Chapter 10 Quiz

A template DNA strand contains 30% A, 20%T, 27% G, and 23% C. The RNA transcript contains A. 30% U, 20% A, 27% C, and 23% G. B. 30% T, 20% A, 27% C, and 23% G. C. 30% A, 20% T, 27% G, and 23% C. D. 30% A, 20% U, 27% G, and 23% C.

A. 30% U, 20% A, 27% C, and 23% G.

Which of the following is true about the structure of a double-stranded DNA molecule? A. The diameter of a DNA molecule is the same along its entire length due to the specific complementary base pairing of the DNA nucleotides B. The nucleotides in a strand of DNA are held together by hydrogen bonds C. Purine nucleotides always form base pairs with other purines, and pyrimidine nucleotides always form base pairs with other pyrimidines D. The nitrogenous bases in one strand are held to the nitrogenous bases of the other strand by phosphodiester bonds

A. The diameter of a DNA molecule is the same along its entire length due to the specific complementary base pairing of the DNA nucleotides

Imagine that your lab is synthesizing a new type of cell. One of your colleagues suggests that your synthetic cell should use prokaryotic systems for all the steps of gene expression (transcription and translation) because prokaryotic protein synthesis is faster than eukaryotic protein synthesis. What characteristics of prokaryotic transcription and translation make the overall process faster than in eukaryotes? Select all that apply. A. The primary transcript in prokaryotes does not undergo further processing, so translation can begin immediately. B. Prokaryotes lack a nuclear envelope, so translation can begin on an mRNA even before transcription of the mRNA is complete. C. The smaller ribosomes of prokaryotes can move across the mRNA faster. D. Multiple proteins can be synthesized from a single mRNA molecule. E. Because prokaryotes use fewer codons, there are fewer tRNAs to sort through. F. The circular chromosome of prokaryotes makes it easier (and faster) for RNA polymerase to identify genes for transcription.

A. The primary transcript in prokaryotes does not undergo further processing, so translation can begin immediately. B. Prokaryotes lack a nuclear envelope, so translation can begin on an mRNA even before transcription of the mRNA is complete. D. Multiple proteins can be synthesized from a single mRNA molecule.

You are investigating an abnormal eukaryotic cell line that makes all of its mRNAs much longer than the mRNAs from normal cells. Intrigued, you examine the proteins in these abnormal cells and note that many of them are either much longer or much shorter than the normal proteins from nonmutant cells. Assuming there is just one mutant defect in these cells, which of the below possibilities is most likely? A. The spliceosome is nonfunctional. B. A stop codon is mutated. C. The release factor is defective. D. The enzyme that adds the poly-A tail is defective. E. RNA polymerase does not recognize the terminator sequence.

A. The spliceosome is nonfunctional.

What will happen when the ribosome shifts one codon further on the mRNA, assuming the next codon is not a stop codon? Select all that apply. UAC CAU AUG GUA Met-Val A. The tRNA carrying the polypeptide will be in the P site. B. The tRNA that is shown in the A site in the figure above will be ejected from the ribosome. C. A new tRNA will bind to the ribosome. D. The sites of the ribosomes will be relabeled (from left to right) P, A, E. E. The tRNA that was carrying the polypeptide will be ejected from the ribosome.

A. The tRNA carrying the polypeptide will be in the P site. C. A new tRNA will bind to the ribosome. E. The tRNA that was carrying the polypeptide will be ejected from the ribosome.

In order for a nucleotide to be added to a growing RNA strand, the polymerase ensures that hydrogen bonds between the incoming base and the template strand are properly made before the high-energy phosphate bond is cleaved. A. True B. False

A. True

Many mutations are detrimental to organisms that acquire them, but other mutations are beneficial and allow evolution of that species. A. True B. False

A. True

Some RNA molecules possess catalytic activity. A. True B. False

A. True

Whichever DNA strand is transcribed, the RNA polymerase reads the template strand from 3' to 5' A. True B. False

A. True

In the process of transcription, the RNA transcript is synthesized A. from the 5' end to the 3' end. B. from the 3' end to the 5' end.

A. from the 5' end to the 3' end.

The type of RNA that physically interacts with a ribosome, providing the sequence information for a specific protein, is abbreviated A. mRNA. B. rRNA. C. tRNA.

A. mRNA.

RNA processing occurs in the A. nucleus. B. nucleus and cytoplasm. C. cytoplasm. D. plasma membrane.

A. nucleus.

After translation, the polypeptide chains of some proteins are cut by a process called A. proteolysis. B. phosphorylation. C. glycation. D. glycosylation. E. exonuclease digestion.

A. proteolysis.

The genetic code is A. redundant. B. ambiguous. C. a quadruplet code. D. different for bacteria than for eukaryotes. E. comprised of codons which usually differ at the first position.

A. redundant.

When a peptide bond is created between two amino acids A. the carboxyl group of the first amino acid is joined to the amino group of the second. B. the carboxyl group of the first amino acid is joined to the carboxyl group of the second. C. the amino group of the first amino acid is joined to the amino group of the second. D. the amino group of the first amino acid is joined to the carboxyl group of the second.

A. the carboxyl group of the first amino acid is joined to the amino group of the second.

When DNA or genetic information is passed between bacteria (and bacteria take up this material from their surrounding environment), this process is referred to as A. transformation. B. transcription. C. transmutation. D. translation. E. transferration.

A. transformation.

Which of the following processes occur in the cytoplasm of eukaryotic cells? A. translation only B. transcription and translation C. DNA replication only D. DNA replication and transcription E. DNA replication, transcription, and translation

A. translation only

A template DNA strand contains the sequence 5'-ATGCTGAC-3'. The corresponding sequence in the RNA transcript is A. 5'-GTCAGCAT-3' B. 5'-GUCAGCAU -3' C. 5'-UACGACUG-3' D. 5'-TACGACTG-3'

B. 5'-GUCAGCAU -3'

Which of the following DNA molecules would be more stable under conditions of increasing temperature? A. A DNA molecule that has more adenine and thymine nucleotides B. A DNA molecule that has more guanine and cytosine nucleotides C. Both DNA molecules would be equally stable under conditions of increasing temperature

B. A DNA molecule that has more guanine and cytosine nucleotides

The central dogma of molecular biology states that information flows from A. RNA to protein to DNA. B. DNA to RNA to protein. C. protein to RNA to DNA. D. RNA to DNA to protein. E. DNA directly to protein.

B. DNA to RNA to protein.

All RNA is translated to generate proteins. A. True B. False

B. False

During transcription of a given protein-coding gene, both strands are used as template. A. True B. False

B. False

Which one of the following correctly lists the components necessary for eukaryotic transcription? A. ribosomes, general transcription factors, DNA, and RNA nucleotides B. RNA polymerase, general transcription factors, DNA, and RNA nucleotides C. ribosomes, general transcription factors, DNA, and DNA nucleotides D. RNA polymerase, general transcription factors, DNA, and DNA nucleotides

B. RNA polymerase, general transcription factors, DNA, and RNA nucleotides

10^9 bacterial cells are spread evenly on an agar surface of medium containing an antibiotic. After a few days, a few of the cells grow into small clumps of cells. Isolation of individual bacterial cells and further testing reveals that the clumps consist of mutant bacteria that are resistant to the antibiotic. Which of the following statements is true? A. The mutations occur because they are beneficial in the presence of the antibiotic B. The mutations pre-exist and are selected by the antibiotic C. The mutations are caused by the presence of the antibiotic D. All answers are correct

B. The mutations pre-exist and are selected by the antibiotic

The base uracil pairs with A. guanine. B. adenine. C. cytosine. D. thymine.

B. adenine.

The poly(A) sequence that is added to RNA during processing A. aids in the accuracy of translation of the messenger RNA into protein. B. helps prevent rapid breakdown of the messenger RNA. C. is needed for ribosomes to attach to messenger RNA. D. helps prevent formation of complex three-dimensional structures in the messenger RNA.

B. helps prevent rapid breakdown of the messenger RNA.

Where does energy come from to add a uracil to the 3' end of a transcript? A. the energy released by allowing the uracil to complementary base pair with an adjacent thymine B. the hydrolysis of pyrophosphate from the incoming UTP molecule C. the hydrolysis of all three phosphate groups from the incoming UTP molecule D. the hydrolysis of a terminal phosphate from the incoming UTP molecule E. the cell's supply of ATP

B. the hydrolysis of pyrophosphate from the incoming UTP molecule

How many different types of aminoacyl tRNA synthetases are there? A. 2 B. 4 C. 20 D. 61 E. 64

C. 20

Which of the following is the correct mRNA produced from the transcription of this DNA molecule? 5'-ATGTCAGGTACGCCACAT-3' 3'-TACAGTCCATGCGGTGTA-5' A. 5'-AUGUGGAGUACCUGACAU-3' B. 3'-UACAGUCCAUGAGGUGUA-5' C. 5'-AUGUCAGGUACGCCACAU-3' D. 3'-UACAGUCCAUGCGGUACA-5'

C. 5'-AUGUCAGGUACGCCACAU-3'

Which one of the following statements about RNA is CORRECT? A. RNA has the same 5-carbon sugars as DNA B. RNA uses the same pyrimidine bases as DNA C. RNA uses the same purine bases as DNA D. RNA is a more stable molecule than DNA

C. RNA uses the same purine bases as DNA

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

C. The RNA polymerase would not be able to recognize and bind the DNA, so no RNA would be made

Which one of the following explains why rRNAs are the most abundant type of RNA in a mammalian cell? A. There are more different types of rRNA genes than all other types of genes combined. B. It takes several rRNAs to transcribe a single mRNA, so there are many more rRNAs needed in a cell than the number of proteins synthesized. C. There are rRNAs in ribosomes, and it takes millions of ribosomes to translate all the proteins required for a cell's functions. D. A different type of ribosome is needed to synthesize all of a cell's proteins, and because most proteins are present in multiple copies, a huge number of ribosomes are needed.

C. There are rRNAs in ribosomes, and it takes millions of ribosomes to translate all the proteins required for a cell's functions.

A newly formed protein whose destination is the Golgi apparatus will likely contain A. a polysome. B. a spliceosome. C. a signal sequence. D. directing factors. E. a protein release factor.

C. a signal sequence.

In transcription, the energy to attach each successive ribonucleotide to the growing RNA chain comes from A. cleavage of the high-energy phosphate bonds of the growing transcript. B. cleavage of the 2' hydroxyl group on the ribose of the incoming nucleotide. C. cleavage of the high-energy phosphate bonds of the incoming nucleotide. D. the RNA polymerase itself.

C. cleavage of the high-energy phosphate bonds of the incoming nucleotide.

Which one of the following types of proteins interacts directly with a stop codon? A. initiation factor B. elongation factor C. release factor D. transcription factor

C. release factor

When we say that tRNAs move from the A to P to E sites of a ribosome, what is moving? A. the mRNA B. the tRNA C. the ribosome D. nothing is moving

C. the ribosome

Which of the following cellular processes occurs in the nucleus of a eukaryote? A. transcription B. RNA processing C. transcription and RNA processing D. translation

C. transcription and RNA processing

After translation has been initiated, for how long does elongation go on? A. until the ribosome reaches the end of the mRNA B. until the ribosome reaches the start codon C. until the ribosome reaches a stop codon D. until the ribosome reaches the poly(A) tail of the mRNA E. until the cell runs out of tRNAs

C. until the ribosome reaches a stop codon

A template strand of DNA is read in the _____________________ direction in order to direct synthesis of RNA in the _____________________ direction. A. 3'-5'; 3'-5' B. 5'-3'; 3'-5' C. 5'-3'; 5'-3' D. 3'-5'; 5'-3'

D. 3'-5'; 5'-3'

Which of the following molecules is made during the process of transcription? A. mRNA B. rRNA C. tRNA D. All answers are correct

D. All answers are correct

Why do tetracyclines (a family of antibiotics) kill bacteria but not eukaryotic cells? A. Tetracyclines cannot enter the ER of eukaryotic cells B. Tetracyclines are destroyed by enzymes found only in eukaryotes C. Tetracyclines cannot enter the nucleus of eukaryotic cells D. Bacterial and eukaryotic ribosomes differ in their specific proteins and RNAs E. Bacteria and eukaryotic tRNAs bind different amino acids

D. Bacterial and eukaryotic ribosomes differ in their specific proteins and RNAs

The function of a protein is dependent upon the shape into which the chain of amino acids folds. Many noncovalent interactions are responsible for maintaining the protein's shape. Assume you have isolated a protein from an organism in its proper shape, and you have treated it with an enzyme that selectively targets and breaks only the peptide bonds in the proteins. Would the protein retain its shape under these conditions? A. Yes; once noncovalent bonding determines the shape of a protein, the peptide bonds are no longer necessary. B. Yes; but the shape would be affected to a greater extent by changes in temperature. C. Yes; because the noncovalent interactions that determine the shape of a protein are stronger than the peptide bonds. D. No; while the noncovalent bonds determine the shape of a protein, the peptide bonds are required to hold the amino acids together.

D. No; while the noncovalent bonds determine the shape of a protein, the peptide bonds are required to hold the amino acids together.

Transcription continues until A. a ribosome pulls RNA polymerase off the DNA. B. a transcription factor signals the end of the gene. C. a stop codon is encountered. D. a terminator sequence is encountered. E. all bases in the DNA are copied.

D. a terminator sequence is encountered.

In transcription, each added ribonucleotide comes into the RNA polymerase complex as a A. nucleoside. B. nucleoside monophosphate. C. nucleoside diphosphate. D. nucleoside triphosphate.

D. nucleoside triphosphate.

An exon is A. a protein that is clipped out post-translationally. B. a transfer RNA that binds to the codon. C. RNA that is removed during the processing of an RNA molecule and remains inside the nucleus. D. part of an intact, mature mRNA that leaves the nucleus. E. a series of amino acids at the end of a new polypeptide that directs transcription to the ER.

D. part of an intact, mature mRNA that leaves the nucleus.

Ribosomes in prokaryotes and eukaryotes are A. identical in structure and translate using the same genetic code. B. identical in structure but translate using different genetic codes. C. similar in structure and translate using different genetic codes. D. similar in structure and translate using the same genetic code.

D. similar in structure and translate using the same genetic code.

Which of the following correctly describes the complementary base pairing of adenine in both DNA and RNA? A. Adenine pairs with thymine in both DNA and RNA B. Adenine pairs with uracil in DNA and with thymine in RNA C. Adenine pairs with guanine in DNA and with cytosine in RNA D. Adenine pairs with cytosine in DNA and with guanine in RNA E. Adenine pairs with thymine in DNA and with uracil in RNA

E. Adenine pairs with thymine in DNA and with uracil in RNA

In which of the following cellular processes is RNA involved? A. DNA replication B. Transcription C. Translation D. Splicing E. All answers are correct

E. All answers are correct

RNA polymerase complex can do which of the following? A. separate DNA strands B. restore the original DNA strands C. allow RNA-DNA hybrids to form D. release a finished RNA transcript from a DNA template E. All answers are correct

E. All answers are correct

Transcription is sometimes described as a process in which RNA is "copied" from the template strand of DNA. This statement is potentially misleading because A. RNA nucleotides contain ribose and so cannot be an exact copy of DNA. B. the RNA transcript and the DNA template strand are antiparallel. C. the RNA transcript has a complementary sequence of bases to the template strand. D. RNA molecules contain uracil instead of thymine. E. All answers are correct.

E. All answers are correct.

In what order does a charged tRNA move through the sites of a ribosome? A. The tRNA binds with the E site, then is moved to the P site, then the A site as the ribosome shifts. B. The tRNA binds with the E site, then is moved to the A site, then the P site as the ribosome shifts. C. The tRNA binds with the P site, then is moved to the E site, then the A site as the ribosome shifts. D. The tRNA binds with the P site, then is moved to the A site, then the E site as the ribosome shifts. E. The tRNA binds with the A site, then is moved to the P site, then the E site as the ribosome shifts. F. The tRNA binds with the A site, then is moved to the E site, then the P site as the ribosome shifts.

E. The tRNA binds with the A site, then is moved to the P site, then the E site as the ribosome shifts.

An intron is A. a type of transfer RNA. B. a polypeptide that is clipped out of a larger protein post-translationally. C. part of an intact, mature mRNA that leaves the nucleus. D. part of an RNA transcript that is not present in the DNA template. E. an RNA sequence that is removed during the processing of an RNA molecule in the nucleus.

E. an RNA sequence that is removed during the processing of an RNA molecule in the nucleus.