Deck 8: Gene Expression: The Flow of Information From DNA to RNA to Protein

Question 1

A codon is a three-base sequence of

A)mRNA that codes for an amino acid.
B)rRNA that codes for an amino acid.
C)tRNA that codes for an amino acid.
D)DNA that codes for an amino acid.

Answer 1

mRNA that codes for an amino acid.

Question 2

RNA molecules that can act as enzymes and catalyze specific biochemical reactions are known as ________________.

A)donors
B)splice acceptors
C)ribozymes
D)tRNAs
E)restriction enzymes
Blooms Level 1: Remember

Answer 2

ribozymes

Question 3

Which of these is NOT a step in transcription?

A)replication
B)initiation
C)termination
D)elongation

Answer 3

replication

Question 4

A typical example of a genetic system that employs RNA splicing is

A)the genes that code for the segments in an earthworm.
B)the genes responsible for making antibodies in humans.
C)the HIV virus genes.
D)the genes that enable RNA splicing.

Question 5

A sequence of DNA that reads 5' ATGCCTGAATCAGCTTTA 3' should code for ____ amino acids after all the steps of conversion into protein are complete.

A)5
B)6
C)7
D)8

Question 6

A(n) _____________ consists of proteins and small nuclear RNAs forming discrete particles that mediate splicing.

A)holoenzyme
B)splicesome
C)nucleosome
D)ribosome
E)chromosome
Blooms Level 1: Remember

Question 7

Which of these is NOT a character of the genetic code?

A)There are the same number of codons as there are amino acids.
B)The code is used by nearly every living organism.
C)Some amino acids have multiple codons.
D)The code is degenerate.

Question 8

In the usual flow of genetic information (often called the Central Dogma), which of the following best represents the expression of genes?

A)Protein-RNA-DNA
B)DNA-RNA-Protein
C)RNA-DNA-Protein
D)DNA-Protein-RNA

Question 9

There are ______________ usually found in the genetic code.

A)3 start codons and 1 stop codon
B)2 start codons and 2 stop codons
C)1 start codon and 3 stop codons
D)0 start codons and 4 stop codons

Question 10

The pattern or sequence in which a molecule of mRNA is deciphered by a ribosome is called the

A)synthesis platform.
B)code degeneration.
C)peptide transition.
D)reading frame.

Question 11

Nonsense codons are

A)codons that code for multiple amino acids.
B)codons that do not code for an amino acid.
C)codons that can be read forward or backward.
D)start codons.

Question 12

Experiments that are done outside a living cell are describe by the Latin term

A)in vino.
B)in vito.
C)in vivo.
D)in vitro.

Question 13

Charles Yanofsky helped decipher the genetic code working with the _____ biosynthesis genes in _______.

A)leucine Salmonella enteritidis
B)phenylalanine Klebsiella pneumoniae
C)tryptophan Escherichia coli
D)glycine Serratia marcescens

Question 14

The (expressed) sequences within mRNA that code for gene products are called

A)extremes.
B)exons.
C)inclusions.
D)introns.

Question 15

The cellular organelle responsible for protein synthesis is the

A)nucleus.
B)mitochondria.
C)centrioles.
D)ribosome.

Question 16

The retroviruses, including HIV, are unique because they do reverse

A)replication.
B)transcription.
C)splicing.
D)translation.

Question 17

Which of these terms is NOT used as a nickname for a stop codon?

A)emerald
B)amber
C)opal
D)ochre

Question 18

The sequences within mRNA that are spliced out (removed) are called

A)extremes.
B)exons.
C)inclusions.
D)introns.

Question 19

The scientists credited with postulating the basis for the genetic code are

A)Hershey and Chase.
B)Griffith and Avery.
C)Watson and Crick.
D)Cohen and Boyer.

Question 20

How many different amino acids could be coded for using the synthetic mRNA sequence of (5' UGCUGCUGC 3')?

A)0
B)1
C)2
D)3

Question 21

Ribosomes are composed of

A)tRNA and protein.
B)mRNA and protein.
C)rRNA and protein.
D)only proteins folded together.

Question 22

In the modification of eukaryotic mRNA, a "cap" consisting of a/an _________ and a tail consisting of _______ are usually added to the transcript.

A)acetyl group, multiple cytosines
B)multiple guanines, methyl group
C)multiple thymines, acetyl group
D)methyl group, multiple adenines

Question 23

A mutation that is characterized by a change in the DNA sequence, but no change in the resulting protein sequence, is called a

A)frameshift mutation.
B)missense mutation.
C)silent mutation.
D)nonsense mutation.

Question 24

Which of the following statements is true under ordinary conditions?

A)DNA and RNA last only for a short time within a cell.
B)DNA lasts forever within a cell while RNA lasts only for a short time.
C)RNA lasts forever within a cell while DNA lasts only for a short time.
D)RNA and DNA both last forever within a cell.

Question 25

A tRNA that recognizes a nonsense codon and inserts an amino acid where protein synthesis should have stopped is called a

A)nonsense tRNA.
B)suppressor tRNA.
C)revertant tRNA.
D)excision tRNA.

Question 26

The enzyme that makes RNA from a DNA template is

A)RNA-dependent DNA polymerase.
B)DNA-dependent DNA polymerase.
C)DNA-dependent RNA polymerase.
D)RNA-dependent RNA polymerase.

Question 27

Experiments that are done inside a living cell are describe by the Latin term

A)in vino.
B)in vito.
C)in vivo.
D)in vitro.

Question 28

A mutation that changes a codon that originally coded for an amino acid into a stop codon is called a

A)frameshift mutation.
B)missense mutation.
C)silent mutation.
D)nonsense mutation.

Question 29

Drugs like AZT, ddC, or ddI work against the AIDS virus because they

A)destroy viral proteins.
B)prevent the formation of viral mRNA.
C)block the action of viral tRNA.
D)look like nitrogenous bases and block viral reverse transcriptase.

Question 30

Which of these processes are coupled (linked) in prokaryotes but NOT in eukaryotes?

A)transcription and translation
B)replication and transcription
C)replication and translation
D)Replication, transcription, and translation are not separate in prokaryotes

Question 31

Aminoacyl-tRNA synthetase is the enzyme that

A)folds tRNA molecules into their proper configuration.
B)causes tRNA molecules to bind to the aminoacyl site of a ribosome.
C)produces tRNA by "reading" DNA molecules.
D)adds the appropriate amino acid to an uncharged tRNA.

Question 32

A mutation that occurs when a base is inserted into or deleted from a DNA sequence, completely altering the subsequent amino acid sequence, is called a

A)frameshift mutation.
B)missense mutation.
C)silent mutation.
D)nonsense mutation.

Question 33

A mutation that changes a codon sequence, and subsequently changes the amino acid that should have been placed at that point in the polypeptide chain, is called a

A)frameshift mutation.
B)missense mutation.
C)silent mutation.
D)nonsense mutation.

Question 34

Transcription occurs in the ________ and translation occurs in the __________ of eukaryotic cells.

A)nucleus, cytoplasm
B)cytoplasm, nucleus
C)nucleus, nucleus
D)cytoplasm, cytoplasm

Question 35

A bacterial (prokaryotic) ribosome is composed of ______ subunits.

A)20S and 40S
B)30S and 50S
C)40S and 60S
D)50S and 70S

Question 36

RNA polymerase binds to a sequence called a/an ______________ before beginning transcription.

A)promoter
B)operator
C)structural gene
D)replication origin

Question 37

Transcription occurs in the ________ and translation occurs in the __________ of prokaryotic cells.

A)nucleus, cytoplasm
B)cytoplasm, nucleus
C)nucleus, nucleus
D)cytoplasm, cytoplasm

Question 38

A tRNA molecule looks like a compact ____ when it is folded into its functional configuration.

A)G
B)L
C)C
D)P

Question 39

An anticodon is a physical component of a/an _______ molecule.

A)tRNA
B)mRNA
C)rRNA
D)DNA

Question 40

Which enzyme forms peptide bonds between adjacent amino acids during polypeptide synthesis?

A)RNA polymerase
B)phosphotransferase
C)peptidyl transferase
D)ribonuclease

Question 41

Mutations that abolish the function encoded by the wild-type allele are known as

A)null mutations.
B)hypomorphic mutations.
C)hypermorphic mutations.
D)conditional mutations.
E)neomorphic mutations. Blooms Level 2: Understand

Question 42

A neomorphic mutation results in an allele that

A)produces no gene product.
B)produces a nonfunctional gene product.
C)produces novel proteins or cause inappropriate expression resulting in a new phenotype.
D)produces proteins that aggregate with wild-type subunits, inactivating them.
E)produces an altered protein that results in a wild-type phenotype. Blooms Level 2: Understand

Question 43

Assume that for a given gene a mutation creates an allele that functions as a dominant negative.The gene codes for a protein that forms a trimer within the cell.If at least one of the subunits has the mutant structure the entire protein is inactivated.For a heterozygous individual, what percent of the trimers present in the cell will be inactive?

A)100%
B)25%
C)50%
D)6.25%
E)12.5%
Blooms Level 4: Analyze

Question 44

Which of the following is required for initiation of eukaryotic translation?

A)Shine-Dalgarno sequence
B)5' cap
C)3' poly(A) tail
D)N-formylmethionine
E)Introns
Blooms Level 1: Remember

Question 45

A neomorphic dominant mutation in the Antennapedia (Antp) gene of Drosophila causes

A)kinks to form in their tails.
B)shortened tails.
C)total loss of color vision.
D)failure to assemble microtubules during mitosis.
E)growth of a leg from the head region. Blooms Level 2: Understand

Question 46

In the digestive system, some protease enzymes must be secreted as an inactive form and then activated later by proteolytic cleavage once outside of the secreting cell.This is to prevent active proteases from damaging the secreting cells.What is the category of precursor proteins of this type?

A)Ubiquitins
B)Zymogens
C)Glycosides
D)Activins

Question 47

Mutations that result in much less of a protein or a protein with limited function are known as

A)null mutations.
B)hypomorphic mutations.
C)hypermorphic mutations.
D)conditional mutations.
E)neomorphic mutations. Blooms Level 2: Understand

Question 48

Protein synthesis begins with the amino acid ___________ as its codon is the one used as the "start codon" by nearly all organisms.

A)methionine
B)arginine
C)cysteine
D)leucine

Question 49

The appearance of a novel phenotype resulting from the substitution of a single base pair might be due to

A)change in the amino acid sequence only.
B)change in the amount of protein expressed.
C)alteration in a gene that codes for a nontranslated RNA.
D)change in the developmental time or location at which a gene is expressed.
E)All of the choices are possible consequences of a single base pair substitution. Blooms Level 3: Apply