Conservation of amino acid sequence among distantly related groups of organisms is
suggestive of an important function of that sequence.
Restriction endonucleases typically recognize palindromic DNA sequences and often
generate “sticky ends” or single-stranded DNA overhangs at cut sites.
Inheritance of the green and white patches phenotype in Mirabilis jalapa (four o’clocks)
is an example of maternal influence.
Lysogeny is a process that occurs during transformation and conjugation.
Natural selection occurs when there is nonrandom elimination of genotypes from a
population due to differences in viability or reproductive success.
Genomic imprinting occurs when one allele converts another.
In Drosophila, maternal-effect genes are influential in determining the
anterior-posterior organization of the developing embryo.
Assume that a species has a diploid chromosome number of 24. The term applied to an
individual with 36 chromosomes would be triploid.
Regulation of RNA transport through the nuclear membrane is as common in
prokaryotes as in eukaryotes.
Regarding the lactose utilization system in E. coli, a gratuitous inducer is a molecule
that is chemically analogous to lactose and induces the operon, but is not a substrate for
the enzymes of the lac operon.
Assuming complete dominance, a 3:1 phenotypic ratio is expected from a monohybrid
sib or self-cross.
DNA replicates conservatively, which means that one of the two daughter double
helices is “old” and the other is “new.”
A transgenic mouse model now exists for Huntington disease in humans.
The nonfunctional form of a gene is called a wild-type allele.
Each human contains an identical set of VNTRs.
In ligase-deficient strains of E. coli, DNA and chromosomal replication are unaltered
because ligase is not involved in DNA replication.
The shorter the wavelength of a radiation source, the greater its likelihood of causing
damage.
Attenuation involves the termination of mRNA synthesis.
A restriction fragment is generated by the action of a restriction enzyme (endonuclease).
In situ hybridization allows one to “visualize” the location of labeled RNA or DNA in a
tissue or cell.
Mitochondrial mutations are passed equally to offspring by both males and females.
The term aneuploidy is synonymous with the term segmental deletion.
In general, DNA replicates semiconservatively and bidirectionally.
Multigene families are characterized by clusters of tandemly arranged unique
pseudogenes organized as operons.
A characteristic of aging cells is that their telomeres become shorter.
Assume that a species has a diploid chromosome number of 24. The term applied to an
individual with 25 chromosomes would be triploid.
In the Meselson and Stahl (1958) experiment, bean plants (Vicia faba) were
radioactively labeled so that autoradiographs could be made of chromosomes.
In general, one could say that fewer levels of regulation are possible in prokaryotes than
in eukaryotes.
R plasmids often contain genes for antibody production.
Pyrimidine dimers are typically caused by the mutagen 2-aminopurine.
IS (insertion sequences) elements are stable DNA occupants of prokaryotic genomes
that are not found among eukaryotes.
DNA has no sulfur, and proteins have no phosphorus.
In a typical PCR, primers are used to cleave specific regions of the DNA template.
Drosophila and Arabidopsis use different sets of nonhomologous master regulatory
genes to establish the body axis and specify the identity of structures along such an
axis.
Under a system of positive control, transcription does not occur unless a regulator
molecule directly stimulates RNA production.
Linkage (viewed from results of typical crosses) always occurs when two loci are on
the same chromosome.
One of the earliest steps in the RNAi pathway involves the association of siRNA or
miRNA molecules with an enzyme complex composed mainly of reverse transcriptase.
There are several checkpoints in the mitotic cell cycle. All occur in the S phase.
The CAAT (CAAT box) sequence appears to be critical to the ability of many
eukaryotic promoters to facilitate transcription.
One result of X-linkage is a crisscross pattern of inheritance in which sons express
recessive genes of their fathers and daughters express recessive genes of their mothers.
In the fruit fly, Drosophila melanogaster, a spineless (no wing bristles) female fly is
mated to a male that is claret (dark eyes) and hairless (no thoracic bristles).
Phenotypically wild-type F1 female progeny were mated to fully homozygous (mutant)
males, and the following progeny (1000 total) were observed:
a) Which gene is in the middle?
b) With respect to the three genes mentioned in the problem, what are the genotypes of
the homozygous parents used in making the phenotypically wild-type F1 heterozygote?
c) What are the map distances between the three genes? A correct formula with the
values “plugged in” for each distance will be sufficient.
d) What is the coefficient of coincidence? A correct formula with the values “plugged
in” will be sufficient.
Proteomics is the ________.
A) process of defining the complete set of proteins encoded by a genome
B) harvesting of proteins from a cell to determine their economic value
C) manipulation of amino acid sequences in proteins to alter their function
D) changing of the terminal sequences of proteins to alter their function
E) rational design of drugs based on protein structure
During replication, primase adds a DNA primer to RNA.
All insertion sequences (IS elements) contain two structural elements that are essential
for their movement. What are these two elements?
A) transposase and inverted terminal repeats
B) integrase and pseudogenes
C) integrase and oncogenes
D) proto-oncogenes and oncogenes
E) transposase and oncogenes
When examining the genetic code, it is apparent that ________.
A) there can be more than one amino acid for a particular codon
B) AUG is a terminating codon
C) there can be more than one codon for a particular amino acid
D) the code is ambiguous in that the same codon can code for two or more amino acids
E) there are 44 stop codons because there are only 20 amino acids
Assume that in a series of experiments, plants with round seeds were crossed with
plants with wrinkled seeds and the following offspring were obtained: 220 round and
180 wrinkled.
a) What is the most probable genotype of each parent?
b) What genotypic and phenotypic ratios are expected?
c) Based on the information provided in part (b), what are the expected (theoretical)
numbers of progeny (400 total) of each phenotypic class?
In small isolated populations, gene frequencies can fluctuate considerably. The term
that applies to this circumstance is ________.
A) genetic isolation
B) allelic separation
C) natural selection
D) stabilizing selection
E) genetic drift
Is the accompanying figure DNA or RNA? ________ Is the arrow closest to the 5″ or 3″
end? ________ Spleen diesterase is an enzyme that breaks the covalent bond that
connects the phosphate to the 5″ carbon. Assume that the dinucleotide is digested with
spleen diesterase. To which base and to which carbon on the sugar is the phosphate now
attached, A or T?
A) DNA; 3″ end; T, 5″
B) RNA; 3″ end; A, 3″
C) DNA; 5″ end; A, 5″
D) DNA; 3″ end; A, 3″
E) RNA; 3″ end; T, 3″
The primary structure of a protein is determined by ________.
A) the sequence of amino acids
B) hydrogen bonds formed between the components of the peptide linkage
C) a series of helical domains
D) pleated sheets
E) covalent bonds formed between fibroin residues
Who, along with Alfred Wallace, formulated the theory of natural selection?
A) Gregor Mendel
B) William Harvey
C) Louis Pasteur
D) Charles Darwin
E) James Watson
Recently, a gene located on chromosome 3 in humans, FHIT, has been shown to be
associated with the significant human malady known as ________.
A) cancer
B) Huntington disease
C) “mad-cow” disease
D) Klinefelter syndrome
E) XYY/XY mosaicism
In a healthy female, how many secondary oocytes would be expected to form from 100
primary oocytes? How many first polar bodies would be expected from 100 primary
oocytes?
A) 200; 50
B) 100; 50
C) 200; 300
D) 100; 100
E) 50; 50
A condition in which one gene pair masks the expression of a nonallelic gene pair is
called ________.
A) codominance
B) epistasis
C) dominance
D) recessiveness
E) additive alleles
Which types of phenotypic ratios are likely to occur in crosses when dealing with a
single gene pair for which all the genotypic combinations are of equal viability?
A) 9:3:3:1, 27:9:9:9:3:3:3:1
B) 1:2:1, 3:1
C) 1:4:6:4:1, 1:1:1:1
D) 12:3:1, 9:7
E) 2:3, 1:2
What is the name of the membranous structure that compartmentalizes the cytoplasm of
eukaryotic organisms?
A) ribosome
B) mitochondria
C) cytosol
D) endoplasmic reticulum
E) nucleoid
In human chromosomes, satellite DNA sequences of about 170 base pairs in length are
present in tandem arrays of up to 1 million base pairs. Found mainly in centromere
regions, these DNA sequences are called ________.
A) telomeres
B) primers
C) alphoid families
D) euchromatic regions
E) telomere-associated sequences
A base at the first position of an anticodon on the tRNA would pair with a base at the
________ position of the mRNA.
G and C are present in both DNA and RNA.
The basic structure of a nucleotide includes ________.
A) amino acids
B) tryptophan and leucine
C) base, sugar, and phosphate
D) mRNA, rRNA, and tRNA
E) phosphorus and sulfur
The classic Hershey and Chase (1952) experiment that offered evidence in support of
DNA being the genetic material in bacteriophages made use of which of the following
labeled component(s)?
A) phosphorus and sulfur
B) nitrogen and oxygen
C) tritium
D) hydrogen
E) None of the answers listed are correct.
Eukaryotic chromosomes contain two general domains that relate to the degree of
condensation. These two regions are ________.
A) called heterochromatin and euchromatin
B) uniform in the genetic information they contain
C) separated by large stretches of repetitive DNA
D) each void of typical protein-coding sequences of DNA
E) void of introns
The β chain of adult hemoglobin is composed of 146 amino acids of a known sequence.
In comparing the normal β chain with the β chain in sickle cell hemoglobin, what
alteration is one likely to find?
A) valine instead of glutamic acid in the sixth position
B) glutamic acid replacing valine in the first position
C) extensive amino acid substitutions
D) trinucleotide repeats
E) frameshift substitutions
In an analysis of the nucleotide composition of double-stranded DNA to see which
bases are equivalent in concentration, which of the following would be true?
A) A = C
B) A = G and C = T
C) A + C = G + T
D) A + T = G + C
E) A = G and C = T and A + C = G + T are both true.
With which of the following would hemizygosity most likely be associated?
A) codominance
B) incomplete dominance
C) trihybrid crosses
D) X-linked inheritance
E) sex-limited inheritance
Name three forms of recombination in bacteria.
Max Delbrck presented the first evidence that bacteria are capable of spontaneous
mutation. What is the name of the test that Delbrck used to demonstrate this
phenomenon?
A) fluctuation test
B) logarithmic test
C) lag test
D) prototrophic test
E) auxotrophic test
Each of the following terms refers to the replication of chromosomes. Describe the role
(relationship) of each in (to) chromosome replication.
(a) Okazaki fragment
(b) Lagging strand
(c) Bidirectional
In what way do upstream activator sequences (UASs), regulatory sequences in yeast,
differ from enhancers and silencers?
A) UASs function only downstream.
B) UASs function only upstream.
C) Enhancers function only downstream.
D) UASs function in the middle of transcription units.
E) UASs can function only in the 5″-3″ direction.
Characteristics exhibited by continuously varying traits include ________.
A) sex-linked genes only
B) autosomal genes only
C) quantification by measuring, weighing, counting, etc.
D) a 9:3:3:1 ratio
E) 3:1 and 1:1 ratios
What two important domains within a riboswitch involve the ligand-binding site?
A) aptamer and expression platform
B) A site and B site
C) B site and C site
D) alpha and beta
E) conformation and anticonformation
In the lac operon, the product of structural gene lacZ is capable of ________.
A) nonautonomous replication
B) forming lactose from two glucose molecules
C) replacing hexokinase in the early steps of glycolysis
D) splitting the -linkage of lactose
E) forming ATP from pyruvate
If the GC content of a DNA molecule is 60%, what are the molar percentages of the
four bases
(G, C, T, A)?
Following are four processes common to most cloning experiments:
a) transforming bacteria
b) plating bacteria on selective medium
c) cutting DNA with restriction endonucleases
d) ligating DNA fragments
Place components of this list in the order in which they would most likely occur during
a cloning experiment.
What term is used to express the idea that several genes exert influence over the same
characteristic?
A) coextension
B) co-adhesion
C) terminal interaction
D) gene interaction
E) transformation
Two modular elements that appear as consensus sequences upstream from RNA
polymerase II transcription start sites are ________.
A) microsatellites and transposons
B) rDNA and nucleolar organizers
C) TATA and CAAT
D) TTAA and CCTT
E) enhancers and telomeres
What is meant by the term low gene density? Give an example of an organism with low
gene density.
In a population of 10,000 individuals, where 3600 are MM, 1600 are NN, and 4800 are
MN, what are the frequencies of the M alleles and the N alleles?
Early in the 1900s, Sir Archibald Garrod studied a number of metabolic defects in
humans. One particular disorder involved the inability to metabolize homogentisic acid.
What is the name of this disorder?
The house fly, Musca domestica, has a haploid chromosome number of 6. How many
chromatids should be present in a diploid, somatic, metaphase cell?
What is meant by the term heritability? Describe the components of heritability and
provide a brief explanation of each. Of what interest is heritability to animal and plant
breeders?
A constitutive mutation in the lac operon may be of several types. Name two types of
constitutive mutations.
When a trait is polygenic, but distinguished from continuous and meristic traits by
having a small number of discrete classes, it is said to be a(n) ________ trait.
What is meant by punctuation in terms of the genetic code?
Describe three characteristics of enhancers and silencers.
Under ideal conditions, how many copies of all the sequences of the host genome
should be represented in a genomic library?
The complex of proteins that is involved in the replication of DNA is called a(n)
________.
What is meant by the term helix-turn-helix (HTH)?
What is the Ames test, and how does it work?
What formula can be used to determine the number of categories (phenotypes) possible
in the F2 results of a polygenic system?
Describe the function and general nature of promoters in eukaryotes.
Considering the types of side chains on amino acids and their relationship to protein
structure, where are the amino acids with hydrophobic side chains most likely to be
located?
When native chromatin is digested with micrococcal nuclease, what significant result
occurs?
What is the biochemical role of adenyl cyclase?
Generally, vaccines are used to stimulate the immune system by providing antigens of
potential pathogens. What is the typical composition of a vaccine?