To produce recombinants in bacteria, one crossover is better than two.
Genomic anticipation refers to observations that a genetic disorder occurs at an earlier
age in successive generations, whereas genetic imprinting occurs when gene expression
varies depending on parental origin.
Chromatin assembly factors (CAFs) move along with the replication fork and assemble
new nucleosomes.
Assume that an organism has a diploid chromosome number of 14. There would be 28
chromosomes in a tetraploid.
The Human Genome Project is an international effort to construct a base sequence of
the approximately 3 billion base pairs in the haploid human genome.
Given an inheritance pattern of incomplete dominance and 81 flowers that are red
(R1R1), 18 flowers that are pink (R1R2), and 1 flower that is white (R2R2), the frequency
of the R1 allele is 0.9.
With both incomplete dominance and codominance, one expects heterozygous and
homozygous classes to be phenotypically identical.
Avery et al. (1944) determined that DNA is the genetic material in T2 bacteriophage.
During meiosis, chromosome number reduction takes place in anaphase II.
The cross GE/ge x ge/ge produces the following progeny: GE/ge 404; ge/ge 396; gE/ge
97; Ge/ge 103. From these data one can conclude that there are 20 map units between
the G and E loci.
The triplet AUG is commonly used as a start codon during translation.
One of the problems associated with the generation of transgenic plants is that the
ecological parameters of many plants are not completely understood.
Caenorhabditis elegans is extremely useful as an experimental organism because it has
relatively few cells, and, for the most part, each embryonic cell’s fate is
developmentally fixed.
Selection is the differential reproduction of genotypes, resulting from their variable
fitness.
During a PCR, heat is provided to inactivate the polymerase enzyme.
Proteins are composed of strings of nucleotides connected together by 5″-3″
phosphodiester bonds.
Pattern baldness and hen/cock feathering in fowl are examples of X-linked inheritance.
Direct-to-consumer provides an accurate assessment of physiological and behavioral
circumstances within patients that will eventually replace the need for routine visits to
the doctor.
A chromosome may contain one or two chromatids in different phases of the mitotic or
meiotic cell cycle.
Polygenes are involved in determining continuously varying or multiple-factor traits.
Hemizygosity is the term one uses to describe the state of a gene that has no allele on
the opposing chromosome.
Additive alleles are those that are epistatic over nonallelic genes that influence the same
phenotypic characteristic.
Attenuation is known to occur in the lac operon.
In recombinant DNA technology, YAC, RFLP, and λ have identical uses.
A position effect occurs when a gene’s expression is altered by virtue of a change in its
position. One might expect position effects to occur with inversions and translocations.
In humans, the male is the homogametic sex.
In Drosophila, sex is determined by the ratio of the number of X chromosomes to the
number of haploid sets of autosomes.
The genome of humans is remarkably stable, so much so that there are no cancers
known to result from genomic instability.
Heritability is a measure of the degree to which the phenotypic variation of a given trait
is due to genetic factors.
The symptoms of Huntington disease usually appear in the third to fifth decade of life
in humans.
Dosage compensation is accomplished in humans by inactivation of the Y chromosome.
A 1:1 phenotypic ratio is expected from a monohybrid testcross with complete
dominance.
The genomic organization of all living creatures is identical.
Under a system of negative control, genetic expression occurs unless such expression is
shut off by some form of regulator.
Chromatin of eukaryotes is organized into repeating interactions with protein octamers
called nucleosomes. Nucleosomes are composed of which class of molecules?
A) histones
B) glycoproteins
C) lipids
D) H1 histones
E) nonhistone chromosomal proteins
The clearing made by bacteriophages in a “lawn” of bacteria on an agar plate is called a
________.
A) clear zone
B) lysogenic zone
C) prophage
D) plaque
E) host range
In Drosophila, sex is determined by a balance between the number of haploid sets of
autosomes and the number of ________.
A) telomeres
B) centromeres
C) X chromosomes
D) Y chromosomes
E) nucleolar organizers
Which term refers to the regulatory events that establish a specific pattern of gene
activity and developmental fate for a given cell?
A) lysogen
B) differentiation
C) determination
D) gradient regulated
E) attenuation
Numerous scientists around the world have proposed to sequence 10,000 vertebrate
genomes in five years. What is the name of this plan?
A) Genome 10K
B) Bigger Than Life Plan
C) 10K or Bust
D) Vertebrate Beginnings
E) Vertebrate Enlightenment
When considering the initiation of transcription, one often finds consensus sequences
located in the region of the DNA where RNA polymerase(s) binds. Which of the
following is a common consensus sequence?
A) TATA
B) GGTTC
C) TTTTAAAA
D) any trinucleotide repeat
E) satellite DNAs
A retrovirus uses reverse transcriptase to make a DNA copy of RNA.
The following table presents the effect of different media on the growth response of
tryptophan mutations in Salmonella typhimurium (+ = growth, – = no growth).
(a) Construct the biochemical pathway for the compounds IGP, AA, IN, and TRY based
on these data.
(b) Place strains of bacteria (mutations) in the appropriate steps in the pathway.
(c) In bacteria it is often possible to make partial diploid strains. Assume that a diploid
strain was made containing the complete genomes of the trp-2 and trp-1 strains. Would
this diploid strain be able to grow on the unsupplemented medium? Explain your
answer.
Name two forms of recombination in bacteria.
A) lytic and lysogenic
B) auxotrophic and prototrophic
C) conjugation and transduction
D) mixed and generalized
E) insertion and replication
Myrmecia pilosula actually consists of several virtually identical, closely related
species, with females having chromosome numbers of 18, 20, 32, 48, 60, 62, and 64.
Assume one crossed a female of species (A) with 32 chromosomes and a male of
species (B) with 9 chromosomes (males are haploid, and each gamete contains the n
complement). How many chromosomes would one expect in the body (somatic) cells of
the female offspring?
A) 4.5
B) 9
C) 25
D) 32
E) 41
Bioinformatics is a discipline involved in the development of both hardware and
software for processing, storing, and retrieving nucleotide and protein data.
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 their first son will have hemophilia?
A) 1/16
B) 1/8
C) 1/4
D) 1/2
E) 3/4
Assume that the molar percentage of thymine in a double-stranded DNA is 20. What are
the percentages of the four bases (G, C, T, A)? If the DNA is single-stranded, would you
change your answer?
Direction of shell coiling in Lymnaea peregra is strongly and most directly influenced
by_______.
A) the genotype of the mother
B) the genotype of the father
C) the phenotype of the mother
D) the phenotype of the father
E) the genotype of the embryo itself
Trisomy 21, or Down syndrome, occurs when there is a normal diploid chromosomal
complement but one (extra) chromosome 21. While there is reduced fertility in both
sexes, females have higher fertility than males. Van Dyke et al. (1995; Down Syndrome
Research and Practice 3(2):6569) summarize data involving children born of Down
syndrome individuals. Given the fact that conceptuses with 48 chromosomes (four #21
chromosomes) are not likely to survive early development, what percentage of
surviving offspring would be expected to have Down syndrome if both parents have
Down syndrome?
A) One-third of the surviving offspring would be expected to have Down syndrome.
B) All the children would be expected to have Down syndrome.
C) None of the surviving offspring would be expected to have Down syndrome.
D) Two-thirds of the surviving offspring would be expected to have Down syndrome.
E) One-half of the surviving offspring would be expected to have Down syndrome.
List four enzymes known to be involved in the replication of DNA in bacteria.
Which of the following two terms relate most closely to split genes?
A) 5″-cap, 3″-poly-A tail
B) introns, exons
C) elongation, termination
D) transcription, translation
E) heteroduplex, homoduplex
One explanation for organelle inheritance is that ________.
A) mitochondria and chloroplasts lack DNA and are therefore dependent on the
maternal cytoplasmic contributions
B) mitochondria and chloroplasts have DNA that is subject to mutation
C) organelles such as mitochondria are always wild type
D) chloroplasts, for example, are completely dependent on the nuclear genome for
components
E) None of the answers listed are correct.
Which of the following name two mutagens that would be classified as base analogs?
A) acridine orange and proflavine
B) ethylmethane sulfonate and ethylmethylketone peroxide
C) ultraviolet light and cosmic radiation
D) 5-bromouracil and 2-amino purine
E) hydroxyurea and peroxidase
What is the name given to the three bases in a messenger RNA that bind to the
anticodon of tRNA to specify an amino acid placement in a protein?
A) protein
B) anti-anticodon
C) cistron
D) rho
E) codon
What is the term given to a group of individuals belonging to the same species that live
in a defined geographic area that actually or potentially interbreed?
A) population
B) consanguinity
C) hybrid vigor
D) genetics
E) cytogenetics
Mutations that arise in nature, from no particular artificial agent, are called ________.
A) oblique mutations
B) induced mutations
C) spontaneous mutations
D) chromosomal aberrations
E) cosmic mutations
Albinism, lack of pigmentation in humans, results from an autosomal recessive gene
(a). Two parents with normal pigmentation have an albino child. What is the probability
that their next child will be albino?
Some vectors such as pUC18 and others of the pUC series contain a large number of
restriction enzyme sites clustered in one region. Which term is given to this
advantageous arrangement of restriction sites?
A) palindrome
B) consensus sequence
C) multiple cloning site
D) β-galactosidase
E) complementation
Name the single individual whose work in the mid-1800s contributed to our
understanding of the particulate nature of inheritance as well as the basic genetic
transmission patterns. With what organism did this person work?
A) Gregor Mendel; Pisum sativum
B) George Beadle; Neurospora
C) Thomas Hunt Morgan; Drosophila
D) Calvin Bridges; Drosophila
E) Boris Ephrussi; Ephestia
Channels between chromosomes in the interphase nucleus are called ________.
A) extrachromosomal elements
B) localized zones
C) nonlocalized zones
D) interchromosomal compartments
E) subchromosomal territories
Restriction endonucleases are especially useful if they generate “sticky” ends. What
makes an end sticky?
A) single-stranded complementary tails
B) blunt ends
C) poly-A sequences
D) 5″ cap
E) interference
The Human Genome Project, which got under way in 1990, is an international effort to
________.
A) determine the base sequence of the human genome and to identify all the genes
within
B) collect samples of cells from all parts of the world in order to preserve human
genetic diversity
C) collect plant seeds in order to reduce the impact of human activity on plant
extinction
D) clone deleterious genes from humans and study their mode of action
E) clone beneficial genes from humans for eventual use in gene therapy
Drosophila melanogaster, the fruit fly, has a 2n chromosome number of 8. Assume that
you are microscopically examining the mitotic and meiotic cells of this organism. You
note that in the female, two chromosomal pairs are metacentric and that two pairs are
acrocentric.
a) Draw the chromosomal configurations as you would expect to see them at the stages
listed:
Mitotic metaphase First polar body (metaphase)
Primary oocyte (metaphase) Ootid (G1)
Secondary oocyte (metaphase)
b) Given that the above-mentioned cells are from individuals heterozygous for two
independently segregating, autosomal loci, plum eyes and curled wings, place
appropriate symbols (of your designation) on chromosomes in the drawings you made
in part (A) above. Assume no crossing over, and there may be more than one correct
answer in some cases.
c) Assuming that a somatic G2 nucleus from one of the individuals in this scenario
contains about 8.0 picograms of DNA, how much nuclear DNA would you expect in
each of the cells mentioned above?
In addition to highly repetitive and unique DNA sequences, a third category of DNA
sequences exists. What is it called, and what types of elements are involved in it?
A) composite DNA; telomeres and heterochromatin
B) dominant DNA; euchromatin and heterochromatin
C) multiple gene family DNA; hemoglobin and 5.0S RNA
D) moderately repetitive DNA; SINEs, LINEs, and VNTRs
E) permissive DNA; centromeres and heterochromatin
Assume that a cross is made between AaBb and aabb plants and that all the offspring
are either AaBb or aabb. These results are consistent with the following circumstance:
A) complete linkage.
B) alternation of generations.
C) codominance.
D) incomplete dominance.
E) hemizygosity.
List, in order of appearance, all the cell types expected to be formed during (a)
spermatogenesis and (b) oogenesis.
Forms of inheritance that do not follow typical Mendelian patterns and that appear to be
more influenced by the parent contributing the most cytoplasm to the embryo are
grouped under the general heading of ________.
A) sex-linked inheritance
B) neo-Mendelian inheritance
C) extrachromosomal inheritance
D) suppressive inheritance
E) dominance and/or recessiveness
A protein is 300 amino acids long. Which of the following could be the number of
nucleotides in the section of DNA that codes for this protein? (Remember: DNA is
double-stranded.)
A) 3
B) 100
C) 300
D) 500
E) 1800
(a) Assume that A + T/G + C equals 0.5 in one strand of DNA. What is the ratio of these
bases in the complementary strand? (b) If A + G/T + C equals 0.5 in one strand, what is
the ratio of these bases in the complementary strand?
Name at least two typical characteristics of a DNA cloning plasmid?
The genes for light eyes (lt; light) and straw bristles (stw; straw) are tightly linked on
chromosome 2 in Drosophila melanogaster. The Malpighian tubes of lt larvae and
adults are maternally affected in that Malpighian tubes oflt/lt organisms, whose mothers
were lt+/lt and have more yellow pigment than those from lt/lt mothers. There is no
maternal effect associated with the straw locus. Give the phenotypes of the offspring
from the following crosses.
List at least three levels or types of genetic regulation in eukaryotes.
What are QTLs and RFLPs?
In the accompanying diagram, what type of control, positive or negative, is operating?
Given the following numbers, calculate the mean: 10, 12, 14, 16, 18.
Regarding the mitotic cell cycle, what is meant by a checkpoint?
When transcription factors interact with DNA, is the resulting genetic control typically
positive or negative?
Name the typical phases of the bacterial growth cycle in liquid culture medium.
In zoo animals, inbreeding often occurs because of a lack of a sufficient pool of
breeding individuals. Under such conditions, what two characteristics are often
exhibited among inbred organisms?
Assume that a Chi-square test was conducted to test the goodness of fit to a 3:1 ratio
and that a Chi-square value of 2.62 was obtained. Should the null hypothesis be
accepted? How many degrees of freedom would be associated with this test of
significance?
A particular cross gives a modified dihybrid ratio of 9:7. What phenotypic ratio would
you expect in a testcross of the fully heterozygous F1 crossed with the fully recessive
type? Diagram the testcross using A,a,B,b as symbol sets.
In what way will the discipline called metagenomics contribute to human health and
welfare?
There is some indication that the code is in some way ordered; a certain pattern exists.
Describe an observation that supports this view.
The dog (Canis familiaris) genome has recently been sequenced. About how many of
the dog’s genes are shared with humans?
Describe the action of the enzyme transposase.
Describe the cellular and molecular function of the ras gene family and the
consequences of mutations in ras.
Assuming a typical monohybrid cross in which one allele is completely dominant to the
other, what ratio is expected if the F1s are crossed?
Jacob, Wollman, and others developed a linkage map of E. coli that is based on time.
What form of recombination is involved in generating a linkage map based on time?