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WorksheetsBiol 2170 Exam 4
Total questions: 120
Worksheet time: 2hrs 0mins
Name
Class
Date
1.
Which of the following explains the difference between VNTRs and RFLPs?
a)
In VNTRs, we are looking at sequence differences in noncoding DNA; in RFLPs we are looking at sequence differences in genes
b)
In VNTRs we are looking at the size differences resulting from different restriction sites being present; in RFLPs we are looking at the number of times a sequence is repeated
c)
In VNTRs we are looking at sequence differences in genes; in RFLPs we are looking at sequence differences in noncoding DNA
d)
In VNTRs, we are looking at the number of times a sequence is repeated; in RFLPs we are looking at size differences resulting from different restriction sites being present
2.
The ability to perceive a bitter taste from certain chemicals including PTC has been linked to certain alleles. Which of the following would provide an explanation for the fact that almost all nonhuman primates have the "taster" phenotype, whereas the human population has a significant percentage of "nontaster" phenotypes?
a)
Nonhuman primates only eat foods that are not bitter, so the phenotype of tasting bitter compounds was not selected against
b)
The advantage to not being able to taste bitter compounds means that humans are more likely to eat vegetables and hence live longer than nonhuman primates
c)
The advantage to being able to taste bitter compounds would keep you from eating poisonous compounds, an advantage not needed in the human population anymore
d)
Humans needed the ability to not taste bitter compounds, so the mutation happened
3.
Imagine that you are a detective who has identified a suspect in a homicide. You acquire a small amount of blood from the crime scene and hand it over to your lab. The lab carries out PCR for one polymorphism, and it returns as a match to your suspect. Is this enough to arrest your suspect?
a)
Yes, a match between DNA fingerprints is always definitive proof that the two sources are the same individual
b)
Yes, the chance that your suspect will have the same polymorphism at a single site as a drop of blood from a random individual is about 1 in 50,000; this is enough to arrest the suspect
c)
No, your lab should assess additional polymorphisms; a single polymorphism does not constitute a DNA fingerprint
d)
No, the small amount of blood you acquired from the crime scene will not provide enough genetic material for PCR to be carried out efficiently; more than a single drop of blood is needed to provide enough raw material for analysis
4.
Insertions and deletions of single nucleotides:
a)
cause missense mutations
b)
cause cancer
c)
cause frameshift mutations
d)
shorten chromosomes
5.
The enzyme _____ repairs 99% of mismatched bases immediately during replication.
a)
DNA ligase
b)
DNA polymerase
c)
uracyl glycosylase
d)
AP endonuclease
6.
A family can share a genetic risk of developing cancer if:
a)
A germ-line mutation in one of the genes implicated in the cancer occurred in an ancestor
b)
the cancer is caused by somatic cell mutations
c)
a somatic cell mutation in one of the genes implicated in the cancer occurred in an ancestor
d)
the cancer is caused by germ-line mutations
7.
Point mutations that cause amino acid replacements are called:
a)
nonsense mutation
b)
stop mutation
c)
synonymous (silent) mutation
d)
non synonymous (missense) mutation
8.
Any heritable change in the genetic material is ____
a)
a mutation
b)
detrimental to the organism, and potentially, to the species
c)
usually the result of a reactive chemical or radiation
d)
usually evident in an abnormal number of chromosomes
9.
The enzyme _____ repairs breaks in the DNA sugar-phosphate backbone.
a)
uracyl glycosylase
b)
DNA polymerase
c)
AP endonuclease
d)
DNA ligase
10.
The enzyme ______ repairs breaks in the DNA sugar-phosphate backbone
a)
uracyl glycosylase
b)
DNA polymerase
c)
AP endonuclease
d)
DNA ligase
11.
Beneficial mutations are those that increase survival or reproduction in the prevailing environment.
a)
True
b)
False
12.
A population of mosquitoes is exposed to the pesticide DDT for several generations. At the end of that time, most individuals in the population are resistance to DDT. The MOST likely reason is that:
a)
Somatic mutations in the original population were passed on the the subsequent generations
b)
DDT caused the mutations that led to resistance
c)
Some individuals in the original population had the mutations that led to resistance
d)
Random mutations in each generation made mosquitoes resistant to DDT
13.
Which mutations in an animal somatic cell would be inherited by the next generation?
a)
synonymous mutations
b)
deletions
c)
point mutations
d)
none of the choices are correct
14.
The relatively large number of new mutations that occur in the human genome in each generation is tolerable because:
a)
compared to other organisms, changes in our proteins have relatively little effect on our cells' structure and functions
b)
we have excellent DNA repair mechanisms
c)
most of our genome is noncoding DNA, so few mutations affect our proteins
d)
we have excellent protein repair mechanisms
15.
Alleles are alternate molecular forms of a gene
a)
true
b)
false
16.
Only polymorphisms that add or remove restriction sites can be useful in DNA typing.
a)
true
b)
false
17.
Saying that a SNP is associated with a disease means that if you possess that particular SNP, you will end up with that disease.
a)
true
b)
false
18.
There are no discernible phenotypic effects for an individual with the genotype XXY.
a)
true
b)
false
19.
While a mutation will not always change the phenotype of an individual, it will always change the genotype.
a)
true
b)
false
20.
Variable tandem repeats and restriction fragment length polymorphisms are synonymous- both consist of repeated fragments of DNA with the same sequence (i.e., GTAGTAGTA).
a)
true
b)
false
21.
The difference between a single nucleotide polymorphism (SNP) and a point mutation is that:
a)
a SNP becomes permanently incorporated into the genome whereas a point mutation does not.
b)
a point mutation is when a base pair is changed to a different base pair, whereas a SNP is when the base pair differs among individuals in a population
c)
a point mutation can be corrected by various repair mechanisms, whereas SNP cannot
d)
a SNP can be corrected by various repair mechanisms, whereas a point mutation cannot
22.
In a person with the genotype XXY, we can tell that nondisjunction took place in the mother.
a)
true
b)
false
23.
Imagine that you know two sisters-Rose and Sam- both of whom smoke. Rose has a mutation in the gene for alpha-1 antitrypsin, whereas Sam does not. Which of the following statements is true regarding these sisters?
a)
Rose is predisposed to develop emphysema, but if Sam does, this will be a random occurrence; environmental factors or lifestyle choices (such as smoking) have not been associated with emphysema
b)
Given that a mutation in alpha-1 antitrypsin serves a "protective" function against the development of emphysema, Rose will not develop this disease but Sam will
c)
It is possible that neither Rose nor Sam will develop emphysema; however, the fact that both sisters smoke- added to the mutation that Rose carries- increase their chances of developing this disease
d)
As both sisters smoke, Rose and Sam will certainly develop emphysema; however, given her mutation, Rose will likely develop a much more serious form of the disease
24.
For a SNP with three alleles, how many different diploid genotypes are possible?
a)
3
b)
4
c)
5
d)
6
25.
Which of the following statements is true regarding nondisjunction?
a)
Nondisjunction occurring during meiosis II results in two gametes that completely lack certain chromosomes
b)
Nondisjunction only contributes to the development of trisomy 21 and not trisomy 13 or 18
c)
Nondisjunction only occurs between autosomes; the sex chromosomes are rarely affected by nondisjunction
d)
none of the answers are correct
26.
A new gene is discovered that dramatically aids in the digestion of fish. You hypothesize that populations with a history of being near the shoreline would have more copies of this gene than populations found farther inland. How would you classify this genetic difference?
a)
RFLP
b)
CNV
c)
VNTR
d)
SNP
27.
A couple has a baby that is monosomic for the X chromosome. This most likely occurred during meiosis because:
a)
either there was an inversion of the X chromosome or there was a duplication in the X chromosome and crossover occurred
b)
there was translocation of part of another chromosome onto the X chromosome
c)
there was nondisjunction of the sister chromatids
d)
there was an inversion in the X chromosome and crossover occurred
28.
Until 20 or 20 years ago, people with cystic fibrosis (CF) wouldn't live long enough to reproduce. CF is a homozygous recessive condition, leading researchers to think that over time the incidence of CF would decrease because the allele would be removed from the gene pool. The results actually indicate that the rate of CF is on the rise. Based on what you know about why certain genotypes and phenotypes persist in a population, which of the following could be a likely explanation for why the rate of CF is on the rise?
a)
The heterozygous condition is beneficial, much like what we see with sickle cell trait
b)
People are traveling more, so when people from different areas reproduce, more mutations will result
c)
We are being subjected to more mutations as a population due to more pollution
d)
The population is increasing, and more people mean more mutations
29.
After doing PCR on the same region between two individuals, you notice that each person's DNA yielded pieces of different sizes. Which of the following is the most likely explanation?
a)
A mistake was made during PCR
b)
A mistake was made during gel electrophoresis
c)
This is an example of VNTRs
d)
This is an example of RFLPs
30.
The biggest difference between CNV and VNTRs is the size of the DNA being studied.
a)
true
b)
false
31.
A patient is about to receive chemotherapy and the doctor is concerned with dispensing the correct dosage. Certain people cannot metabolize this type of chemical because they have a mutation that changes a codon for valine into one for asparagine. How would such a mutation be classified?
a)
RFLP
b)
CNV
c)
PCR
d)
SNP
32.
A phenotype always refers to something that you can see with your eyes, like hair color or eye color.
a)
true
b)
false
33.
Phenotypes:
a)
can be subject to environmental conditions
b)
only result from gene transcription
c)
are always expressed in the same way
d)
always result solely from the actions of a single gene
34.
Genetic studies have identified an allele (Δ32) that seems to provide protection against HIV. Which of the following would most likely explain the reason why our population has this mutation?
a)
This mutation likely benefited the human population against some other related pathogen
b)
Our bodies are designed to protect us against a myriad of pathogens, and the immune system was preparing for future viruses like HIV
c)
This mutation is very likely a neutral mutation
d)
This mutation was likely induced in the genome by the presence of HIV virus
35.
Mendel's principle of independent assortment corresponds to which part of meiosis?
a)
random pairing of homologues during prophase I
b)
random alignment of homologues on the metaphase plate during metaphase I
c)
separation of chromosomes in anaphase I
d)
random alignment of homologues on the metaphase plate during metaphase II
36.
Genes that fail to show independent assortment are said to be linked.
a)
True
b)
False
37.
If the concept of blending inheritance were true, would variation increase or decrease over time?
a)
increase
b)
decrease
c)
stay the same
38.
An allele is:
a)
One of several forms of a gene
b)
The location of a gene on a chromosome
c)
The expression of a trait in an individual
d)
The particular combination of genes for a given trait in a given organism
39.
When Mendel crossed true-breeding yellow-seed plants with true-breeding green-seed plants, the offspring were phenotypically:
a)
green-seed plants
b)
a mixture of yellow and green seeds
c)
made up of a combination of yellow and green alleles
d)
yellow-seed plants
40.
Which of the following represents the expected genotypes of an F1 generation consisting of 16 individuals from a cross of a true-breeding black (BB) rabbit and a true-breeding white (bb) rabbit?
a)
8 BB, 8 bb, 0 Bb
b)
4 BB, 4 bb, 8 Bb
c)
0 BB, 0 bb, 16 Bb
d)
16 BB, 0 bb, 0 Bb
41.
Mendel's principle of segregation corresponds to what part of meiosis?
a)
condensation of chromosomes in prophase I
b)
alignment of homologs in metaphase I
c)
separation of homologs in anaphase I
d)
separation of daughter chromatids in anaphase II
42.
A trait with incomplete penetrance is one that:
a)
is expressed in only some offspring of affected individuals
b)
is only expressed in some of the individuals that have the genotype for that trait
c)
can be expressed differently in different individuals that have the genotype for that trait
d)
is only expressed in homozygous recessive individuals
43.
Flower color in snapdragons is due to a gene with incomplete dominance CRCR plants have red flowers, CRCW have pink flowers, and CWCW plants have white flowers. What types and ratios of flower color are expected among the progeny of a cross of pink x white?
a)
all pink
b)
1 pink : 1 white
c)
1 red : 2 pink : 1 white
d)
1 red : 1 pink
44.
Which of the following processes would result in gametes that violate Mendel's principle of segregation?
a)
nondisjunction
b)
independent assortment
c)
dominance
d)
epistasis
45.
If you crossed a true-breeding yellow-seed plant (AA) with a heterozygous yellow-seed plant (Aa), offspring:
a)
genotypes would be 1 AA : 1 aa and phenotypes would be 1/2 yellow-seed plants and 1/2 green-seed plants
b)
genotypes would be 1 AA: 2 Aa
c)
genotypes would be 1 Aa : 1 aa
d)
genotypes would be 1 AA: 1 Aa
46.
Mendel's experiments with garden peas differed from those of other plant hybridizers of the time in that:
a)
Mendel studied true-breeding strains, focused on a small number of easily contrasted traits, and quantified results
b)
Mendel focused on a small number of easily contrasted traits, and quantified results
c)
Mendel quantified his results and looked for statistical patterns instead of simply noting the presence or absence of a trait among a group of offspring
d)
Mendel studied true-breeding strains indeed of poorly defined material
47.
Which repair mechanism can repair multiple nucleotides?
a)
mismatch repair
b)
base excision repair
c)
nucleotide excision repair
48.
How is elastase inhibited?
a)
by binding to the target cell
b)
by binding alpha1AT
c)
by binding to RNA
49.
What is epistasis?
a)
when one gene effects the expression of another gene
b)
the recessive allele
c)
none of the answers are correct
d)
the dominant allele
50.
Additions or deletions of three nucleotides are not very harmful.
a)
True
b)
False
51.
Genes that are linked are assorted independently of each other.
a)
True
b)
False
52.
What are mutation hotspots?
a)
region where nucleotides cannot be mutated
b)
region where nucleotides are not repaired after mutation
c)
region where nucleotides are prone to mutation
53.
Unbalanced translocations can be tolerated in an organism.
a)
False
b)
True
54.
What do the alleles AS indicate?
a)
mild form of sickle cell anemia
b)
no sickle cell anemia
c)
severe form of sickle cell anemia
55.
What does VNTR stand for?
a)
vacant nucleotides tandem reciprocals
b)
variable number tandem repeats
c)
varied nucleotide tandem repeats
56.
Does a neutral mutation have observable effects?
a)
yes
b)
no
57.
Why do humans have a lower rate of mutations?
a)
because humans do not get as many mutations
b)
because most of the DNA is noncoding
c)
because humans have repair mechanisms that repair mutations
58.
How is an F2 generation created?
a)
crossing P1 and P1
b)
crossing F1 and P1
c)
crossing F1 and F1
d)
crossing F1 and F2
59.
Which of the following is not a female part of a plant?
a)
stigma
b)
ovules
c)
anthers
d)
ovary
60.
What disease is recognized by XXY sex chromosomes?
a)
huntington's
b)
turner
c)
klinfelter's
61.
Transposable elements are pieces of DNA that can "transpose" in the genome.
a)
true
b)
false
62.
What is the difference between somatic and germ line mutations?
a)
somatic only in organism, germ line is passed to offspring
b)
somatic is passed to offspring, germ line only in organism
c)
there is no difference between somatic and germ line mutations
63.
When does nondisjunction have a chance of producing normal genes?
a)
Meiosis I
b)
Meiosis II
64.
Which mutation is the worst?
a)
nonsense
b)
missense
c)
silent
65.
How many alleles can be present in an individual?
a)
4
b)
6
c)
1
d)
2
66.
Mutagens are chemicals that decrease the likelihood of a mutation occurring.
a)
True
b)
False
67.
If a karyotype shows missing or extra chromosomes this is evidence of nondisjunction.
a)
true
b)
false
68.
What is the first mechanism to repair mutations in DNA?
a)
mismatch repair
b)
polymerase
c)
NER
d)
ligase
69.
What is the difference between DNA polymerase and ligase?
a)
polymerase repairs sugar phosphate backbone, and ligase proofreads
b)
polymerase proofreads and ligase repairs sugar phosphate backbone
70.
What is a missense mutation?
a)
mutation occurs but amino acid doesn't change
b)
mutation occurs and amino acid is changed
c)
a mutation occurs and amino acid changes early to a stop codon
71.
What are the Mendelian ratios of the F2 generation phenotype?
a)
1:2:1
b)
2:1
c)
9:3:3:1
d)
3:1
72.
In a pedigree:
a)
males are circles; females are squares
b)
females are circles; males are squares
c)
males are triangles, females are squares
d)
females are circles, males are triangles
73.
True-breeding plants are typically heterozygous for most genes.
a)
true
b)
false
74.
Why do RNA viruses and retroviruses have such a high rate of mutation?
a)
because RNA polymerase is an unstable enzyme
b)
because RNA is more fragile than DNA and therefore more likely to be damaged
c)
because viral polymerases lack a proofreading mechanism
d)
none of the choices are true
75.
Although Gregor Mendel's work was not originally considered by his contemporaries to be groundbreaking, Mendel's principles of segregation and independent assortment were "rediscovered" nearly two decades after his death.
a)
true
b)
false
76.
Sites in the genome that are more susceptible to mutations than others are called:
a)
genes
b)
hotspots
c)
mutation spots
d)
risk factors
77.
As a result of the principle of blending inheritance, no gray rabbits actually exist. Over time, gray fur in rabbits has been diluted to white fur.
a)
true
b)
false
78.
Only germ-line mutations are transmitted to the progeny.
a)
True
b)
False
79.
A testcross of an organism of unknown genotype is done when the organism is crossed to an organism that is:
a)
a heterozygote
b)
a dominant homozygote
c)
a recessive homozygote
d)
all choices are correct
80.
Normally, in corn, genes for waxy and virescent kernel appearance are in the same chromosome. In a certain stock, however, it was found that these two genes are in different chromosomes. Which chromosomal aberration would explain this?
a)
translocation
b)
inversion
c)
duplication
d)
deletion
81.
Mutation rates (per nucleotide per replication):
a)
are lower in organisms with larger genomes
b)
are similar across organisms
c)
are higher in organisms with larger genomes
d)
are highest in viruses
82.
The number of new mutations in organisms following a round of genome replication:
a)
generally increases with larger genomes
b)
generally decreases with larger genomes
c)
is similar independent of genome size
d)
is highest in bacteria
83.
Any deviation in normal gene dosage is lethal.
a)
true
b)
false
84.
Sickle-cell anemia results from what type of mutation?
a)
missense
b)
frameshift
c)
silent
d)
nonsense
85.
Which of the following would you expect to have the lowest rate of point mutations per replication?
a)
fruit flies
b)
RNA viruses
c)
humans
d)
bacteria
86.
Any DNA "damage" is considered to be a mutation, even if it is immediately corrected by the action of DNA polymerase.
a)
true
b)
false
87.
Chronic myelogenous leukemia (CML) is caused when a segment of chromosome 9 and a segment of chromosome 22 both break off and switch places. How is this mutation classified?
a)
transpostion
b)
reciprocal translocation
c)
deletion
d)
inversion
88.
Which of the following statements is true regarding a chromosome deletion?
a)
chromosome deletions do not affect gene dosage
b)
if a deletion eliminates the centromere, the chromosome is still passed on during cell division
c)
small chromosomal deletions usually have serious and often fatal consequences on an organism
d)
none of the choices are correct
89.
Incomplete penetrance is synonymous with variable expressivity, as in both instances a trait may or may not be expressed.
a)
true
b)
false
90.
In base excision repair, a whole segment of DNA is removed and resynthesized.
a)
true
b)
false
91.
Which of the following statements concerning cancer and mutations is correct?
a)
cancer can only occur with a mutation in somatic cells
b)
cancer can only occur with a mutation in germ cells
c)
usually multiple mutations are required in different genes to cause cancer
d)
usually a single mutation is all that is required to cause cancer
92.
Which of the following mutations would most likely have the most severe consequence?
a)
missense
b)
frameshift
c)
silent
d)
addition of a codon
93.
DNA polymerase is responsible for the process called mismatched repair.
a)
true
b)
false
94.
Which of the following statements about mutations is true? A mutation:
a)
may leave the amino acid sequence of a protein unchanged
b)
will result in a different phenotype
c)
will be corrected
d)
will be passed onto offspring
95.
The rates of evolutionary change in DNA:
a)
can only be determined in conserved genes
b)
are constant among different gene families and thus are used to estimate the time of divergence
c)
are highly variable among different gene families
d)
are constant in gene families with a diversity of members
96.
Which of the following is the likely explanation for a flower showing multiple sectors with different coloration?
a)
the result of the plant being tetraploid
b)
the result of a deletion
c)
the result of a germline mutation
d)
the result of transposable elements
97.
A researcher has carried out Giesma staining on a set of human chromosomes, and has arranged these chromosomes into a karyotype. He notices that in a homologous pair, a band is missing from one of the chromosomes. This likely resulted from:
a)
a deletion
b)
an inversion
c)
a reciprocal translocation
d)
either a deletion or a reciprocal translocation
98.
Dosage refers to the number of copies of each gene in a cell.
a)
true
b)
false
99.
Which of the following enzymes is responsible for initiating certain types of base excision repair?
a)
DNA polymerase
b)
DNA ligase
c)
AP endonuclease
d)
DNA trail glycosylase
100.
Which of the following statements is true concerning the work of Esther and Joshua Lederberg?
a)
Their work relied on a technique of bacterial culture known as "replica plating," and demonstrated that mutations occur randomly in organisms
b)
Their work demonstrated that mutations are determined by an organism's "needs".
c)
Their work demonstrated that mutations in organisms arise in response to their environmental conditions
d)
Their work relied on a technique of bacterial culture known as "replica plating"
101.
Imagine that a rancher has a herd of cattle with brown hides and short horns. All of his cattle are also relatively short in stature. If all of these traits were true breeding, what could you say about the progeny of these cattle?
a)
The progeny of these cattle will be short in stature and have brown hides and short horns.
b)
It is impossible to determine the traits of such progeny—they will likely demonstrate different hide colors, horn lengths, and heights.
c)
The progeny of these cattle will have short horns, but a variety of hide colors and heights.
d)
The progeny of these cattle will have brown, black, white, and spotted hides.
102.
Animals that sexually reproduce are _____ and produce _____ gametes.
a)
diploid; diploid
b)
diploid; haploid
c)
haploid; diploid
d)
haploid; haploid
103.
Consider a polyploid plant that has several copies of each of its genes. This plant will likely die prematurely, given this high gene dosage.
a)
true
b)
false
104.
Which of the following is true of blending inheritance?
a)
blending inheritance explains the disappearance of a trait several generations after it appeared
b)
blending inheritance leads to an increase in variation over time
c)
blending inheritance allows for rare variants of traits to increase in frequency
d)
none of the answers are correct
105.
A silent mutation is a mutation that only occurs in noncoding regions of DNA.
a)
true
b)
false
106.
In eukaryotic organisms with large genomes, the usual reason that many inversion breakpoints do not disrupt genes is because the breaks occur:
a)
in the telomeres
b)
in the centromere
c)
in the nucleolus of noncoding DNA
d)
all choices are correct
107.
Chromosomal aberrations:
a)
can be caused by errors during cell division
b)
are typically only seen in the elderly
c)
are usually fixed by DNA polymerase
d)
can be caused by methylation
108.
You are working in a lab studying a gene and notice that there are many other genes in the same organism that code for similar proteins. This is most likely the result of:
a)
reciprocal translocation
b)
transposition
c)
duplication and divergence
d)
inversion
109.
Which of the following mechanisms would most likely be involved in repairing a single point mutation?
a)
mismatch repair and/or excision repair
b)
base excision repair and/or nucleotide excision repair
c)
base excision repair
d)
nucleotide excision repair
110.
The fact that humans have a relatively large number of mutations per genome per generation when compared to other organisms can be explained by which of the following statements?
a)
humans are so complex we have multiple proteins doing the same job
b)
humans have multiple proteins doing the same job, and our cells don't divide as often as other organisms
c)
human cells don't divide as often as those of other organisms
d)
most of a human's DNA is noncoding, so most of the mutations are neutral
111.
Which of the following is true regarding linked genes?
a)
Linked genes are located on the same chromosome.
b)
Linked genes are located in the same chromosome and do not follow patterns of independent assortment.
c)
Linked genes demonstrate independent assortment.
d)
Linked genes are always located on different chromosomes.
112.
Which of the following represents the expected genotypes of an F2 generation consisting of 8 individuals from an initial cross of a true-breeding black (BB) rabbit and a true-breeding white (bb) rabbit?
a)
8 progeny: 4 BB, 4 bb, 0 Bb
b)
8 progeny: 0 BB, 0 bb, 8 Bb
c)
8 progeny: 8 BB, 0 bb, 0 Bb
d)
8 progeny: 2 BB, 2 bb, 4 Bb
113.
You cross a true-breeding stock of black (BB) mice with skinny (SS) toes to a stock of white (bb) mice with fat (ss) toes. From this, you produce an F1 generation of black mice with skinny toes (Bb,Ss). If the single genes responsible for coat color and toe appearance do not sort independently, then you would expect to see:
a)
more than 75 percent of your F2 black mice with skinny toes.
b)
more than 25 percent of your F2 black mice with fat toes.
114.
While doing a pedigree analysis of a royal family from a Pacific Island nation, you notice two parents with the same genetic disease who have four children. All four of the girls have the disease, but when they marry unaffected individuals, none of the 16 grandchildren has the disease. If this disease is controlled by a single gene, then the most likely explanation would be that the disease is:
a)
a spontaneous mutation.
b)
dominant and is only seen in homozygous dominant individuals.
c)
recessive and is only seen in homozygous recessive individuals such as the affected girls.
d)
dominant and is seen in heterozygous or homozygous dominant individuals.
115.
Why was the theory of blending inheritance eventually disproven?
a)
It was eventually disproven by demonstrating segregation of alleles for the inheritance of many traits in diverse types of organisms.
b)
Although the theory of blending inheritance accounted for a great deal of variation in a population, the theory of natural selection yielded explanations for every phenotype observed in a population.
c)
It was based on the fact that the phenotypes of progeny of a given cross typically resemble either parent—and never present "intermediate" phenotypes (i.e., such as grey fur).
d)
The theory of blending inheritance suggested that inheritance is a diversifying force, whereas it is actually a homogenizing force.
116.
In which of the following populations would you expect to have the most genetic diversity within the group?
a)
a stock of tomato plants that is not true breeding
b)
the F1 generation of tomato plants from the cross of two different true-breeding stocks
c)
a true-breeding stock of tomato plants
117.
Which of the following genotypes would result in a true-breeding stock?
a)
AA or aa, but not Aa
b)
Aa, but not AA or aa
c)
aa, but not Aa or AA
d)
AA or Aa or aa
118.
Why was it important for Mendel to remove the anthers from pea plants in his experiments when crossing two different true-breeding pea plants?
a)
to prevent self-fertilization
b)
to protect the pea plants from environmental pollen
c)
to stimulate the pea plants to ovulate
d)
to make sure self-fertilization would occur
119.
A true breeding black rabbit is crossed with a true breeding white rabbit to produce an F1generation with 8 individuals. If blending inheritance were true, which of the following would represent the expected phenotype of the F1 generation?
a)
6 black rabbits, 2 white rabbits, 0 grey rabbits
b)
8 black rabbits, 0 white rabbits, 0 grey rabbits
c)
0 black rabbits, 0 white rabbits, 8 grey rabbits
d)
2 black rabbits, 2 white rabbits, 4 grey rabbits
120.
If the phenotype of pea pod color is determined by incomplete dominance, the combination of an allele for yellow seeds and an allele for green seeds yields blue seeds. Therefore, you would expect the F2 generation from an original cross of true-breeding green stock with true-breeding yellow stock to be:
a)
25 percent yellow, 50 percent blue, 25 percent green.
b)
67 percent green, 33 percent yellow.
c)
100 percent blue.
d)
67 percent blue, 33 percent yellow.
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