Chapter 14

Examine the simple metabolic pathway in the figure. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway? 0 1 2 3 It cannot be determined from the pathway.

2

The anticodon loop of the first tRNA that will complement this mRNA is 3' GGC 5'. 5' UGC 3' .5' ACG 3'. 5' GGC 3'. 3' UGC 5'.

3' GGC 5'.

Given the locally unwound double strand in the figure, in which direction does the RNA polymerase move? 5' → 3' along the template strand 3' → 5' along the complementary strand 3' → 5' along the template strand 5' → 3' along the double-stranded DNA 5' → 3' along the complementary strand

3' → 5' along the template strand

Examine the table of codons in the figure. A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be 5'-AUG-CTG-CAG-TAT-3'. 3'-AAC-GAC-GUC-AUA-5'. 3'-AAA-GAA-TAA-CAA-5'. 5'-TTG-CTA-CAG-TAG-3'. 3'-AAA-AAT-ATA-ACA-5'.

3'-AAA-GAA-TAA-CAA-5'.

The direction of synthesis of an RNA transcript is _____.

5' —> 3'

Examine the table of codons in the figure. A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide? 3'-UUU-CCC-AAA-GGG-UUU-CCC 3'-AUG-AAA-GGG-TTT-CCC-AAA-GGG 5'-GGG-AAA-TTT-AAA-CCC-ACT-GGG 5'-ACT-TAC-CAT-AAA-CAT-TAC-UGA 5'-TTT-CCC-AAA-GGG-TTT-CCC

5'-TTT-CCC-AAA-GGG-TTT-CCC

Which of the following statements about mutations is false? An addition mutation results in an added base in the DNA sequence. A knock-out mutation results in a total absence of the mutated protein. A deletion mutation results in the loss of a base in the DNA sequence. Addition and deletion mutations disrupt the primary structure of proteins.

A knock-out mutation results in a total absence of the mutated protein.

Which three statements correctly describe the processing that takes place before a mature mRNA exits the nucleus? A poly-A tail (50-250 adenine nucleotides) is added to the 3' end of the pre-mRNA. A cap consisting of a modified guanine nucleotide is added to the 5' end of the pre-mRNA. A translation stop codon is added at the 3' end of the pre-mRNA. Noncoding sequences called introns are spliced out by molecular complexes called spliceosomes. Coding sequences called exons are spliced out by ribosomes.

A poly-A tail (50-250 adenine nucleotides) is added to the 3' end of the pre-mRNA. A cap consisting of a modified guanine nucleotide is added to the 5' end of the pre-mRNA. Noncoding sequences called introns are spliced out by molecular complexes called spliceosomes.

Transcription begins at a promoter. What is a promoter? Part of the RNA molecule itself A site in DNA that recruits the RNA Polymerase The same as a start codon A site found on the RNA polymerase

A site in DNA that recruits the RNA Polymerase

At which site do new aminoacyl tRNAs enter the ribosome during elongation? E-site B-site P-site A-site

A-site

start/methionine codon

AUG

Which of the following molecules is/are produced by translation? Include molecules that are subject to further modification after initial synthesis. The amino acid glycine Aminoacyl-tRNA synthetase RNA polymerase

Aminoacyl-tRNA synthetase RNA polymerase

If a mutated DNA sequence produces a protein that differs in one central amino acid from the normal protein, which of the following kinds of mutations could have occurred? None. An addition mutation An addition mutation and a deletion mutation. A deletion mutation.

An addition mutation and a deletion mutation.

Which of these is a tRNA?

B

What determines which base is to be added to an RNA strand during transcription? The previous base Base pairing between the two DNA strands The order of the chemical groups in the backbone of the RNA molecule Base pairing between the DNA template strand and the RNA nucleotides

Base pairing between the DNA template strand and the RNA nucleotides

The tRNA anticodon, GAC, is complementary to the mRNA codon with the sequence ____

CUG

Which of the following terms best describes the relationship between the newly synthesized RNA molecule and the DNA template strand? Complementary Covalently bound Identical Permanently base-paired

Complementary

In the diagram below, the green unit represents _____. RNA DNA transcription factors RNA polymerase the promote

DNA

Which of the following mutations would likely be most dangerous to a cell? Deletion of one nucleotide Deletion of three nucleotides Substitution of one nucleotide for another

Deletion of one nucleotide

If a DNA sequence is altered from TAGCTGA to TAGTGA, what kind of mutation has occurred? Deletion. Both addition and deletion. Addition. None.

Deletion.

insulin

ER-Golgi-outside cell

True or false. A tRNA with an anticodon complementary to the stop codon catalyzes the reaction by which translation is terminated.

False

True or false? A codon is a group of three bases that can specify more than one amino acid.

False

amino acid

GCA AAA CAC UGC ACU AUC

Which of these correctly illustrates the pairing of DNA and RNA nucleotides? GTTACG CAATCG GTTACG CAAUGC GTTACG GTTACG GTTACG ACCGTA GTTACG UAACAU

GTTACG CAAUGC

Which of the following statements is/are correct? In some genes, intron RNA functions as a ribozyme and catalyzes its own excision. A ribosome can be regarded as one large ribozyme. Ribozymes are RNA molecules that function as enzymes.

In some genes, intron RNA functions as a ribozyme and catalyzes its own excision. A ribosome can be regarded as one large ribozyme. Ribozymes are RNA molecules that function as enzymes.

Part complete What happens to RNA polymerase II after it has completed transcription of a gene? It begins transcribing the next gene on the chromosome. It is degraded. It is free to bind to another promoter and begin transcription. It joins with another RNA polymerase to carry out transcription.

It is free to bind to another promoter and begin transcription.

Which of the following molecules are produced by transcription? Messenger RNA Ribosomal proteins Ribozymes

Messenger RNA Ribozymes

During translation, nucleotide base triplets (codons) in mRNA are read in sequence in the 5' → 3' direction along the mRNA. Amino acids are specified by the string of codons. What amino acid sequence does the following mRNA nucleotide sequence specify? 5′−AUGGCAAGAAAA−3′

Met-Ala-Arg-Lys

What amino acid sequence does the following DNA nucleotide sequence specify? 3′−TACAGAACGGTA−5′

Met-Ser-Cys-His

The average length of a transcription unit along a eukaryotic DNA molecule is about 27,000 nucleotide pairs, whereas an averaged-sized protein is about 400 amino acids long. What is the best explanation for this fact? Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated. Each amino acid in a protein is encoded by a triplet of nucleotides. Many genes are subject to alternative RNA splicing.

Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated.

Which mutation(s) would not change the remainder of the reading frame of a gene sequence that follows the mutation(s)? One deletion mutation. One addition and one deletion mutation. One addition and two deletion mutations. One addition mutation.

One addition and one deletion mutation.

DNA does not store the information to synthesize which of the following? Proteins Messenger RNA DNA Organelles

Organelles

The initiator tRNA attaches at the ribosome's _____ site. A translocation E P Q

P

Which of the following processes is an example of a post-translational modification? Initiation Elongation Phosphorylation Peptide bond formation

Phosphorylation

In the diagram below, the gray unit represents _____. RNA DNA transcription factors RNA polymerase the promoter

RNA polymerase

Place the events in the transcription of a gene in their proper order from left (first event) to right (last event).

RNA polymerase binds promoter. RNA polymerase transcribes gene. RNA polymerase reaches terminator. RNA polymerase exits gene, RNA is released.

Part complete What name is given to the process in which pre-mRNA is edited into mRNA? RNA processing gene expression polypeptide formation transcription translation

RNA processing

Part complete Where does translation take place? Nucleus Endoplasmic reticulum Golgi apparatus Ribosome

Ribosome

of translation happens when the ribosome hits a stop codon on the mRNA.

Termination

The tRNA shown in the figure has its 3' end projecting beyond its 5' end. What will occur at this 3' end? The codon and anticodon will complement one another. The 5' cap of the mRNA will become covalently bound. The small and large subunits of the ribosome will attach to it. The amino acid will bind covalently.

The amino acid will bind covalently.

Which of the following steps occurs last in the initiation phase of translation? The large ribosomal subunit joins the complex. The small subunit of the ribosome binds to the 5' cap on the mRNA. An aminoacyl tRNA binds to the start codon. A peptide bond is formed between two adjacent amino acids.

The large ribosomal subunit joins the complex.

Which of the following statements best describes the promoter of a protein-coding gene? The promoter is a site at which only RNA polymerase will bind. The promoter is a site found on RNA polymerase. The promoter is part of the RNA molecule itself. The promoter is a nontranscribed region of a gene.

The promoter is a nontranscribed region of a gene.

What is meant by translocation? The ribosome slides one codon down the mRNA. The completed polypeptide is released from the ribosome. The two ribosomal subunits are joined in a complex. The polypeptide chain grows by one amino acid.

The ribosome slides one codon down the mRNA.

What is the process called that converts the genetic information stored in DNA to an RNA copy? Translation Transcription Replication Translocation

Transcription

If the sequence ATGCATGTCAATTGA were mutated such that a base were inserted after the first G and the third T were deleted, how many amino acids would be changed in the mutant protein? Three. None. One. Two

Two

stop codon

UAA UAG UGA

Suppose that a portion of double-stranded DNA in the middle of a large gene is being transcribed by an RNA polymerase. As the polymerase moves through the sequence of six bases shown in the diagram below, what is the corresponding sequence of bases in the RNA that is produced?

UGAGCC

the figure 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? UUC CAU GUA UGG GUG

UUC

During RNA processing a(n) _____ is added to the 3' end of the RNA. 3' untranslated region a long string of adenine nucleotides 5' untranslated region coding segment modified guanine nucleotide

a long string of adenine nucleotides

Based on the genetic code chart above, which of the following would be the result of this single base-pair substitution? a nonsense mutation resulting in early termination of translation a silent mutation (no change in the amino acid sequence of the protein) a frameshift mutation causing a single amino acid change in the protein a missense mutation causing a single amino acid change in the protein a frameshift mutation causing extensive change in the amino acid sequence of the protein

a nonsense mutation resulting in early termination of translation

Polypeptides are assembled from _____. hexoses glycerol nucleotides proteins amino acids

amino acids

Part complete What enzyme catalyzes the attachment of an amino acid to tRNA? aminoacyl-tRNA synthetase rubisco dextrinase argininosuccinate lyase nuclease

aminoacyl-tRNA synthetase

4. Amino acids are attached to tRNA by enzymes called

aminoacyl-tRNA synthetase.

Examine the simple metabolic pathway in the figure. A mutation results in a defective enzyme 1. Which of the following results would be a consequence of that mutation? an accumulation of B and C and no production of A an accumulation of A and no production of B and C an accumulation of B and no production of A and C an accumulation of C and no production of A and B an accumulation of A and B and no production of C

an accumulation of A and no production of B and C

tRNA

contains an anticodon, has amino acids covalently attached

mRNA

contains exons, specifies the amino acid sequence for a protein

Translation occurs in the _____. cytoplasm lysosome nucleus Golgi apparatus nucleoplasm

cytoplasm

PFK

cytoplasm only

The RNA segments joined to one another by spliceosomes are _____. caps exons snRNPs tails introns

exons

What type of bonding is responsible for maintaining the shape of the tRNA molecule in the figure? hydrogen bonding between base pairs peptide bonding between amino acids van der Waals interactions between hydrogen atoms covalent bonding between sulfur atoms ionic bonding between phosphates

hydrogen bonding between base pairs

What is the name of the process shown in the diagram? initiation (of transcription) RNA processing initiation (of translation) elongation termination (of translation)

initiation (of translation)

rRNA

is the most abundant form of RNA, is a component of ribosomes

RNA processing converts the RNA transcript into _____. a protein DNA a eukaryotic cell mRNA a polypeptide

mRNA

Transcription/RNA processing

mRNA

Which nucleic acid is translated to make a protein? mRNA DNA tRNA rRNA

mRNA

Examine the table of codons in the figure. What amino acid sequence will be produced based on the following mRNA codon sequence?5'-AUG-UCU-UCG-UUA-UCC-UUG-3' met-glu-arg-arg-glu-leu met-ser-leu-ser-leu-ser met-leu-phe-arg-glu-glu met-ser-ser-leu-ser-leu met-arg-glu-arg-glu-arg

met-ser-ser-leu-ser-leu

During RNA processing a(n) _____ is added to the 5' end of the RNA. 3' untranslated region a long string of adenine nucleotides 5' untranslated region coding segment modified guanine nucleotide

modified guanine nucleotide

exon 1 exon 2 intron 2 exon 3

mutation in a splicing signal sequence in intron 2

no mRNA produced

mutation in the gene's promoter sequence

exon 1 intron 1 exon 2 intron 2 exon 3

mutations in splicing sequences in both intron 1 and intron 2

exon 1 exon 2 exon 3

no mutation in any splicing sequence

Initiation

of translation always happens at the start codon of the mRNA.

The dipeptide that will form will be alanine-alanine. threonine-glycine. glycine-cysteine. proline-threonine. cysteine-alanine

proline-threonine

Which of the following terms associated with transcription describe regions of nucleic acid? promoter gene terminator RNA polymerase

promoter gene terminator

Part complete Spliceosomes are composed of _____. small RNAs and proteins polymerases and ligases introns and exons the RNA transcript and protein

small RNAs and proteins

The RNA that has an amino acid attached to it, and that binds to the codon on the mRNA, is called a

tRNA

Translation

tRNA, rRNA

For any given gene, what ultimately determines which DNA strand serves as the template strand? which of the two strands of DNA carries the RNA primer the location of specific proteins (transcription factors) that bind to the DNA the base sequence of the gene's promoter the location along the chromosome where the double-stranded DNA unwinds

the base sequence of the gene's promoter

In the transcription event of the DNA in the figure, where would the promoter be located? at the 3' end of the newly made RNA to the right of the template strand to the left of the sense strand to the right of the sense strand to the left of the template strand

to the right of the template strand

What name is given to the process in which a strand of DNA is used as a template for the manufacture of a strand of pre-mRNA? RNA processing gene expression polypeptide formation transcription translation

transcription

. The process, performed by the ribosome, of reading mRNA and synthesizing a protein is called

translation

What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein? RNA processing gene expression polypeptide formation transcription translation

translation