Deck 10: Gene Action: From Dna to Protein

Question 1

To express a gene,DNA is first transcribed into a corresponding strand of

A) mtDNA.
B) rRNA.
C) mRNA.
D) tRNA.
E) siRNA.

Answer 1

C

Question 2

A genetic code word is called a(n)

A) condom.
B) proton.
C) codon.
D) nodoc.
E) amino acid.

Answer 2

C

Question 3

The most likely explanation for the fact that the human genome consists of 3.2 billion bases,and encodes about 20,325 proteins,is that

A) all of the genome encodes protein.
B) the genome includes many copies of the instructions for each type of protein.
C) amino acids encode DNA sequences.
D) much of the genome does not encode protein.
E) each protein is encoded by about 160,000 DNA bases.

Answer 3

D

Question 4

DNA replication is necessary so that

A) transcription can proceed.
B) translation can proceed.
C) genetic information is not lost as the information in DNA sequences is accessed.
D) the cell does not die when it divides.
E) the cell can grow.

Question 5

The nitrogenous base that is in RNA but not in DNA is

A) thymine.
B) thiamine.
C) uracil.
D) urea.
E) adenine.

Question 6

A retrovirus produces an enzyme,called reverse transcriptase,which copies its RNA genome into DNA.This is opposite the central dogma because

A) a virus is not an organism.
B) a virus lacks genetic material.
C) a retrovirus lacks DNA.
D) the central dogma states that DNA is copied into RNA.
E) of the viral mutation rate.

Question 7

Which choice is the correct sequence from smallest to largest?

A) amino acid, peptide, polypeptide, protein
B) protein, polypeptide, peptide, amino acid
C) genome, chromosome, gene, DNA
D) amino acid, DNA, peptide, gene
E) peptide, polypeptide, amino acid, protein

Question 8

RNA differs from DNA in that

A) most of it is single-stranded.
B) it is usually double-stranded.
C) it has thymine instead of uracil.
D) it has deoxyribose instead of ribose.
E) it encodes information but has no other functions.

Question 9

The idea that a DNA sequence is a code for an amino acid sequence was first stated in

A) the paper revealing the genetic code, published in 1963.
B) the paper revealing DNA's structure, published in 1953.
C) the papers revealing the human genome sequence, published in 1953.
D) the papers revealing the human genome sequence, published in 2001.
E) the publication of the first map of single nucleotide polymorphisms.

Question 10

Which of these is not found in RNA?

A) nitrogen
B) phosphate
C) deoxyribose
D) purines
E) ribose

Question 11

In transcription,one DNA strand is transcribed into a(n)_______ RNA strand,which is translated into protein.

A) ribosomal
B) transfer
C) messenger
D) anticodon
E) thymine rich

Question 12

In addition to encoding protein,DNA sequences in the human genome

A) encode fats.
B) control the sequences that encode proteins.
C) encode carbohydrates.
D) encode themselves.
E) rapidly interconvert to RNA.

Question 13

If the percentage of guanine in an mRNA is 25%,the percentage of cytosine

A) is 20%.
B) is 30%.
C) is 60%.
D) is 40%.
E) cannot be determined.

Question 14

An mRNA molecule is also called a(n)

A) intron.
B) transcript.
C) gene.
D) proscript.
E) linguist.

Question 15

Cells replicate DNA

A) during the M phase of the cell cycle.
B) all the time.
C) during the S phase of the cell cycle.
D) only when a person is stressed.
E) more frequently the older a person gets.

Question 16

Which of the following descriptions of genetic information flow best illustrates the central dogma of biology?

A) DNA to RNA to protein
B) RNA to DNA to protein
C) protein to DNA to protein
D) protein to RNA to DNA
E) DNA to protein to carbohydrate

Question 17

The DNA template ATGCGTTA is transcribed into an RNA strand with the sequence

A) TACGCAAT.
B) UAACGCAU.
C) UACGCAAU.
D) AUGCGAAU.
E) AUGCGUUA.

Question 18

Ribose is an important component of RNA because

A) it is less stable than deoxyribose, which enables RNA to function as a short-term carrier of genetic information.
B) it is more stable than deoxyribose, which enables RNA to function as a short-term carrier of genetic information.
C) it is less stable than deoxyribose, which enables RNA to function as a long-term carrier of genetic information.
D) it is more stable than deoxyribose, which enables RNA to function as a long-term carrier of genetic information.
E) it is as stable as deoxyribose, which makes RNA and DNA functionally equivalent.

Question 19

Place the types of RNA molecules in correct size order,from smallest to largest.

A) mRNA, tRNA, rRNA
B) aRNA, bRNA, cRNA
C) tRNA, rRNA, mRNA
D) tDNA, rDNA, mDNA
E) proline, glycine, tyrosine

Question 20

During transcription

A) protein is synthesized from DNA.
B) DNA is replicated.
C) RNA is synthesized from protein.
D) RNA is synthesized from DNA.
E) protein is synthesized from amino acids.

Question 21

A mutation that adds one or two bases to a gene disrupts the

A) replicating frame.
B) intron index.
C) genetic code.
D) reading frame.
E) mutational profile.

Question 22

Ribosomal RNAs

A) are translated from DNA.
B) are synthesized by ribosomes.
C) connect codons to amino acids.
D) complex with proteins to form ribosomes.
E) are made from amino acid subunits.

Question 23

Transcription and replication are alike in that both

A) are guided by complementary base pairing.
B) are regulated by homeobox genes.
C) require DNA polymerase.
D) require a promoter and RNA polymerase.
E) are created from an ordered sequence of amino acids.

Question 24

In transcription,the promoter is

A) an enzyme that binds DNA.
B) a series of proteins that collectively bind to DNA.
C) a recognition sequence in RNA that attracts ribosomes.
D) A DNA sequence that RNA polymerase binds.
E) a type of mutation.

Question 25

The scientists who identified a set of coordinately regulated genes,called an operon,responsible for lactose metabolism in E.coli were

A)Watson and Crick.
B)Meselson and Stahl.
C)Jacob and Monod.
D)Hershey and Chase.
E)Linus and Pauling.

Question 26

Parts of an mRNA molecule that are removed before protein synthesis are called

A) interims.
B) exons.
C) exomes.
D) promoters.
E) introns.

Question 27

B is an intron between two exons,A and C.Which representation best describes how this region of mRNA will appear after it is transcribed and processed by a spliceosome?

A)A-C
B)A-B
C)B-C
D)A-B-C
E)B only

Question 28

A(n)_______ carries a specific amino acid to a ribosome,where the amino acid bonds to another.

A) mtDNA
B) rRNA
C) mRNA
D) tRNA
E) siRNA

Question 29

A benefit of alternate splicing of introns out of mRNAs is that

A) it maximizes the number of introns.
B) it increases the number of proteins that the genome encodes.
C) it lowers the risk of inherited disease.
D) it lowers the risk of infection.
E) it speeds transcription.

Question 30

In a bacterial cell,the three genes of the lactose operon are

A) expressed continuously.
B) expressed only when lactose is absent.
C) expressed when lactose synthesis is required.
D) expressed only in the presence of lactose.
E) never expressed, because they are pseudogenes.

Question 31

The human genome encodes about ___ transcription factors.

A) 12
B) 112
C) 875
D) 2,000
E) 3.2 billion

Question 32

Ribosomes begin translation of an mRNA transcript at the first

A) methionine.
B) anticodon.
C) AUG.
D) promoter.
E) tRNA.

Question 33

A codon consists of 3 consecutive

A) DNA bases.
B) amino acids.
C) tRNA bases
D) mRNA bases.
E) rRNA bases

Question 34

_______ consist of proteins and RNAs that associate,providing both a physical support and enzyme activity for protein synthesis.

A) Nucleosomes
B) Ribosomes
C) Acrosomes
D) Nuclei
E) Histones

Question 35

The enzyme that synthesizes messenger RNA from a DNA template is

A) DNA polymerase.
B) Rnase.
C) RNA polymerase.
D) reverse transcriptase.
E) ligase.

Question 36

There are __ different sequences of codons possible in the genetic code.

A) 3
B) 4
C) 16
D) 64
E) 46

Question 37

A ribozyme is

A) an RNA-protein complex that cleaves DNA.
B) an enzyme that catalyzes the assembly of ribosomes.
C) a small RNA that can catalyze a specific chemical reaction.
D) a stretch of uracils in RNA that directs splicing.
E) a short DNA molecule that acts as scissors on longer sequences of DNA.

Question 38

Which codons are synonymous?

A) CAC and CAG
B) CAC and CAU
C) ACA and AGC
D) UCC and GAC
E) CCC and AAA

Question 39

Transcription factors function in the expression of genes by

A) initiating transcription.
B) associating to initiate translation.
C) turning transcription of specific genes on or off.
D) halting the activity of RNA polymerase at the end of transcription.
E) bringing amino acids into the ribosome.

Question 40

After transcription and before translation,eukaryotic mRNA is modified by adding

A) tRNAs and amino acids.
B) amino acids and a poly-A tail.
C) a cap of modified nucleotides and a poly-A tail.
D) ribosomes and tRNAs.
E) an AUG at one end and a poly-U tail at the other.

Question 41

Part of a DNA template of sequence GTTAGTCTGTGGGCT corresponds to the amino acid sequence

A) GTTAGTCTGTGGGCT.
B) CAATCAGACACCCGA.
C) CAAUCAGACACCCGA.
D) gln-ser-asp-thr-arg.
E) val-ser-leu-trp-ala.

Question 42

_______ "tag" misfolded proteins so that they can be refolded or sent to proteasomes.

A) Chaperones
B) Folding catalysts
C) Signal sequences
D) Proteosomes
E) Ubiquitin molecules

Question 43

The large ribosomal subunit joins the initiation complex during _______ of translation.

A) association
B) initiation
C) elongation
D) termination
E) transference

Question 44

Diseases that are caused by protein misfolding include

A) tuberculosis, malaria, and AIDS.
B) river blindness, leprosy, and African sleeping sickness.
C) cystic fibrosis, Huntington disease, and sickle cell disease.
D) acne, restless legs syndrome, and insomnia.
E) cancer, pulmonary embolism, and hypertension.

Question 45

A signal sequence

A) directs RNA nucleotides to a particular gene.
B) attracts tRNAs to an mRNA.
C) is the first part of a protein's amino acid sequence that helps to direct it to a certain part of the cell.
D) is a coding codon that mutates into a stop codon.
E) is part of proteins that are synthesized on free ribosomes.

Question 46

The linear order of amino acids in a polypeptide is the _______ structure of a protein.

A) primary
B) secondary
C) tertiary
D) quaternary
E) chaperone

Question 47

A mutation that changes one particular amino acid into another can affect the functioning of other amino acids farther away in the primary sequence due to

A) the presence of prions.
B) protein folding.
C) the fact that the mutation functions only part of the time.
D) jumping genes.
E) the tendency for further mutations to occur.

Question 48

The genetic code is

A) triplet, overlapping, and not universal.
B) triplet, non-overlapping, and universal.
C) quarternary, overlapping, and non-universal.
D) doublet, non-overlapping, and with an inconsistent reading frame.
E) singular, non-overlapping, and universal.

Question 49

A sequence of DNA could have ____ possible reading frame(s).

A) one
B) two
C) three
D) four
E) an infinite number of

Question 50

A prion is a(n)

A) very small virus.
B) a virus built only of protein.
C) a glycoprotein that has multiple conformations and may be infectious.
D) a subatomic particle, along with a neutron and an electron.
E) infectious agent that causes AIDS.

Question 51

_______ proteins stabilize partially folded parts of proteins in their correct form.

A) Chaperone
B) Origami
C) Signal sequences
D) Proteosomes
E) Ubiquitin

Question 52

___ tRNAs are required to translate the DNA template sequence GTTAGTCTGTGGGCT into amino acids.

A) Two
B) Three
C) Four
D) Twenty
E) Sixty-four

Question 53

If part of a DNA template is the sequence GTTAGTCTGTGGGCT,then the DNA coding strand has the sequence

A) GTTAGTCTGTGGGCT.
B) CAATCAGACACCCGA.
C) CAAUCAGACACCCGA.
D) gln-ser-asp-thr-arg.
E) val-ser-leu-trp-ala.

Question 54

Which codon halts ribosomes?

A) UAG
B) AUG
C) UUU
D) ATG
E) methionine (met)

Question 55

The genetic code was deciphered

A) in the year 2000, following several years of the human genome project.
B) in the 1980s, as many Mendelian diseases had their genes identified.
C) in the 1960s.
D) in the 1950s.
E) within the past year, and hasn't been finished yet.

Question 56

_______ bonds form between amino acids during elongation.

A) Phosphodiester
B) Disulfide
C) Peptide
D) Hydrogen
E) Glycine

Question 57

If part of a DNA template is the sequence GTTAGTCTGTGGGCT,then the mRNA transcribed from it is

A) GTTAGTCTGTGGGCT.
B) CAATCAGACACCCGA.
C) CAAUCAGACACCCGA.
D) gln-ser-asp-thr-arg.
E) val-ser-leu-trp-ala.

Question 58

The sequences UUUUUUUUU .....,AAAAAAAAA......,and CCCCCCCCC.....,were the first to be analyzed to crack the genetic code because

A) they were the simplest to synthesize.
B) they would encode all types of amino acids.
C) they would encode only one type of nucleotide.
D) they would encode only one type of amino acid.
E) they could be mixed up to encode all amino acids.