Prokaryotic and eukaryotic ribosomes are structurally and chemically identical.
Doubling the chromosomes of a sterile species hybrid with colchicine or cold shock is a
method used to produce a fertile species hybrid (amphidiploid).
Heterogeneous nuclear RNA is a primary transcript in eukaryotes that is processed prior
to involvement in translation.
In recombinant DNA technology, a YAC is an enzyme isolated from a large South
American, four-legged mammal.
An individual with Turner Syndrome has no Barr bodies.
Postreplication repair is a system that responds after damaged DNA has escaped repair
and failed to be completely replicated.
Sequencing the dog genome has indicated that a single locus on chromosome 15 may
play a major role in genetically distinguishing large dog breeds from small dog breeds.
Exon shuffling is a term used to describe the movement of modular protein domains
during protein evolution. As a result different genes specify similar domains.
Transcription in eukaryotes is generally influenced by enhancers just as in prokaryotes.
An intron is a section of an RNA that gets spliced out.
Assume that an organism has a haploid chromosome number of 7. There would be 14
chromosomes in a monoploid individual of that species.
Mendel’s discoveries were well received and understood by his contemporaries.
The chromosomal aberration that causes cri du chat syndrome can be referred to as a
segmental deletion.
Genetic involvement in development appears to be achieved, at least in part, by variable
gene activity.
The enzyme polynucleotide phosphorylase is capable of generating a random assembly
of ribonucleotides.
Biotechnology has yet to produce a single useful product for a human health condition.
Inbreeding by itself can change gene frequencies.
The trp and lac operons are both subject to forms of control that are typically called
negative.
Humans have more DNA and more genes than any other organism.
Direction of shell coiling in Lymnaea peregra is influenced by a maternal effect.
A tumor-suppressor gene normally functions to suppress cell division.
A 3″ poly-A tail and a 5″-cap are common components of prokaryotic RNAs.
The ABO blood group locus in humans provides an example of epistasis.
An organism with a haploid number of 10 will produce 1024 combinations of
chromosomes at the end of meiosis.
Assume that a mutation occurs in the gene responsible for the production of
hexosaminidase A, such that only about 50% of the enzyme activity is found in the
heterozygote compared with a homozygous normal individual. If heterozygotes are
phenotypically normal, we would say that the mutant allele is recessive to its normal
allele.
There is a general inverse relationship between DNA content and organismic
complexity.
An individual with Klinefelter syndrome generally has one Barr body.
Although mutation is the original source of genetic variation, its influence on changing
allelic frequencies is relatively minor.
An individual with Patau syndrome would be called a triploid.
To test Mendel’s Law of Segregation, the experimenter needs a minimum of two
contrasting forms of a gene.
Some restriction endonucleases are capable of producing blunt ends; others can
generate “sticky” ends.
Regarding the lactose utilization system in E. coli, a constitutive mutant is one in which
the three enzymes are produced regardless of the presence or absence of lactose.
As more is learned about cancer, it has become clear that cancer, with few exceptions,
has no genetic basis.
The availability of a large series of monozygotic and dizygotic twins often enhances
studies on the genetic basis of human behavior.
What conclusion has been reached regarding the genetic status of schizophrenia using
genome-wide association studies?
A) A single dominant gene is involved.
B) No single gene or allele makes a significant contribution.
C) A single recessive gene is involved.
D) Several dominant genes located on the X chromosome cause this disease.
E) No more than three loci are involved in the expression of schizophrenia.
Quantitative inheritance involves the interaction of a number of gene loci. The pattern
of genetic transmission typical of quantitative inheritance is ________.
A) discontinuous distributions such as 3:1
B) typical of Mendelian inheritance
C) continuous variation of phenotypic expression
D) a 9:3:3:1 ratio
E) usually a pattern that clearly reflects dominance and recessiveness
Which of the following clusters of terms accurately describes DNA as it is generally
viewed to exist in prokaryotes and eukaryotes?
A) double-stranded, parallel, (A + T)/C + G) = variable, (A + G)/(C + T) = 1.0
B) double-stranded, antiparallel, (A + T)/C + G) = variable, (A + G)/(C+ T) = 1.0
C) single-stranded, antiparallel, (A + T)/C + G) = 1.0, (A + G)/(C + T) = 1.0
D) double-stranded, parallel, (A + T)/C + G) = 1.0, (A + G)/(C + T) = 1.0
E) double-stranded, antiparallel, (A + T)/C + G) = variable, (A + G)/(C + T) = variable
Which of the following contains the three posttranscriptional modifications often seen
in the maturation of mRNA in eukaryotes?
A) 5″-capping, 3″-poly(A) tail addition, splicing
B) 3″-capping, 5″-poly(A) tail addition, splicing
C) removal of exons, insertion of introns, capping
D) 5″-poly(A) tail addition, insertion of introns, capping
E) heteroduplex formation, base modification, capping
Which term is commonly used to describe the production of valuable proteins in
genetically modified plants and animals?
A) animal farming
B) tuna farming
C) biopharming
D) culturing
E) genetic production
In which cellular organelle do the three posttranscriptional modifications often seen in
the maturation of mRNA in eukaryotes occur?
A) nucleus
B) cytoplasm
C) mitochondrion
D) lysosome
E) Golgi
In 1953, Watson and Crick published a paper that described the structure of DNA.
Assume that a man who carries an X-linked gene has children. Assuming normal
meiosis and random combination of gametes, the man would pass this gene to
________.
A) half of his daughters
B) all of his daughters
C) all of his sons
D) half of his sons
E) all of his children
In Drosophila, the sequential order of the function of segmentation genes is ________.
A) gap, segment-polarity, pair-rule
B) pair-rule, transdeterminal, gap
C) transdeterminal, gap, pair-rule
D) gap, pair-rule, segment-polarity
E) segmentational, helical, spherical
Bacteriophages engage in two interactive cycles with bacteria. What are these cycles?
A) lytic and lysogenic
B) insertion and replication
C) auxotrophic and prototrophic
D) heteroduplex and homoduplex
E) negative and positive
The diploid chromosome number of an organism is usually represented as 2n. Humans
have a diploid chromosome number of 46. What would be the expected haploid
chromosome number in a human?
A) 92
B) 16
C) 12
D) 24
E) 23
Briefly define transformation and describe the relationship between the phenomenon of
transformation and the discovery that DNA is the genetic material in bacteria.
The autosomal (not X-linked) gene for brachydactyly, short fingers, is dominant to
normal finger length. Assume that a female with brachydactyly in the heterozygous
condition is married to a man with normal fingers. What is the probability that
a) their first child will have brachydactyly?
b) their first two children will have brachydactyly?
c) their first child will be a brachydactylous girl?
In the 1600s, William Harvey studied reproduction and development. What is the term
given to the theory which states that an organism develops from the fertilized egg by a
succession of developmental events that lead to an adult?
A) preformation
B) sequential pattern formation
C) equational transformation
D) transduction
E) epigenesis
A certain type of congenital deafness in humans is caused by a rare autosomal (not
X-linked) dominant gene.
a) In a mating involving a deaf man and a deaf woman (both heterozygous), would you
expect all the children to be deaf? Explain your answer.
b) In a mating involving a deaf man and a deaf woman (both heterozygous), could all
the children have normal hearing? Explain your answer.
c) Another form of deafness is caused by a rare autosomal recessive gene. In a mating
involving a deaf man and a deaf woman, could some of the children have normal
hearing? Explain your answer.
The ant, Myrmecia pilosula, is found in Australia and is named bulldog because of its
aggressive behavior. It is particularly interesting because it carries all its genetic
information in a single pair of chromosomes. In other words, 2n = 2. (Males are haploid
and have just one chromosome.) Which of the following figures would most likely
represent a correct configuration of chromosomes in a metaphase I cell of a female?
A)
B)
C)
D)
E)
A cross was made between homozygous wild-type female Drosophila and
yellow-bodied male Drosophila. All of the resulting offspring were phenotypically wild
type. Offspring of the F2 generation had the following phenotypes:
Based on this information:
a) Is the mutant gene for yellow body behaving as a recessive or dominant?
b) Is the yellow locus on an autosome or on the X chromosome?
Complementarity in a genetic sense refers to the polymerization of nucleotides in DNA.
The following coat colors are known to be determined by alleles at one locus in horses:
palomino = golden coat with lighter mane and tail
cremello = almost white
chestnut = brown
The following table gives ratios obtained in matings of the above varieties:
a) Assign gene symbols for the genetic control of coat color on the basis of these data.
b) Diagram the last two matings.
The Lygaeus mode of sex determination is the ________.
A) XY/XX scheme
B) XX/XO scheme
C) XO/YY scheme
D) hermaphroditic scheme
E) scheme based on single translocations in the X chromosome
In a healthy male, how many sperm cells would be expected to be formed from (a) 400
primary spermatocytes? (b) 400 secondary spermatocytes?
A) (a) 800; (b) 800
B) (a) 1600; (b) 1600
C) (a) 1600; (b) 800
D) (a) 400; (b) 400
E) (a) 100; (b) 800
If a typical G1 nucleus is 2n and contains 2C (two complements) of DNA, a prophase I
cell is 2n and contains 4C of DNA.
According to Charles Darwin and Alfred Wallace, variations followed a more
continuous pattern. According to Mendel’s model, variation due to dominance-recessive
relationships followed a more ___________ form.
A) abstract
B) smooth
C) discontinuous
D) normalized
E) transferred
Many instances involving genetically modified organisms, especially food crops, will
be entering the human food chain in the years to come. On what basis are genetically
modified foods considered safe to eat?
A) They are only slightly toxic.
B) All products to be cleared for human consumption have been personally tested by all
members of the regulatory agency.
C) Because of the possible economic impact of rigorous testing, such food products are
minimally tested in sheep and cattle.
D) Each genetically modified food product is screened for its resistance to antibiotics.
E) Genetically modified food products are considered safe if they are found not toxic or
allergenic or have other negative physiological effects.
Which method is often used to analyze proteins and nucleic acids by physical
separation when estimating genetic variation in populations?
A) electrophoresis
B) centrifugation
C) absorption spectrophotometry
D) fluorometry
E) in situ hybridization
The transforming principle discovered by Griffith is RNA.
Assume that a cross is made between AaBb and aabb plants and that the offspring fall
into approximately equal numbers of the following groups: AaBb, Aabb, aaBb, aabb.
These results are consistent with the following circumstance:
A) independent assortment.
B) alternation of generations.
C) complete linkage.
D) incomplete dominance.
E) hemizygosity.
The enzyme glucose-6-phosphate dehydrogenase deficiency (G6PD) is inherited as a
recessive gene on the X chromosome in humans. A phenotypically normal woman
(whose father had G6PD) is married to a normal man.
a) What fraction of their sons would be expected to have G6PD?
b) If the husband had G6PD, would it make a difference in your answer in part (a)?
Which of the following general mechanisms appear to be involved in the formation of
cancer cells?
A) genomic instability, DNA repair failure, chromatin modifications
B) inversions, operon formation, methylation
C) RNA failure, DNA phosphorylation, phosphorylation of adenyl cyclase
D) transdetermination, mutation, allosteric interactions
E) suppression, tabulation, projection
If 15% of the nitrogenous bases in a sample of DNA from a particular organism is
thymine, what percentage should be cytosine?
A) 15%
B) 30%
C) 35%
D) 40%
E) 70%
When referring to attenuation in regulation of the trp operon, it would be safe to say
that when there are high levels of tryptophan available to the organism, ________.
A) the trp operon is being transcribed at relatively high levels
B) translational termination is likely
C) transcriptional termination is likely
D) tryptophan is inactivating the repressor protein
E) ribosomes are stalling during translation of the attenuator region
Some mutagens cause genetic changes that can be “corrected” by reexposing cells to the
same mutagen. Other mutagens do not behave in this way. Provide one example of each
of these two types of agents and describe the mutational changes caused in DNA.
Explain why some mutagens behave in one way, while others do not.
Name the pyrimidines and the purines in DNA.
The ara operon is controlled by a regulator protein that exerts ________.
A) induction and expression
B) expressivity and penetrance
C) positive and negative control
D) upward and reverse control
E) top and bottom control
Under strictly controlled conditions, a probe can be used that will hybridize only with
its complementary sequence and not with other sequences that may vary by as little as
one nucleotide. What are such probes called?
A) generation-specific probes
B) short, variable repeats
C) VNTRs
D) microsatellites
E) allele-specific oligonucleotides (ASOs)
Assume that two genes are 80 map units apart on chromosome II of Drosophila and that
a cross is made between a doubly heterozygous female and a homozygous recessive
male. What percent recombination would be expected in the offspring of this type of
cross?
Much has been learned about the relationship between genes and gene products through
the use of the mold Neurospora. What specific attributes make Neurospora a good
organism for such studies?
Provide a general definition for the term speciation.
What primary ingredients, coupled with DNA polymerase I, are needed for the in vitro
synthesis of DNA?
Among dogs, short hair is dominant to long hair and dark coat color is dominant to
white (albino) coat color. Assume that these two coat traits are caused by independently
segregating gene pairs. For each of the crosses given below, write the most probable
genotype (or genotypes if more than one answer is possible) for the parents. It is
important that you select a realistic symbol set and define each symbol below.
Assume that for cross (d), you were interested in determining whether fur color follows
a 3:1 ratio. Set up (but do not complete the calculations) a Chi-square test for these data
[fur color in cross (d)].
Which phenotypic ratio is likely to occur in crosses of two completely dominant,
independently segregating gene pairs when both parents are fully heterozygous?
Individuals with the same genetic background and a high degree of homozygosity are
said to be isogenic. Of what value are isogenic strains in genetic studies?
Describe three distinct genetic regions of the human Y chromosome.
Name three modes of inheritance that are influenced by the sex of individuals.
Is the accompanying figure DNA or RNA? Is the circle closer to the 5″ or 3″ end?
Briefly describe the mutant status of the HD gene.
The accompanying table is a set of experimental results relating the growth (+) of
Neurospora on several media (MM = minimal medium). Based on the information
provided, present the biochemical pathway and the locations of the metabolic blocks.
The genes for mahogany eyes and ebony body are approximately 25 map units apart on
chromosome III in Drosophila. Assume that a mahogany-eyed female was mated to an
ebony-bodied male and that the resulting F1 phenotypically wild-type females were
mated to mahogany, ebony males. Of 1000 offspring, what would be the expected
phenotypes, and in what numbers would they be expected?
Why is variegation in four o’clock plants determined by the phenotype of the ovule
source?
Present an overview of the research dealing with the genetics of behavior in small
mammals (mice or rats) and Drosophila.
When and in which journal did Watson and Crick publish their now-famous paper
entitled “Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic
Acid.”
What is the name of the process by which bacterial colonies (cells) are transferred from
one agar plate to another, maintaining the same spatial pattern?
Define determination and differentiation.
The various characteristics of organisms that result from their genetic makeup are
collectively referred to as an organism’s ________.