Term
In a genetic experiment, the offspring from the first cross are considered to be the _________ generation.
a. testcross
b. second filial
c. parental
d. backcross
e. first filial |
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Definition
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Term
Which of the following terms does not refer to a type of mating cross?
a. Reciprocal cross
b. Dominant cross
c. Testcross
d. Dihybrid cross
e. Monohybrid cross |
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Definition
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Term
A _____________ is a cross between an unknown and a homozygous recessive individual.
a. monohybrid
b. testcross
c. dihybrid
d. backcross
e. controlled |
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Definition
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Term
A rare recessive trait in a pedigree is indicated by which pattern of inheritance?
Select one:
a. diagonal
b. both vertical and horizontal
c. horizontal
d. vertical, horizontal and diagonal
e. vertical |
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Definition
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Term
In a monohybrid cross AA × aa, what proportion of heterozygotes is expected among the F2 offspring?
Select one:
a. all are heterozygous
b. 1/4
c. none are heterozygous
d. 1/2
e. 3/4 |
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Definition
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Term
| In a dihybrid cross AAbb × aaBB, what proportion of the F2 offspring is expected to be homozygous for at least one gene? Select one: a. all are homozygotes b. 1/2 c. all are heterozygotes d. 1/4 e. 3/4 |
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Definition
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Term
In the dihybrid cross AaBb × aabb, what proportion of individuals are expected to be homozygous for both genes in the F1 generation?
Select one:
a. all are heterozygotes
b. 1/4
c. all are heterozygotes
d. 1/2
e. 3/4 |
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Definition
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Term
Among the dihybrid crosses below, which will produce a 1:1 phenotypic ratio?
Select one:
a. AaBb × AaBb
b. AABB × aabb
c. AaBb × aabb
d. AaBB × aaBB
e. AAbb × aaBB |
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Definition
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Term
Among the dihybrid crosses below, which will give a 1:1:1:1 ratio?
Select one:
a. AaBB × aaBB
b. AAbb × aaBB
c. AaBb × AaBb
d. AABB × aabb
e. AaBb × aabb |
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Definition
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Term
Assume that in guinea pigs, dark brown fur (B) is dominant to black fur (b). If you mate a black guinea pig with a homozygous brown guinea pig, what proportion of the progeny will be homozygous?
Select one:
a. all
b. 1/2
c. 1/4
d. 3/4
e. none |
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Definition
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Term
A phenotype reflecting a new combination of genes occurring during gamete formation is called
Select one:
a. heterozygous.
b. an independent assortment.
c. a multihybrid cross.
d. a recombinant type.
e. homozygous. |
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Definition
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Term
Through the analysis of data obtained through the human genome project, scientists have identified a gene of unknown function that is highly conserved throughout the vertebrate lineage. These scientists used gene targeting to create mutant mice to study the function of this newly identified gene. What genetic approach does this represent?
Select one:
a. Reverse genetics
b. Forward genomics
c. Monohybrid cross
d. Forward genetics
e. Dihybrid cross |
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Definition
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Term
The frequency with which a specific allele occurs in a population is the ___________.
Select one:
a. wildtype frequency
b. genome frequency
c. recombinant frequency
d. gene frequency
e. allele frequency |
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Definition
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Term
A trait encoded by a gene with only one wildtype allele is considered
Select one:
a. monoallelic
b. polydactylic
c. polymorphic
d. polyallelic
e. monomorphic |
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Definition
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Term
Genes that contribute to the phenotype attributed to one or more other genes are referred to as
Select one:
a. dominant epistatic genes
b. recessive epistatic genes
c. codominant genes
d. modifier genes
e. dominant genes |
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Definition
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Term
If an enzyme in Drosophila is functional at room temperature but inactive at 37◦C, then we consider room temperature to be the _____________ temperature.
Select one:
a. active
b. permissive
c. modifier
d. restrictive
e. inactive |
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Definition
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|
Term
An interaction between non-allelic genes that results in the masking of a phenotype is called ___________.
Select one:
a. epistasis
b. epigenesis
c. codominance
d. dominance
e. parastasis |
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Definition
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Term
Which phenotypic ratio is indicative of incomplete dominance in the F2 generation following an F1 selfcross?
Select one:
a. 1:1
b. 2:1
c. 1:2:1
d. 3:1
e. 9:3:3:1 |
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Definition
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Term
A person with O blood type cannot safely receive a blood transfusion from donors with which of the following blood types?
Select one:
a. B
b. AB
c. A
d. O
e. all except O |
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Definition
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Term
A black labrador retriever male was mated with 3 females with identical genotypes at the B (brown) and E (extension) genes. Assuming that only B and E genes contribute to the outcome of these matings and the combined litters produced a total of 6 brown, 7 black and 4 yellow pups, what were the most likely genotypes of the parents if the male genotype is listed first?
Select one:
a. bbEe x bbee
b. BBee x bbEE
c. BbEe x bbEe
d. bbEe x bBEe
e. BbEe x bbee |
|
Definition
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Term
Mutations in the XPD gene can cause trichothiodystrophy. This disease is pleiotropic with brittle hair due to a defect in keratin crosslinking. Four unaffected patients were reported that exhibited brittle hair when they presented with a high fever and XPD mutations were subsequently identified in these patients. What term best describes the genetic association between fever and brittle hair.
Select one:
a. hypostatic interaction
b. recessive epistasis
c. incomplete dominance
d. temperature sensitive mutation
e. recessive phenotype |
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Definition
| temperature sensitive mutation |
|
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Term
Klinefelter's syndrome is characterized by:
Select one:
a. females with XO
b. females with XY
c. males with XYY
d. males with YO
e. males with XXY |
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Definition
|
|
Term
Down syndrome is caused by trisomy:
Select one:
a. 18
b. 23
c. 13
d. 22
e. 21 |
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Definition
|
|
Term
The S phase of the cell cycle is immediately preceded by the
Select one:
a. G2
b. R2
c. G1
d. C1
e. M |
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Definition
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|
Term
In meiosis, crossing over occurs in
Select one:
a. Cytokinesis
b. Prophase II
c. Prophase I
d. Anaphase I
e. Anaphase II |
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Definition
|
|
Term
The separation of homologous chromosomes into separate daughter cells occurs during which stage of mitosis?
Select one:
a. Telophase
b. none
c. Anaphase
d. Prophase
e. Metaphase |
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Definition
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|
Term
One form of colour blindness is X-linked and recessive. A woman with normal vision whose father was colour blind married a man with normal vision but whose father was colour blind. The probability that there children are colour blind is best expressed as
Select one:
a. 0% of females and 50% of males
b. 50% of females and 100% of males.
c. none are affected, they will all be carriers.
d. 50% of females and 0% of males
e. 50% of females and 50% of males |
|
Definition
| 0% of females and 50% of males |
|
|
Term
_____________ are alternate forms of a gene.
Select one:
a. alleles
b. linkage groups
c. mutations
d. diads
e. genotypes |
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Definition
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|
Term
______________________ is a form of cell division that typically gives rise to 2 identical daughter cells.
Select one:
a. telophase
b. meiosis
c. mitosis
d. prophase
e. cytokinesis |
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Definition
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|
Term
_________________ refers to the interaction of two alleles at a single locus in which the heterozygotes do not resemble either homozygote.
Select one:
a. incomplete dominance
b. multimorphic
c. pleiotropy
d. polymorphism
e. codominance |
|
Definition
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|
Term
Sickle cell anemia is a recessive genetic disorder occurring in individuals carrying two copies of the HBβS allele of the β-globin gene. The wildtype HbβA allele of the β-globin gene...________________.
Select one:
a. is dominant to HBβ^S.
b. is codominant with HBβ^S.
c. exhibits a variety of dominance relationships with HBβS.
d. is recessive to HBβ^S.
e. is incompletely dominant to HBβ^S. |
|
Definition
| exhibits a variety of dominance relationships with HBβS. |
|
|
Term
Pure breeding sweet pea plants with white flowers are crossed to yield an F1 generation with all purple flowers. Following a F1 selfcross, a 9:7 ratio of purple to white flowers in the F2 generation was observed. What is the most plausible explanation?
Select one:
a. This is an example of incomplete dominance involving 2 loci.
b. This represents a monohybrid cross with incomplete dominance.
c. This represents an example of dominant epistasis.
d. Alleles at two independent assorting genes are exhibiting complementary gene action.
e. Flower colour is controlled by two genes that are linked. |
|
Definition
| Alleles at two independent assorting genes are exhibiting complementary gene action |
|
|
Term
In a dihybrid cross, the A allele exhibits incomplete dominance over the a allele while the B allele similarly exhibits incomplete dominance over the b allele. The A allele controls seed colour while the B allele controls flower colour. The A and B genes sort independently. How many possible combinations of phenotypes can be generated?
Select one:
a. 16
b. 25
c. 4
d. 3
e. 9 |
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Definition
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|
Term
What is the phenotype of fruit flies (Drosophila melanogaster) carrying two copies of the X chromosome and 1 copy of the Y chromosome?
Select one:
a. normal female
b. hermaphrodite
c. Klinefelter syndrome
d. Dies before hatching
e. normal male |
|
Definition
|
|
Term
What combination listed below best describes chromosome number and DNA content during metaphase I?
Select one:
a. the cells are tetrads with 2C DNA content.
b. the cells are diploid with 4C DNA content.
c. the cells are diploid with 2C DNA content.
d. the cells are tetraploid with 4C DNAcontent.
e. the cells are haploid with 2C DNA content. |
|
Definition
| the cells are diploid with 4C DNA content. |
|
|
Term
In females (human), meiosis __________.
Select one:
a. is initiated once a month.
b. is symmetrical.
c. is initated following fertilization.
d. is asymmetrical.
e. is initiated following puberty. |
|
Definition
|
|
Term
The ________ progeny were usually analyzed in x-linked gene mapping experiments.
Select one:
a. dihybrid
b. F1
c. trihybrid
d. male
e. female |
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Definition
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|
Term
| When mapping linked genes on autosomes using a two point cross, dihybrids are crossed with ________________. Select one: a. individuals with similar genotype. b. individuals with similar phenotype. c. homozygous recessive individuals. d. other dihybrids e. homozygous dominant individuals. |
|
Definition
| homozygous recessive individuals |
|
|
Term
_____________ are physical microscopic evidence of crossing over.
Select one:
a. Centrosomes
b. DNA double strand breaks
c. Recombinants
d. Crossovers
e. Chiasmata |
|
Definition
|
|
Term
In a 3 point cross, the recombinant phenotypes corresponding to ___________ are the least frequent.
Select one:
a. double crossover events
b. F1 recombinants
c. single crossover events
d. parental recombinants
e. F2 recombinants |
|
Definition
|
|
Term
Injection of mice with Streptococcus pneumoniae that grow as smooth colonies in culture results in _________.
Select one:
a. embryonic lethality
b. death of the mice
c. chronic pneumonia
d. none of the other answers
e. no phenotype |
|
Definition
|
|
Term
The transforming principle studied by Avery, MacLeod, and McCarty could be destroyed or removed by _________.
Select one:
a. shear forces.
b. RNase
c. DNase.
d. protease
e. ultracentrifugation |
|
Definition
|
|
Term
The Hershey-Chase Waring blender experiment determined that _________________________.
Select one:
a. bacteriophage replicate by semi-conservative DNA synthesis.
b. bacteriophage integrate into the host genome, becoming insensitive to external shear forces.
c. bacteriophage are made up of roughly equal amounts of protein and DNA using radioactive sulphur and phosphorous.
d. radiolabelled bacteriophage DNA enters host cells during infection but that radiolabelled proteins do not
e. all of the other answers are correct. |
|
Definition
| radiolabelled bacteriophage DNA enters host cells during infection but that radiolabelled proteins do not |
|
|
Term
ll DNA polymerases synthesyze DNA in a __________.
Select one:
a. 5' to 3' direction.
b. C-terminal to N-terminal direction. C-terminal to N-terminal direction.
c. nucleus.
d. 3' to 5' direction.
e. N-terminal to C-terminal direction. |
|
Definition
|
|
Term
Meselson and Stahl used a _______ isotope of ____________ to disprove the conservative and dispersive models of DNA replication.
Select one:
a. heavy, nitrogen
b. heavy, sulphur
c. radioactive, sulphur
d. radioactive, phosphate
e. radioactive, nitrogen |
|
Definition
|
|
Term
DNA replication is initiated at ________________ of replication.
Select one:
a. semi-conservative sites
b. termination sites
c. bidirectional sites
d. origins
e. promoters |
|
Definition
|
|
Term
DMC1 protein facilitates strand invasion during _______.
Select one:
a. mitotic recombination.
b. double strand break repair.
c. branch migration.
d. resolution of holliday junctions.
e. meiotic recombination. |
|
Definition
|
|
Term
Resolution of holliday junctions in the same plane results in _______.
Select one:
a. genetic loss.
b. bidirectional fork migration.
c. homoduplex formation.
d. failed crossover.
e. meiotic crossover. |
|
Definition
|
|
Term
Phosphodiester bonds are present in __________.
Select one:
a. DNA, RNA and proteins
b. DNA
c. proteins
d. RNA
e. DNA and RNA |
|
Definition
|
|
Term
In meiotic recombination, the Dmc1 protein is _________________________.
Select one:
a. is involved in resolving holiday junctions.
b. is required for mitotic recombination.
c. binds to DNA strand breaks induced by ionizing radiation.
d. is similar to the bacterial recA protein.
e. binds to double stranded DNA in a sequence-dependent manner. |
|
Definition
| is similar to the bacterial recA protein. |
|
|
Term
What is strand invasion?
Select one:
a. The process in which the 3' end of a DNA pairs with a homologous strand of DNA, displacing its complementary strand.
b. The process in which the 5' end of a DNA pairs with a homologous strand of DNA, displacing its complementary strand.
c. The process in which the 3'end of RNA pairs with a homologous strand of DNA, displacing its complementary strand.
d. The process in which the 5'end of RNA pairs with a homologous strand of DNA, displacing its complementary strand.
e. The process in which two DNA strands simultaneously displace their homologous strands in a homologous DNA. |
|
Definition
| The process in which the 3' end of a DNA pairs with a homologous strand of DNA, displacing its complementary strand. |
|
|
Term
The rate of forward mutations is generally __________ than the rate of reverse mutation.
Select one:
a. it dependents on whether the mutation gives rise to a dominant or recessive trait.
b. less than
c. none of these other answers is correct.
d. equal to
e. greater than |
|
Definition
|
|
Term
A large body of evidence indicates that in response to UV light, pyrimidime dimers that form at CC, CT and TC sequences are highly mutagenic while pyrimidine dimers at TT sites are less mutagenic. This result is thought to occur because translesion polymerases insert A residues opposite the damaged bases. What class of substitution does this represent?
Select one:
a. inversions
b. transversions
c. deletions
d. transpositions
e. transitions |
|
Definition
|
|
Term
What is the reverse complementary sequence of GTACCTAGTTCAAC?
Select one:
a. GTTGAACTGAATAC
b. CATGGATCAAGTTG
c. GTACCTAGTTCAAC
d. CATGGATCAAGTTG
e. GTTGAACTAGGTAC |
|
Definition
|
|
Term
Deamination of cytosine gives rise to ________________.
Select one:
a. thymidine
b. uracil
c. hypoxanthine
d. guanine
e. homocysteine |
|
Definition
|
|
Term
Which of the following altered sequences contains a transversion relative to the parental sequence?
Select one:
a. GTACCT to GCACCT
b. GTACCT to GTATCT
c. GTACCT to GTATTT
d. GTACCT to GTTCCT
e. GTACCT to GTACTT |
|
Definition
|
|
Term
Which of the following DNA repair pathways in error prone?
Select one:
a. Nucleotide excision repair
b. Homology-directed repair
c. Non-homologous end-joining
d. Base excision repair
e. DNA mismatch repair |
|
Definition
| Non-homologous end-joining |
|
|
Term
Which of these disorders is characterized by genomic instability and cancer predisposition? Check all that apply.
Select one or more:
a. Cockayne syndrome
b. Bloom syndrome
c. Ataxia telangiectasia
d. Werner's syndrome
e. Fanconi's anemia |
|
Definition
b. Bloom syndrome Correct
c. Ataxia telangiectasia Correct
d. Werner's syndrome Correct
e. Fanconi's anemia Correct |
|
|
Term
Consider 2 reverse complementary sequences that make up a double stranded segment of DNA within a transcribed region of DNA. The first is 5'-ATGTACTCAGCCGTAGCGTAA-3' and its reverse complementary sequence is 3'-TACATGAGTCGGCATCGCATT-5'. What is the sequence of the RNA transcript through this region, assuming that the second sequence represents the template strand?
Select one:
a. 3'-ATGTACAGTCGGCATCGCGTA-5'
b. 5'-AUGUACUCAGCCGUAGCGUAA-3'
c. 3'-AUGUACAGUCGGCAUCGCGUA-5'
d. 5'-ACGCGAUGCCGACUGUACAUA-3'
e. 5'-TACATGTCAGCCGTAGCGCAA-3' |
|
Definition
| 5'-AUGUACUCAGCCGUAGCGUAA-3' |
|
|
Term
Translate the RNA sequence in #1 to the corresponding amino acid sequence using Figure 8.3 of your textbook (or any other source of the genetic code). Which amino acid sequence is correct?
Select one:
a. Met-Tyr-Val-Ala-Ser -Ala-Leu
b. Met-Tyr-Val-Ala-Ser-Ala-Stop
c. Met-Tyr-Ser-Ala-Val-Ala-Stop
d. Met-Tyr-Ser-Ala-Val-Ala-Leu
e. Leu-Arg-Tyr-Gly-Stop |
|
Definition
| Met-Tyr-Ser-Ala-Val-Ala-Stop |
|
|
Term
Which of the following ratios is indicative of codominance?
Select one:
a. 1:2:1
b. 3:1
c. 9:3:1
d. none of the above
e. 9:7 |
|
Definition
|
|
Term
Drosphila have 2n=8 chromosomes. How many linkage groups are present in Drosophila sperm?
Select one:
a. 0
b. 3
c. 1
d. 4
e. 2 |
|
Definition
|
|
Term
DNA replication is _________.
Select one:
a. conservative
b. liberal
c. dispersive
d. semiconservative
e. semidispersive |
|
Definition
|
|
Term
DNA polymerase reads sequence in the _________.
Select one:
a. N-terminal to C-terminal direction
b. 5' to 3' direction
c. 5' to 2' direction
d. 3' to 5' direction
e. C-terminal to N-terminal direction |
|
Definition
|
|
Term
In human cells, there is/are ______________.
Select one:
a. 23 origins of replication per genome
b. 2 origins of replication per chromosome
c. 1 origins of replication per cell
d. 1 origin of replication per chromosome
e. many origins of replication per chromosome |
|
Definition
| many origins of replication per chromosome |
|
|
Term
In tRNA, inosine is formed by the deamination of ________.
Select one:
a. adenosine
b. hypoxanthine
c. uracil
d. cytosine
e. thymidine |
|
Definition
|
|
Term
Dominant negative mutations refer to ________________.
Select one:
a. mutations that are codominant over the wildtype allele at the same locus.
b. mutations that are completely dominant over the wildtype allele at the same locus.
c. mutations that are incompletely dominant over the wildtype allele at the same locus.
d. mutations that are dominant over wildtype but that confer a negative phenotype (disease state for example).
e. mutations whose gene products inhibit the function of a wildtype protein. |
|
Definition
| mutations whose gene products inhibit the function of a wildtype protein. |
|
|
Term
How many hydrogen bonds form between guanine and cytosine in B-form DNA?
Select one:
a. 4
b. 2
c. 1
d. 3
e. 0 |
|
Definition
|
|
Term
If a woman is affected with an extremely rare autosomal dominant disorder, what is the probability that her first grandchild will be affected with the disease?
Select one:
a. 25%
b. 100%
c. 75%
d. 0%
e. 50% |
|
Definition
|
|
