If a typical G1 nucleus contains 2C (two complements) of DNA, a gamete that is
haploid (n) contains 1C of DNA.
A DNA microarray (also called a DNA chip) can be used to ________.
A) mutate genes of interest
B) isolate genes from eukaryotic cell nuclei
C) assay protein output from a genomic database
D) trap genes that are both active and inactive
E) scan a population of nucleic acids for abundance and mutations
What significant genetic function occurs in the S phase of the cell cycle?
A) cytokinesis
B) karyokinesis
C) DNA synthesis
D) chromosome condensation
E) centromere division
If a typical somatic cell has 64 chromosomes, how many chromosomes are expected in
each gamete of that organism?
A) 8
B) 16
C) 32
D) 64
E) 128
Huntington disease (HD) is a well-studied, autosomal dominant disorder that affects the
nervous system. Symptoms usually appear after age 40, and victims usually die within
10 to 15 years after onset of the disease. It appears that at least in some cases of HD,
“stutter” mutations occur. Such mutations are characterized by ________.
A) uncontrolled verbal capacity of patients
B) extra trinucleotide repeats within the HD gene
C) RNA polymerase imperfections leading to altered DNAs
D) repeated DNA polymerases generating too many coding symbols
E) links between monoamine oxidase A (MAOA) and hexokinase
In many species, there are two representatives of each chromosome. In such species, the
characteristic number of chromosomes is called the ________ number. It is usually
symbolized as ________.
A) haploid; n
B) haploid; 2n
C) diploid; 2n
D) diploid; n
E) None of the answers listed are correct.
Driver mutations provide a growth advantage to a tumor cell. Which type of mutation is
known to accumulate in cancer cells but has no direct contribution to the cancer
phenotype?
A) alteration mutations
B) passenger mutations
C) carrier mutations
D) indirect mutations
E) insignificant mutations
The E. coli chromosome is circular and double-stranded DNA.
(a) In a three-point mapping experiment, what three general classes of offspring are
expected (assuming crossovers occur)? (b) How many different genotypic classes are
expected?
One of the primary reasons for generating a large number of clones in a eukaryotic
genomic library is that ________.
A) each cosmid replicates in coordination with the host chromosome
B) lysogenic phages continue to integrate their DNA into the host chromosome, thus
reducing the number of desired recombinant clones
C) each vector can take up only a relatively small fraction of the eukaryotic DNA
D) each ligation product is sequence specific
E) the host range of the vector is limited
One form of hemophilia is caused by a sex-linked recessive gene. Assume that a man
with hemophilia marries a phenotypically normal woman whose father had hemophilia.
What is the probability that they will have a daughter with hemophilia? (Note: In this
problem, you must include the probability of having a daughter in your computation of
the final probability.)
A) 1/16
B) 1/8
C) 1/4
D) 1/2
E) 3/4
What is the term given to the theory that put forth the idea that living organisms could
arise by incubating nonliving components?
A) spontaneous generation
B) natural selection
C) evolution
D) preformation
E) collective combination
The main purpose of a probe is its insertion in plasmid DNA.
DNA methylation may be a significant mode of genetic regulation in eukaryotes.
Methylation refers to ________.
A) altering RNA polymerase activity by DNA modifications
B) changes in DNA-DNA hydrogen binding
C) altering translational activity especially of highly methylated tRNAs
D) alteration of DNA polymerase activity by addition of methyl groups to glycine
E) residues
F) addition of methyl groups to the cytosine of CG doublets
During interphase of the cell cycle, ________.
A) DNA recombines
B) sister chromatids move to opposite poles
C) the nuclear membrane disappears
D) RNA replicates
E) DNA content essentially doubles
Direction of shell coiling in the snail Lymnaea peregra is conditioned by a form of
extrachromosomal inheritance known as ________.
A) sex-linked inheritance
B) heteroplasmy
C) maternal effect
D) independent assortment
E) epistasis
What is the expression pattern of dominant-negative mutations in petite strains of
yeast?
A) Expression of wild-type mitochondria is enhanced.
B) Expression of mutant mitochondria resembles expression of wild-type mitochondria.
C) Mitochondria show enhanced capacity of oxidative phosphorylation.
D) The function of wild-type mitochondria is suppressed.
E) Mitochondrial membranes become hyperpolarized.
In E. coli, the genetic material is composed of ________.
A) circular, double-stranded DNA
B) linear, double-stranded DNA
C) RNA and protein
D) circular, double-stranded RNA
E) polypeptide chains
Typically, when one wishes to represent a gene, the symbol used is _________.
A) in italics
B) in all lowercase letters
C) in all upper case letters
D) in bold print
E) underlined
Which terms accurately reflect the nature of replication of the chromosome in E. coli?
A) bidirectional and fixed point of initiation
B) unidirectional and reciprocal
C) unidirectional and fixed point of initiation
D) multirepliconic and telomeric
E) bidirectional and multirepliconic
Consider the structure of double-stranded DNA. When DNA is placed into distilled
water, it denatures; however, by adding NaCl, the DNA renatures. Why?
It has been recently determined that the gene for Duchenne muscular dystrophy (DMD)
is more than 2000 kb (kilobases) in length; however, the mRNA produced by this gene
is only about 14 kb long. What is a likely cause of this discrepancy?
A) The exons have been spliced out during mRNA processing.
B) The DNA represents a double-stranded structure, whereas the RNA is
single-stranded.
C) There are more amino acids coded for by the DNA than by the mRNA.
D) The introns have been spliced out during mRNA processing.
E) When the mRNA is produced, it is highly folded and therefore less long.
Because of the imprecision of molecular joining, recombination between LV and J
regions shows considerable variation. Which additional circumstance contributes to this
variation?
A) transmutation
B) hypermutation
C) transfection
D) conjugation
E) transduction
For an individual with the XXY chromosomal composition, the expected number of
Barr bodies in interphase cells is ________.
A) variable
B) one
C) two
D) three
E) zero
Which cluster of terms accurately reflects the nature of DNA replication in
prokaryotes?
A) fixed point of initiation, bidirectional, conservative
B) fixed point of initiation, unidirectional, conservative
C) random point of initiation, bidirectional, semiconservative
D) fixed point of initiation, bidirectional, semiconservative
E) random point of initiation, unidirectional, semiconservative
Trisomy 21, or Down syndrome, occurs when there is a normal diploid chromosomal
complement of 46 chromosomes plus one (extra) chromosome #21. Such individuals
therefore have 47 chromosomes. Assume that a mating occurs between a female with
Down syndrome and a normal 46-chromosome male. What proportion of the offspring
would be expected to have Down syndrome? Justify your answer.
What is the typical gene density per kilobase in prokaryotes?
A) 426,000
B) 3000
C) 1200
D) 1
E) 12
A number of mechanisms operate to maintain genetic diversity in a population. Why is
such diversity favored?
A) Homozygosity is an evolutionary advantage.
B) Diversity leads to inbreeding advantages.
C) Genetic diversity may better adapt a population to inevitable changes in the
environment.
D) Greater genetic diversity increases the chances of haploidy.
E) Genetic diversity helps populations avoid diploidy.
Typical ratios resulting from epistatic interactions in dihybrid crosses would be
________.
A) 9:3:3:1, 1:2:1
B) 1:1:1:1, 1:4:6:4:1
C) 9:3:4, 9:7
D) 1:2:2:4:1:2:1:2:1, 1:2:1
E) 3:1, 1:1
Which of the following terms accurately describes the replication of DNA in vivo?
A) conservative
B) dispersive
C) semidiscontinuous
D) nonlinear
E) nonreciprocal
How many haploid sets of chromosomes are present in a diploid individual cell with a
chromosome number of 46? 32?
What experimental observation demonstrated that genes are involved in the integration
of foreign DNA into the bacterial chromosome?
List at least two statistical terms commonly used in the analysis of quantitative traits.
Give the sex-chromosome constitution (X and Y chromosomes) and possible genotypes
of offspring resulting from a cross between a white-eyed female (Xw XwY) and a
wild-type male (normal chromosome complement) in Drosophila melanogaster.
Include all zygotic combinations whether viable or inviable.
What particular karyotype was at one time considered to be related to criminal
predisposition?
Apurinic sites (AP sites) involve a spontaneous loss of a(n) ________ in an intact
double-helix DNA molecule.
In the evolutionary sense, what is meant by the term molecular clock?
Design an experiment that would allow you to determine if a particular nucleus in a
Drosophila embryo is capable of directing development of an entire new fly.
Why is cyclic AMP considered important in behavioral studies?
Which functions earlier in development: maternal-effect genes or zygotic genes?
List at least three statistical values often used to represent a sample.
A particular variant of the lambda bacteriophage has a DNA double-stranded genome of
51,365 base pairs. How long would this DNA be?
Assume that you are studying a trait determined by a number of polygenes. If there are
seven phenotypic categories, how many genes are probably involved?
Under what conditions does one expect a 9:3:3:1 ratio?
Provide an example of gene redundancy that occurs in both eukaryotes and prokaryotes.
Bacteria that are in a particular physiological state to become transformed are called
________.