Chapter 17: Gene Expression

Which of the following is a post-translational modification of a polypeptide? - Formation of a polysome that allows simultaneous formation of many polypeptides from one mRNA transcript - The growing polypeptide signals the ribosome to attach to the ER - Complementary base pairing of mRNA and tRNA in the ribosome - Removal of introns and splicing of exons - Cleavage of a polypeptide into two or more chains

- Cleavage of a polypeptide into two or more chains

What is a key difference in gene expression between eukaryotic and prokaryotic cells? - Prokaryotes do not contain ribosomes. - In prokaryotes, proteins are assembled directly from DNA. - RNA polymerases are involved only in initiation in eukaryotes. - In eukaryotic cells, transcribed RNA sequences function as termination signals. - In prokaryotic cells, the mRNA transcript is immediately available as mRNA without processing.

- In prokaryotic cells, the mRNA transcript is immediately available as mRNA without processing.

Which of the following best describes the arrangement of genetic information in a DNA molecule? - The three-nucleotide words of a gene are serially arranged on both strands of DNA at a specific locus. - A gene is composed of overlapping, three-nucleotide words on a template strand of DNA. - By overlapping the three-nucleotide words of a gene, the amount of information a DNA molecule can hold is maximized. - The three-nucleotide words of a gene are arranged in a nonoverlapping series on the DNA template strand. - By analyzing the linear order of amino acids in a polypeptide, the exact order of the three-nucleotide words of a gene arranged on the template strand of DNA can be determined.

- The three-nucleotide words of a gene are arranged in a nonoverlapping series on the DNA template strand.

Stop codons are unique because they __________. - do not code for amino acids that allow a releasing factor to bind to the P site of the ribosome - do not code for amino acids that allow a releasing factor to bind to the A site of the ribosome - do not code for amino acids that allow a releasing factor to bind to the E site of the ribosome - code for releasing factors - code for a specific amino acid that binds to a releasing factor

- do not code for amino acids that allow a releasing factor to bind to the A site of the ribosome

The TATA box is a __________ that allows for the binding of __________ and __________. - eukaryotic promoter; transcription factors; ribozymes - prokaryotic promoter; translation factors; ribosome - eukaryotic promoter; transcription factors; RNA polymerase II - prokaryotic promoter; transcription factors; RNA polymerase II - eukaryotic promoter; translation factors; ribosome

- eukaryotic promoter; transcription factors; RNA polymerase II

An exception to the one gene-one enzyme hypothesis is __________. - that not all genes code for enzymes; some genes code for structural proteins such as keratin - None of the listed responses is correct. - that not all amino acids code for enzymes; some amino acids code for structural proteins such as keratin - that all genes code for enzymes that produce structural proteins such as keratin - that the genetic code is for enzymes, while the structural code is for structural proteins such as keratin

- that not all genes code for enzymes; some genes code for structural proteins such as keratin

Eukaryotic processing of the primary transcript includes __________. - the addition of a 5ꞌ cap, a 3ꞌ poly-A tail, and the splicing out of exons - the addition of a 5ꞌ cap, a 3ꞌ poly-A tail, and the splicing out of introns - the addition of a 5ꞌ poly-A tail, a 3ꞌ cap, and the splicing out of introns - the addition of a 5ꞌ poly-A tail, a 3ꞌ cap, and the splicing out of exons - the addition of a 5ꞌ cap, a 3ꞌ poly-A tail, the splicing out of introns, and a polyadenylation signal

- the addition of a 5ꞌ cap, a 3ꞌ poly-A tail, and the splicing out of introns

Bacteria can transcribe and translate human genes to produce functional human proteins because __________. - bacterial and eukaryotic RNA polymerases are identical - RNA has catalytic properties - bacterial ribosomes and eukaryotic ribosomes are identical - eukaryotes do not really need a nucleus - the genetic code is nearly universal

- the genetic code is nearly universal

Gene expression is __________. - the way that some genes express themselves at different times of the day, giving an individual a new appearance - the genetic makeup of an individual - the process by which DNA directs the synthesis of proteins - None of the listed responses is correct. - the way that an individual appears

- the process by which DNA directs the synthesis of proteins

The "triplet code" refers to the fact that _________. - None of the listed responses is correct. - the three-letter code for each amino acid is a triplet - three sets of nucleotides are required for each amino acid - three amino acids code for a single nucleotide - three nucleotides code for a single amino acid

- three nucleotides code for a single amino acid

What is the proper order of the following events in the expression of a eukaryotic gene? 1. translation 2. RNA processing 3. transcription 4. modification of protein 1, 2, 4, 3 4, 2, 3, 1 1, 2, 3, 4 2, 3, 4, 1 3, 2, 1, 4

3, 2, 1, 4

How many nucleotides are needed to code for a protein with 450 amino acids? At least 450 At least 300 At least 150 At least 1,350 At least 900

At least 1,350

Who formulated the one gene-one enzyme hypothesis? Franklin Hershey and Chase Beadle and Tatum Watson and Crick None of the listed responses is correct.

Beadle and Tatum

Genetic information of eukaryotic cells is transferred from the nucleus to the cytoplasm in the form of __________. carbohydrates RNA lipids proteins

RNA

Which of the following catalyzes the linkage between ribonucleotides to form RNA during gene expression? RNA ligase RNA polymerase Reverse transcriptase tRNA A ribozyme

RNA polymerase

__________ is the synthesis of RNA using information in the DNA. The polypeptide hypothesis Transcription Splicing Translation Alternative splicing

Transcription

When RNA is being made, the RNA base _________ always pairs with the base __________ in DNA. A; U T; A T; G U; A U; T

U; A

Because the bacterial cell's DNA is not surrounded by a nuclear envelope, __________ occur(s). coupled transcription and translation alternative splicing segregated transcription and translation coupled splicing and tailing of the message segregated splicing and tailing of the message

coupled transcription and translation

The function of tRNA during protein synthesis is to __________. - process mRNA - attach mRNA to the small subunit of the ribosome - guide ribosome subunits out of the nucleus through nuclear pores - transcribe mRNA - deliver amino acids to their proper site during protein synthesis

deliver amino acids to their proper site during protein synthesis

Insertions and deletions are called __________ mutations. nonsense nucleotide-pair substitution missense frameshift silent

frameshift

Polysomes may be defined as __________. microfilaments and microtubules groups of peroxisomes groups of ribosomes groups of lysosomes groups of chromosomes

groups of ribosomes

The bonds that hold tRNA molecules in the correct three-dimensional shape are __________. hydrophobic interactions covalent bonds hydrogen bonds ionic bonds peptide linkages

hydrogen bonds

The sickle-cell β-globin mutation is an example of a __________. pointless mutation base deletion missense mutation nonsense mutation silent mutation

missense mutation

The type of point mutation that results in a premature stop codon is called a _________ mutation. nonsense inversion missense silent deletion

nonsense

By bombarding the fungus Neurospora crassa with X-rays, Beadle and Tatum were able to study __________ and characterize enzymes in a __________. phenotypic mutants; glycolysis nutritional mutants; glycolysis nutritional mutants; biochemical pathway wild-type mutants; biochemical pathway phenotypic mutants; biochemical pathway

nutritional mutants; biochemical pathway

The structures called snRNPs are __________. a critical component of the initiation complex part of a spliceosome a type of specialized carbohydrate All of the listed responses are correct. involved in the removal of exons from DNA

part of a spliceosome

One strand of a DNA molecule has the following sequence: 3-AGTACAAACTATCCACCGTC-5. In order for transcription to occur in that strand, there would have to be a specific recognition sequence, called a(n) __________, to the left of the DNA sequence indicated. intron centromere promoter AUG codon exon

promoter

RNA molecules that function as enzymes are called __________. transfer RNAs aminoacyl-RNA synthetases ribozymes polysomes RNA polymerases

ribozymes

In eukaryotic cells, a __________ by a __________ targets a growing peptide to the endoplasmic reticulum. ribosome; signal-recognition particle signal-recognition particle; signal peptide signal-recognition particle; ribosome signal peptide; polyribosome signal peptide; signal-recognition particle

signal peptide; signal-recognition particle

__________ is the synthesis of a polypeptide using information in the mRNA. Alternative splicing Transcription Translation The polypeptide hypothesis Splicing

translation