Micro Bio Chp 7 Exam 3
All of the following are associated with nucleic acid structure EXCEPT
ionic bonds
Which of the following is found at the 5" end of a DNA strand?
a phosphate group
The bacterial chromosome is
both circular and found in a nucleoid
Which of the following types of plasmids allows a bacterial cell to kill its competitors?
bacterioncin factors
Which of the following is NOT involved in the packaging of eukaryotic chromosomes?
Okazaki fragments
Which of the following statements is true of bacterial plasmids?
they are small circular DNA molecules that can replicate autonomously
The process indicated by the arrow in Fig 7.1 represents?
lagging strand synthesis
Which of the the following statements concerning transcription in bacteria is FALSE?
The same RNA polymerase transcribes primer RNA, mRNA, tRNA, and rRNA.
Which of the following is involved in translation?
mRNA, rRNA, and tRNA are all involved
Which of the following is a characteristic shared by DNA and RNA polymerase?
direction of polymerization
Typical eukaryotic genomes are composed of ______ DNA molecules.
multiple linear
A codon is a particular combination of three nucleotides. Therefore, there are _____ possible combinations of the nucleotides A, C, G, and T.
64
The AUG codon functions in coding for the amino acid methionine and as a
start signal
Which of the following regulatory RNAs alter translation in response to environmental conditions?
riboswitches
During elongation a charged tRNA first enters the ribosomal ______ site and then moves into the _____ site.
A, P
A wild-type organism and a genetic variant both have a gene encoding a receptor producing a chemotactic response to metabolite A. The genetic variant has a mutation in a regulatory gene for expression of the receptor. Which of the following statements with respect to the receptor is CORRECT?
The organisms have the same receptor genotype but different phenotypes.
Semiconservative DNA replication means that
each daughter DNA molecule is composed of one original strand and one new strand
Which of the following is NOT a characteristic of Okazaki fragments?
They are longer in eukaryotic cells
DNA replication and RNA transcription have many features in common. Which of the following does NOT occur in both processes?
a requirement for a primer
Which of the following processes is involved in the "central dogma" of genetic?
transcription and translation
Inducible operons
usually require an activator to be transcribed
Which of the following are considered to be frameshift mutations?
both deletions and insertions
If the codon AAA is changed to AAG, it still codes for the amino acid lysine; this is an example of a
silent mutation
Which of the following causes mutations by creating thymine dimers?
ultraviolet light
DNA damage caused by ethidium bromide results in _______ mutations.
both insertion and deletion
Which of the following is a DNA repair enzyme activated by visible light?
DNA photolyase
The Ames test demonstrates that a chemical is
mutagenic in Salmonella
The horizontal transfer process known as transduction
involves a virus
Frederick Griffith discovered
transformation
In conjugation, F+ cells
contain an F plasmid
Another term for the palindromic sequence found at the ends of transposons is a
inverted repeat
Which of the following is characteristic of prokaryotic genomes but NOT eukaryotic genomes?
circular chromosomes
The procedure known as "replica plating" is used in
negative selection only
The DNA sequence of a portion of gene in a wild-type organisms is TTACCATATTCACCC, and the corresponding peptide sequence is Leu-Pro-Tyr-Ser-Pro. The corresponding gene fragment in phenotypic variant of the organism is TTACCATATTCACCC and the peptide sequence is Leu-Pro-Cys-Ser-Pro. This is an example of a ______ mutation type resulting in a ______ mutation effect.
base substitution; missense
Which of the following is NOT involved in the regulation of the lac operon?
an iRNA
Genetic elements known as promoters are initiation points in the process of
transcription
Codons are recognized during
translation
The events of ______ are initiated at sequences called origins.
DNA replication
The process of ________ requires the activity of DNA ligase.
DNA replication
RNA polymerase is primarily responsible for
transcription
The process of ______ requires participation of tRNA molecules.
translation
The process known as _____ is initiated with the incorporation of fMet.
translation
Transfer of random pieces of DNA mediated by phage is known as
generalized transduction
The process of _______ is described as semiconservative.
DNA replication
During _____, a new peptide bond is formed with the amino acid located in the A site.
translation
A (operon/codon/gene) is a specific sequence of nucleotides that codes for a protein or an RNA molecule.
gene
Loosely packed, transcriptionally active regions of a eukaryotic chromosome is called (euchromatin/ heterochromatin/ nucleosomes).
euchromatin
Transfer of DNA between bacterial cells by viruses is called (transformation/ transduction/ conjugation).
transduction
The phenotype of an organism is its set of (genes/ traits/ chromosomes).
traits
The enzyme responsible for separating the DNA strands during DNA replication is (topoisomerase/ primase/ helicase).
helicase
The chemical 5-bromouracil mimics the chemical structure of thymine, making it an (analog/ nucleotide/ precursor) of thymine.
analog
A protein has altered function as a result of a single amino acid substitution in the polypeptide. this change resulted from a (missense/ nonsense/ silent) mutation.
missense
Except during intitiation of translation, transfer RNA molecules carrying amino acids initially bind to the ribosome at the (P/ A/ E) site.
A
The (codon/ antidcodon/ loop) of a transfer RNA molecule is complementary to a codon in a messenger RNA molecule.
antidcodon
Acridine dyes distort the structure of DNA causing (frameshift/ missense/ nonsense) mutations in gene sequences.
frameshiftf
A (genome/ codon/ operon) is a set of prokaryotic genes that are regulated and transcribed as a unit.
operon
The (leading/ lagging/ replicating) strand is the DNA strand that is synthesized continuously during DNA replication.
leading
The (phenotype/ genome/ genotype) is the set of genes in the genome of an organism.
genotype
RNA polymerase initiates transcription by recognizing specific DNA sequences called (promoter/ origins/ operons).
promoter
While studying a bacterial strain a scientist notes a short DNA sequences between inverted repeats in present in both the chromosome and a plasmid within the cell. This sequence is most likely a (phage/ transposon/ F plasmid).
transposon