription factors recognize a promoter sequence along the coding strand of DNA. D. Transcription occurs in the 3'-5' direction along the DNA template forming an mRNA in the 5'-3'direction with nucleotides added to the 3' end.

C. Transcription initiation occurs when RNA polymerase and transcription factors recognize a promoter sequence along the coding strand of DNA.

Ribose differs from deoxyribose in that ribose: A. has an extra phosphate group B. had one less hydroxyl group the deoxyribose C. has one more hydroxyl group than deoxyribose D. is missing a phosphate group

C. has one more hydroxyl group than deoxyribose

During RNA processing A.All of the exons are removed and discarded B.The RNA molecule is made from a DNA template. C.Introns are cut from the RNA and the exons are spliced together. D.The RNA molecule is translated into a protein molecule.

C.Introns are cut from the RNA and the exons are spliced together.

True or False. Both DNA and RNA have a 5-carbon sugar in their backbones.

True

True or false. Whichever DNA strand is transcribed, the RNA polymerase reads the template strand from 3' to 5'.

True

A molecule of pre-mRNA has four exons and three introns. Which of the following are possible combinations of the exons? Assume that the order they are written is the order that they will be in the mRNA. 1. Exon 1, Exon 2, Exon 3, Exon 4 2. Intron 1, Exon 1, Intron 2, Exon 2, Intron 3, Exon 3, Intron 4, Exon 4 3. Exon 1, Exon 3, Exon 4 4. Exon 4, Exon 1, Exon 2, Exon 3

1. possible 2. not possible 3. possible 4. not possible

In the following DNA sequence, the top strand is the template strand. 5'-GTAGCCGATAAT-3' 3'-CATCGGCTATTA-5' If the first base pair G-C (in bold) is changed to T-A, what would the resulting nucleotide be in the mRNA? A. A B. C C. T D. G

A. A

If you made a change in the promoter sequence in the DNA that inactivated the promoter, then what would happen at the RNA level? A. RNA polymerase would not be able to bind to the DNA, so no RNA would be made. B. The mutation of the DNA would be carried through to the RNA sequence. C. Nothing, the RNA would be made as usual. D. The DNA helicase would not be able to recognize and bind the DNA, so the RNA would not be made

A. RNA polymerase would not be able to bind to the DNA, so no RNA would be made.

Why do DNA and RNA have overall negative charges? A.The phosphate group that makes up every nucleotide is negatively charged. B. The ribose group the makes up every nucleotide is negatively charged. C. The A, T and U nucleotides are negatively charged because they only form 2 hydrogen bonds. D.Because the molecules have polarity and can be either 3'-5' or 5'-3'.

A.The phosphate group that makes up every nucleotide is negatively charged.

Which of the following statements are true? I. RNA has an OH on its 2` carbon and DNA has an H on its 2' carbon. II. DNA prefers to be double-stranded, RNA prefers to be single-stranded. III. DNA and RNA have the same nitrogenous bases. IV. DNA has a 5-carbon sugar in its backbone, RNA has a 6-carbon sugar. V. Phosphodiester covalent bonds link nucleotides together along the DNA backbone. VI. Covalent bonds link together complementary DNA strands. A. II, IV, V B. I, II, V C. I, II, V, VI D. II, III, VI E. III, IV, VI

B. I, II, V

Where in a eukaryotic cell, where are transcription factors active (doing their job)? A.In ribosomes B.In the nucleus C.In the cytosol / cytoplasm D.In the rough endoplasmic reticulum.

B. In the nucleus

Is the promoter transcribed during transcription? A. Yes B. No

B. No

YFG is a gene in prokaryotes. If the order of nucleotides in the promoter region was flipped so they faced the opposite direction, (but nothing was changed in the gene itself), then how would that affect transcription of the YFG gene? A. The gene would be transcribed backwards (3' becomes 5'). B. Sigma would bind and RNA polymerase would transcribe away from the YFG gene (in the opposite direction) on the coding strand. C. It would not affect transcription. D. Sigma would bind and RNA polymerase would transcribe the YFG gene on the coding strand.

B. Sigma would bind and RNA polymerase would transcribe away from the YFG gene (in the opposite direction) on the coding strand.

Occasionally, a double-stranded DNA molecule contains a uracil base (U) instead of a (T). If a U were present in the template strand of DNA, what base would be incorporated into the RNA transcript at that position? A. U B. C C. T D. A E. G

D. A

In most cases, introns are spliced out of mature messenger RNA (mRNA) and are not a part of the final translated protein product of a gene. Even though they are not included in the final protein, why are introns important? A. Introns can generate non coding RNAs that influence gene expression B. Introns allow for alternative splicing of exons to create multiple proteins from one gene sequence C. Introns are involved in some special regulatory functions like mRNA export and non-sense mediated decay. D. All of the above.

D. All of the above.

If a particular mRNA sequence has a cytosine content of 25%, what is its adenine content? A. 12.5% B. 25% C. 50% D. Cannot be determined

D. Cannot be determined

In eukaryotes, where do general transcription initiation factors bind? A. 5' UTR B. Enhancer C. Terminator D. Promoter E. RNA polymerase

D. Promoter

Which of the following statements are true? I. All RNA is translated to generate proteins. II. All introns have identical lengths and sequences. III. An exon is considered a "coding sequence" of DNA, and its information is retained in the processed mRNA within a cell. IV. The poly-A tail contributes to mRNA stability. A. III only B. II, III C. I, III, IV D. I-IV E. III, IV

E. III, IV

True or false. Muscle cells make different proteins than nerve cells because the two cell types contain different sequences of DNA.

False

5'-TGAC-3' is a sequence of nucleotides on a single strand of DNA. In this strand, the phosphodiester bond between the guanine and the adenine connects: a. the 3' end of the guanine to the 5' end of the adenine. b. the 2' end of the adenine to the 3' end of the guanine. c. the 5' end of the guanine to the 1' end of the adenine. d. the 5' end of the guanine to the 2' end of the adenine. e. the 3' end of the adenine to the 5' end of the guanine.

a. the 3' end of the guanine to the 5' end of the adenine.

Sometimes the DNA sequence gets mutated and an adenine is paired to a cytosine. Why is this interaction unstable? a. the chemical groups that form hydrogen bonds are in the wrong positions b. the phosphate groups of the two bases repel each other c. an ionic bond cannot be formed between the two d. the charges on the bases repel one another

a. the chemical groups that form hydrogen bonds are in the wrong positions

Imagine you have discovered a new species of bacteria. To begin your investigation of this organism, you run an assay on the total nucleotide content of the bacterial DNA. If the cytosine content of DNA from the bacterial cells is 40%, what is the adenine content? a.10% b.40% c.20% d.It is not possible to calculate this. e.5%

a.10%

5' GCGCGTCGGTACA 3' is a DNA template. GCAGCC is the RNA sequence that has been transcribed (notice that the 5' and 3' ends of the RNA have not been indicated). Which base will be added next to the growing RNA molecule? a.Cytosine b.Uracil c.Adenine d.Guanine e.Thymine

a.Cytosine

A template DNA strand contains the sequence 5'-ATGCTGAC-3'. The corresponding RNA transcript is: a. 5'-GTCAGCAT-3'. b. 5'-GUCAGCAU -3'. c. 5'-TACGACTG-3'. d. 5'-UACGACUG-3'.

b. 5'-GUCAGCAU -3'.

Why does the promoter region of DNA consist of mostly adenines and thymines? a. RNA polymerases are better at incorporating uracils and thymines into RNA molecules than incorporating guanines and cytosines. b. This is the region for separating DNA strands, and A-T base pairs are easier to separate than G-C base pairs. c. Accessory proteins like sigma factors or transcription factors bind more easily to AT-rich sequences than they do to GC-rich sequences. d. It is possible to create more unique sequences for recognition with adenines and thymines than it is with guanines and cytosines.

b. This is the region for separating DNA strands, and A-T base pairs are easier to separate than G-C base pairs.

Which of the following describes where a poly-A sequence is added to the RNA transcript? a. It is added 3'-end of a transcript. This occurs in the cytoplasm b. It is added 5' end of a transcript. This occurs in the cytoplasm. c. It is added 3'-end of a transcript. This occurs in the nucleus. d. It is added to the 5' end of a transcript. This occurs in the nucleus.

c. It is added 3'-end of a transcript. This occurs in the nucleus.

Where does the energy come from to add a uracil to the 3' end of a transcript? a. From the formation of hydrogen bonds between the DNA and RNA. b. The energy released by allowing the uracil to complementary base pair with an adjacent thymine. c. The hydrolysis of two phosphate groups from the incoming UTP molecule. d. The cell's supply of ATP. e. The hydrolysis of one phosphate group from the incoming UTP molecule

c. The hydrolysis of two phosphate groups from the incoming UTP molecule.

What is the name of the enzyme complex that forms at the start of transcription? a.DNA gyrase b.DNA polymerase c.RNA polymerase d.RNA helicase

c.RNA polymerase

An RNA transcript is synthesized in which direction? a. 5' to 5' b. N terminus to C terminus c. C terminus to N terminus d. 5' to 3' e. 3' to 5'

d. 5' to 3'

True or False. Phosphodiester covalent bonds link RNA nucleotides together.

true