Mastering Biology-Exam 4: Transcription and Translation

Which of the following steps occurs last in the initiation phase of translation?

The large ribosomal subunit joins the complex.

The anticodon of a particular tRNA molecule is __________.

complementary to the corresponding mRNA codon

Translation occurs in the _____.

cytoplasm

In eukaryotic cells, transcription CANNOT begin until __________.

everal transcription factors have bound to the promoter.

The RNA segments joined to one another by spliceosomes are _____.

exons

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

false, only one amino acid

The flow of information in a cell proceeds in what sequence?

from DNA to RNA to protein

What type of bonding is responsible for maintaining the shape of the tRNA molecule in the figure?

hydrogen bonding between base pairs

What is the name of the process shown in the diagram?

initiation (of translation)

What name is given to the process in which the information encoded in a strand of mRNA is used to construct a protein?

translation

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?

two

Examine the simple metabolic pathway in the figure. According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

2

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is

3' UCA 5'

RNA polymerase moves in which direction along the DNA?

3' to 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

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?

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

At which site do new aminoacyl tRNAs enter the ribosome during elongation?

A

Which of these is currently considered the best definition of a gene?

A gene codes for either a polypeptide or an RNA molecule.

The genetic code is essentially the same for all organisms. Based on this information, one can logically assume which of the following statements to be correct?

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

Which of the following statements about mutations is false?

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

Transcription begins at a promoter. What is a promoter?

A site in DNA that recruits the 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?

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?

Base pairing between the DNA template strand and the RNA nucleotides

The initiator tRNA attaches at the ribosome's _____ site.

P

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

Which of the following processes is an example of a post-translational modification?

Phosphorylation

In the diagram below, the two blue strands represent _____.

DNA

Which component is NOT directly involved in translation?

DNA

Of the following, which is the most current and complete description of a gene?

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

If a DNA sequence is altered from TAGCTGA to TAGTGA, what kind of mutation has occurred?

Deletion.

Where does tRNA #2 move to after this bonding of lysine to the polypeptide?

E site

Which one of the following is true of tRNAs?

Each tRNA binds a particular amino acid

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

False

Which of these correctly illustrates the pairing of DNA and RNA nucleotides?

GTTACG CAAUGC

What is the function of the release factor in translation?

It binds to the stop codon in the A site in place of a tRNA.

Which of the following statements correctly describes alternative RNA splicing?

It can allow the production of proteins of different sizes and functions from a single mRNA.

Which of the following is NOT true of a codon?

It extends from one end of a tRNA molecule.

Which of the following is a function of a poly-A tail in mRNA?

It helps protect the mRNA from degradation by hydrolytic enzymes.

What happens to RNA polymerase II after it has completed transcription of a gene?

It is free to bind to another promoter and begin transcription

Where does RNA polymerase begin transcribing a gene into mRNA?

It starts after a certain nucleotide sequence called a promoter.

What is the function of RNA polymerase?

It unwinds the double helix and adds nucleotides to a growing strand of RNA.

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?

Met-Ala-Arg-Lys

What amino acid sequence does the following DNA nucleotide sequence specify?

Met-Ser-Cys-His

Which mutation(s) would not change the remainder of the reading frame of a gene sequence that follows the mutation(s)?

One addition and one deletion mutation

In the diagram below, the gray unit represents _____.

RNA polymerase

Which of the following statements best describes the termination of transcription in prokaryotes?

RNA polymerase transcribes through the terminator sequence, causing the polymerase to fall off the DNA and release the transcript.

What name is given to the process in which pre-mRNA is edited into mRNA?

RNA processing

The tRNA shown in the figure has its 3' end projecting beyond its 5' end. What will occur at this 3' end?

The amino acid binds covalently.

In comparing DNA replication with RNA transcription in the same cell, which of the following is true only of replication?

The entire template molecule is represented in the product.

Which of the following statements best describes the promoter of a protein-coding gene?

The promoter is a nontranscribed region of a gene.

What is meant by translocation?

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?

Transcription

Which of the following statements is true about protein synthesis in prokaryotes?

Translation can begin while transcription is still in progress.

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

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is

UUU

During RNA processing a(n) _____ is added to the 3' end of the RNA.

a long string of adenine nucleotides

Polypeptides are assembled from _____.

amino acids

What enzyme catalyzes the attachment of an amino acid to tRNA?

aminoacyl-tRNA synthetase

RNA processing converts the RNA transcript into _____.

mRNA

Which nucleic acid is translated to make a protein?

mRNA

Examine the table of codons in the figure. What amino acid sequence will be produced based on the following mRNA codon sequence?

met-ser-ser-leu-ser-leu

Examine the simple metabolic pathway in the figure. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme 1 would be able to grow on which of the following media?

minimal medium supplemented with nutrient B only

During RNA processing a(n) _____ is added to the 5' end of the RNA.

modified guanine nucleotide

Which component of the complex described enters the exit tunnel through the large subunit of the ribosome?

newly formed polypeptide

DNA does not store the information to synthesize which of the following?

organelles

The process of translation in both prokaryotes and eukaryotes requires tRNAs, amino acids, and ribosomal subunits. Which of the following components must also be present for translation to proceed?

protein factors and GTP

Where does translation take place?

ribosome

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

several transcription factors

Spliceosomes are composed of _____.

small RNAs and proteins

Use the table to sort the following ten codons into one of the three bins, according to whether they code for a start codon, an in-sequence amino acid, or a stop codon.

start/met: AUG stop: UAA, UGA, UAG Amino Acid: AAA, CAC, UGC, AUC, ACU, GCA

In the diagram below, the green unit represents _____.

the promoter

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?

transcription