DNA and RNA are polymers composed of ______ monomers.
A) nucleotide
B) carbohydrate
C) fatty acid
D) amino acid
A) nucleotide
The backbone of DNA consists of ______.
A) nitrogenous bases
B) a repeating sugar-nucleotide-sugar-nucleotide pattern
C) a repeating sugar-phosphate-sugar-phosphate pattern
D) paired nucleotides
C) a repeating sugar-phosphate-sugar-phosphate pattern
Thymine and cytosine differ from adenine and guanine in that
A) thymine and cytosine are single-ring structures, whereas adenine and guanine are double-ring structures.
B) thymine and cytosine are only found in DNA, whereas adenine and guanine are found i
A) thymine and cytosine are single-ring structures, whereas adenine and guanine are double-ring structures.
RNA contains the nitrogenous base ______ instead of ______, which is only found in DNA.
A) a deoxyribose sugar... a ribose sugar
B) uracil... thymine
C) uracil... guanine
D) thymine... uracil
B) uracil... thymine
If adenine makes up 20% of the bases in a DNA double helix, what percent of the bases are guanine?
A) 60%
B) 40%
C) 20%
D) 30%
D) 30%
In a DNA double helix, adenine pairs with ______ and guanine pairs with ______.
A) cytosine... thymine
B) guanine... adenine
C) thymine... cytosine
D) uracil... cytosine
C) thymine... cytosine
If one strand of a DNA double helix has the sequence GTCCAT, what is the sequence of the other strand?
A) ACTTGC
B) TGAACG
C) CAGGTA
D) CAGGUA
C) CAGGTA
Who discovered the structure of DNA?
A) Pauling
B) Watson and Crick
C) Franklin
D) Hershey and Chase
B) Watson and Crick
Evidence for the spiral nature of DNA came from ______.
A) X-ray crystallography studies
B) studies of disease-causing bacteria
C) base rule studies
D) bacteriophage studies
A) X-ray crystallography studies
What type of chemical bond joins the bases of complementary DNA strands?
A) ionic
B) covalent
C) hydrophilic
D) hydrogen
D) hydrogen
After replication, ______.
A) each new DNA double helix consists of two old strands
B) each new DNA double helix consists of one old strand and one new strand
C) each new DNA double helix consists of two new strands
D) one new DNA double helix consists of
B) each new DNA double helix consists of one old strand and one new strand
DNA replication
A) is a slow process that results in virtually no errors.
B) requires DNA polymerase and RNA polymerase.
C) is a very fast process that results in numerous errors.
D) requires the cooperation of over a dozen enzymes and other proteins.
D) requires the cooperation of over a dozen enzymes and other proteins.
The modern phrasing of Beadle and Tatum's hypothesis about relationships between genes and their products is "one gene-one ______."
A) enzyme
B) RNA
C) protein
D) polypeptide
D) polypeptide
What name is given to the collection of traits exhibited by an organism?
A) holotype
B) genotype
C) phenotype
D) morphology
C) phenotype
How many amino acids are common to all living systems?
A) 10
B) 20
C) 30
D) 100
B) 20
How many nucleotides make up a codon?
A) two
B) three
C) four
D) five
B) three
The shared genetic code of all life on Earth is evidence that ______.
A) the genetic code arose relatively late in the history of life on Earth
B) DNA replication is error-free
C) all life shares a common ancestry
D) bacterial cells arose earlier than euk
C) all life shares a common ancestry
Transcription is the ______.
A) manufacture of a strand of RNA complementary to a strand of DNA
B) manufacture of two new DNA double helices that are identical to an old DNA double helix
C) modification of a strand of RNA prior to the manufacture of a pro
A) manufacture of a strand of RNA complementary to a strand of DNA
If a strand of DNA has the sequence AAGCTC, transcription will result in a(n) ______.
A) single RNA strand with the sequence TTCGAG
B) DNA double helix with the sequence AAGCTC for one strand and TTCGAG for the complementary strand
C) single RNA strand wi
C) single RNA strand with the sequence UUCGAG
Which of the following enzymes is responsible for RNA synthesis?
A) RNase
B) RNA helicase
C) RNA ligase
D) RNA polymerase
D) RNA polymerase
The region of DNA where RNA synthesis begins is the ______.
A) start codon
B) promoter
C) initiator
D) processor
B) promoter
The correct sequence of events occurring during transcription is ______.
A) splicing, capping, tailing
B) initiation, elongation, termination
C) tailing, capping, splicing
D) elongation, initiation, termination
B) initiation, elongation, termination
The absence of a terminator in transcription will result in ______.
A) the creation of a virus
B) a strand of mRNA that lacks its cap and tail
C) the production of a longer RNA molecule
D) the production of a shorter RNA molecule
C) the production of a longer RNA molecule
What protects mRNA from attack by cellular enzymes?
A) RNA splicing
B) the removal of exons
C) the lack of RNA-digesting enzymes in the cytoplasm
D) a cap and tail
D) a cap and tail
The expressed (coding) regions of eukaryotic genes are called ______.
A) caps
B) promoters
C) exons
D) introns
C) exons
Translation converts the information stored in ______ to ______.
A) DNA... RNA
B) RNA... a polypeptide
C) DNA... a polypeptide
D) RNA... DNA
B) RNA... a polypeptide
The RNA that is translated into a polypeptide is ______ RNA.
A) nuclear
B) ribosomal
C) transfer
D) messenger
D) messenger
The DNA codon AGT codes for an amino acid carried by a tRNA with the anticodon ______.
A) TCU
B) AGU
C) TCA
D) AGT
B) AGU
Where is translation accomplished?
A) lysosomes
B) smooth endoplasmic reticulum
C) ribosomes
D) nucleoli
C) ribosomes
During translation, what is the correct order of events that occur as an amino acid is added?
A) codon recognition, peptide bond formation, translocation
B) translocation, codon recognition, termination
C) initiation, codon recognition, termination
D) pep
A) codon recognition, peptide bond formation, translocation
Peptide bonds form between ________.
A) amino acids
B) an mRNA codon and a tRNA anticodon
C) a tRNA and the amino acid it is carrying
D) an mRNA transcript and the small ribosomal subunit
A) amino acids
A mutation within a gene that will insert a premature stop codon in mRNA would ______.
A) result in a polypeptide that is one amino acid shorter than the one produced prior to the mutation
B) result in a shortened polypeptide chain
C) change the location
B) result in a shortened polypeptide chain
What is the smallest number of nucleotides that must be added or subtracted to change the triplet grouping of the genetic message?
A) one
B) two
C) three
D) four
A) one
What is the ultimate source of all diversity?
A) natural selection
B) sexual recombination
C) meiosis
D) mutation
D) mutation
Mad cow disease is caused by
A) a retrovirus similar to HIV.
B) an enveloped virus.
C) small circular RNA molecules called viroids.
D) infectious proteins called prions.
D) infectious proteins called prions
How can bacteriophage DNA be spread from cell to cell without causing cell death?
A) by altering the way a cell splices its RNA
B) via a lytic cycle
C) via a lysogenic cycle
D) by altering its DNA
C) via a lysogenic cycle
Plant viruses ______.
A) often use RNA, rather than DNA, as their genetic material
B) benefit plants, rather than causing disease
C) cause diseases that can be easily cured
D) do not exist-viruses only attack animals
A) often use RNA, rather than DNA, as their genetic material
A(n) ______ is to bacteria as a ______ is to animal cells.
A) retrovirus... virus
B) phage... prophage
C) prophage... provirus
D) RNA virus... DNA virus
C) prophage...... provirus
HIV (human immunodeficiency virus) must use its own ______ to reproduce.
A) DNA polymerase
B) reverse transcriptase
C) RNA polymerase
D) tRNA
B) reverse transcriptase
Once viruses are detected, the number of viruses increases rapidly. This is because ______.
A) lysogeny produces large numbers of bacteriophages
B) DNA viruses reproduce more rapidly than RNA viruses
C) the host cell speeds the release process
D) the viru
D) the viruses lyse the hosts to release mature viruses all at once
The mutation would be most harmful to the cells if it resulted in ______.
A) a single nucleotide insertion near the start of the coding sequence
B) a single nucleotide deletion near the end of the coding sequence
C) a single nucleotide in the middle of an
A) a single nucleotide insertion near the start of the coding sequence
42) The figure below shows the flow of genetic information in a eukaryotic cell. The transfer of information from DNA into an RNA molecule is known as ______.
A) DNA replication
B) transcription
C) polypeptide
D) translation
B) transcription
43) Examine the genetic code table, shown below. The codon AGC codes for the amino acid ______.
A) serine
B) arginine
C) threonine
D) alanine
A) serine
44) Consider the following figure. It indicates that a single amino acid substitution ______.
A) always involves adenine and uracil
B) may alter a protein so that it no longer functions properly
C) is a silent mutation
D) causes a nonsense mutation
B) may alter a protein so that it no longer functions properly
45) If you were asked to study the pattern of bacterial growth (increase in numbers over time) during an infection, you would find that numbers of bacteria increase exponentially up to a certain point. Assume that you have been asked to interpret the grow
B) although the virus has infected the host, it takes time to complete the lytic cycle
While working with cultured mouse cells, a researcher unknowingly treated the cells with a mutagen that causes the deletion or insertion of individual nucleotides in DNA. Subsequently, she isolated and cultured a single cell from this group. She noticed t
B) one that changed the triplet grouping of the genetic message