Ch.15 Genes & Proteins

Rank the following one-base point mutations (from most likely to least likely) with respect to their likelihood of affecting the structure of the corresponding polypeptide. Question 60 options: 2) 4, 3, 2, 1

2) 4, 3, 2, 1

How does termination of translation take place? Question 49 options: 1) The end of the mRNA molecule is reached. 2) A stop codon is reached. 3) The 5' cap is reached. 4) The poly-A tail is reached.

2) A stop codon is reached.

Refer to the figure above. What would the anticodon be for a tRNA that transports phenylalanine to a ribosome? Question 9 options: 1) UUU 2) AAA 3) TTT 4) CCC

2) AAA

What must occur before a newly made polypeptide is secreted from a cell? Question 43 options: 2) Its signal sequence must target it to the ER, after which it goes to the Golgi.

2) Its signal sequence must target it to the ER, after which it goes to the Golgi.

Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer in eukarotes? Question 15 options: 2) Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.

2) Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.

In the process of transcription, _____. Question 12 options: 2) RNA is synthesized

2) RNA is synthesized

In eukaryotes there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein? Question 20 options: 2) RNA polymerase II

2) RNA polymerase II

Which of the following statements best describes the termination of transcription in prokaryotes? Question 19 options: 2) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.

2) RNA polymerase transcribes through the terminator sequence, causing the polymerase to separate from the DNA and release the transcript.

Codons are part of the molecular structure of _____. Question 13 options: 2) mRNA

2) mRNA

There are sixty-one mRNA codons that specify an amino acid, but only forty-five tRNAs. This is best explained by the fact that _____. Question 34 options: 2) the rules for base pairing between the third base of a codon and tRNA are flexible

2) the rules for base pairing between the third base of a codon and tRNA are flexible

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is _____. Question 2 options: 1) 3' UCA5'

3' UCA5'

Translation requires _____. Question 44 options: 1) mRNA, tRNA, DNA, and rRNA 2) mRNA, DNA, and rRNA 3) mRNA, tRNA, and rRNA 4) mRNA, tRNA, and DNA

3) mRNA, tRNA, and rRNA

Refer to the metabolic pathway illustrated above. If A, B, and C are all required for growth, a strain mutant for the gene-encoding enzyme B would be able to grow on medium supplemented with _____. 3) nutrient C only

3) nutrient C only

Transcription in eukaryotes requires which of the following in addition to RNA polymerase? Question 21 options: 3) several transcription factors

3) several transcription factors

Which of the following is directly related to a single amino acid? Question 11 options: 3) the three-base sequence of mRNA

3) the three-base sequence of mRNA

Put the following events of elongation in prokaryotic translation in chronological order. Question 48 options: 1) 1, 2, 3, 4, 5 2) 2, 1, 4, 3, 5 3) 5, 4, 3, 2, 1 4) 1, 2, 3, 5, 4

4) 1, 2, 3, 5, 4

A signal peptide _____. C) helps target a protein to the ER

C) helps target a protein to the ER

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3'(mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.The anticodon loop of the first tRNA that will complement this mRNA is Question 39 options: 1) 3' GGC 5'

1) 3' GGC 5'

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following? Question 3 options: 1) A gene from an organism can theoretically be expressed by any other organism.

1) A gene from an organism can theoretically be expressed by any other organism.

Which of the following best describes the significance of the TATA box in eukaryotic promoters? Question 22 options: 1) It is the recognition site for a specific transcription factor.

1) It is the recognition site for a specific transcription factor.

How might a single base substitution in the sequence of a gene affect the amino acid sequence of a protein encoded by the gene, and why? Question 57 options: 1) Only a single amino acid could change, because the reading frame is unaffected.

1) Only a single amino acid could change, because the reading frame is unaffected.

The tRNA shown in the figure above has its 3' end projecting beyond its 5' end. What will occur at this 3' end? Question 42 options: 1) The amino acid binds covalently.

1) The amino acid binds covalently.

Which of the following DNA mutations is most likely to damage the protein it specifies? Question 54 options: 1) a base-pair deletion

1) a base-pair deletion

The release factor (RF) _____. Question 37 options: 1) binds to the stop codon in the A site in place of a tRNA

1) binds to the stop codon in the A site in place of a tRNA

Once a peptide has been formed between the amino acid attached to the tRNA in the P site and the amino acid associated with the tRNA in the A site, what occurs next? Question 46 options: 1) translocation

1) translocation

Which one of the following statements about RNA processing is true? Question 29 options: 2) Ribozymes may function in RNA splicing.

2) Ribozymes may function in RNA splicing.

A single base substitution mutation is least likely to be deleterious when the base change results in _____. Question 59 options: 2) a codon that specifies the same amino acid as the original codon

2) a codon that specifies the same amino acid as the original codon

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product? Question 52 options: 2) deletion of two nucleotides

2) a deletion of two nucleotides

A ribozyme is _____. Question 24 options: 2) an RNA with catalytic activity

2) an RNA with catalytic activity

Alternative RNA splicing _____. Question 25 options: 2) can allow the production of proteins of different sizes and functions from a single mRNA

2) can allow the production of proteins of different sizes and functions from a single mRNA

Which of the following occurs in prokaryotes but not in eukaryotes? Question 18 options: 2) concurrent transcription and translation

2) concurrent transcription and translation

What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure above? Question 40 options: 2) hydrogen bonding between base pairs

2) hydrogen bonding between base pairs

A primary transcript in the nucleus of a eukaryotic cell is _____ the functional mRNA, while a primary transcript in a prokaryotic cell is _____ the functional mRNA. Question 30 options: 2) larger than; the same size as

2) larger than; the same size as

Use the following information to answer the question(s) below.A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3'(mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.The dipeptide that will form will be _____. Question 38 options: 2) proline-threonine

2) proline-threonine

A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine. The consequence of this for the cell will be that _____. Question 33 options: 2) proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU

2) proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU

The figure above shows a simple metabolic pathway. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway? Question 4 options: 2) 2

2) 2

Use this model of a eukaryotic transcript to answer the following question(s).E = exon and I = intron 5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3' Which components of the previous molecule will also be found in mRNA in the cytosol? Question 28 options: 3) 5' UTR E1 E2 E3 E4 UTR 3'

3) 5' UTR E1 E2 E3 E4 UTR 3'

Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression? Question 23 options: 3) A cap is added to the 5' end of the mRNA. .

3) A cap is added to the 5' end of the mRNA.

During elongation, which site in the ribosome represents the location where a codon is being read? Question 45 options: 3) A site

3) A site

Which one of the following, if missing, would usually prevent translation from starting? Question 47 options: 1) exon 2) 5' cap 3) AUG codon 4) poly-A tail

3) AUG codon

Of the following, which is the most current description of a gene? Question 56 options: 3) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide

3) a DNA sequence that is expressed to form a functional product: either RNA or polypeptide

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. This results in _____. Question 55 options: 3) a polypeptide missing an amino acid

3) a polypeptide missing an amino acid

According to the central dogma, what molecule should go in the blank?DNA → _____ → Proteins Question 16 options: 3) mRNA

3) mRNA

A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be _____. Question 7 options: 1) 5' TTG-CTA-CAG-TAG 3' 2) 5' AUG-CTG-CAG-TAT 3' 3) 3' AAA-AAT-ATA-ACA 5' 4) 3' AAA-GAA-TAA-CAA 5'

4) 3' AAA-GAA-TAA-CAA 5'

Which of the following contradicts the one-gene, one-enzyme hypothesis? Question 10 options: 4) A single antibody gene can code for different related proteins, depending on the splicing that takes place post-transcriptionally.

4) A single antibody gene can code for different related proteins, depending on the splicing that takes place post-transcriptionally.

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is _____. Question 31 options: 4) AAA

4) AAA

Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare? Question 17 options: 4) Codons are a nearly universal language among all organisms.

4) Codons are a nearly universal language among all organisms.

What does it mean when we say the genetic code is redundant? 4) More than one codon can specify the addition of the same amino acid.

4) More than one codon can specify the addition of the same amino acid.

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed its 5' cap and poly-A tail. Which of the following would you expect her to find? Question 27 options: 4) The molecule is digested by enzymes because it is not protected at the 5' end.

4) The molecule is digested by enzymes because it is not protected at the 5' end.

The figure above represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid? Question 41 options: 4) UUC

4) UUC

Post-translational modifications of proteins may include the _____. Question 50 options: 4) addition of carbohydrates to form a glycoprotein

4) addition of carbohydrates to form a glycoprotein

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the _____. Question 32 options: 4) binding of the anticodon to the codon and the attachment of amino acids to tRNAs

4) binding of the anticodon to the codon and the attachment of amino acids to tRNAs

What amino acid sequence will be generated, based on the following mRNA codon sequence?5' AUG-UCU-UCG-UUA-UCC-UUG 3' Question 8 options: 1) met-arg-glu-arg-glu-arg 2) met-glu-arg-arg-glu-leu 3) met-ser-leu-ser-leu-ser 4) met-ser-ser-leu-ser-leu

4) met-ser-ser-leu-ser-leu

Which of the following is the first event to take place in translation in eukaryotes? Question 35 options: 4) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA

4) the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA

An original section of DNA has the base sequence AGCGTTACCGT. A mutation in this DNA strand results in the base sequence AGGCGTTACCGT. This change represents _____. Question 58 options: 4) frameshift mutation

4) frameshift mutation

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because _____. Question 1 options: 4) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes

genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes

Refer to the metabolic pathway illustrated above. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on medium supplemented with _____. 2) nutrient B only

nutrient B only