Finals Flashcards
(127 cards)
1
Q
All DNA polymerases synthesize new DNA by adding nucleotides to the _____ of the growing DNA chain.
A
3’ OH
2
Q
Which of the following statements are true of all DNA Polymerases in E. Coli?
a. the enzyme synthesizes DNA strands in a 5’ to 3’ direction
b. the enzyme adds dNTP to the growing DNA strand
c. the enzyme is able to act as a 3’ to 5’ exonuclease
d. the enzyme is able to act as a 5’ to 3’ exonuclease
e. the enzyme synthesizes DNA strands in a 3’ to 5’ direction
f. the enzyme requires the presence of a 3’ OH group to add new nucleotides to
A
I THINK: A, B, C, F
3
Q
What type of synthesis occurs on the leading strand?
A
Continuous
4
Q
Okazaki fragments
(Select all)
a. are due to discontinuous DNA synthesis
b. are found on the leading strand
c. are found on the lagging strand
d. are created because DNA polymerase synthesizes in a 3’ to 5’ direction
A
a, c
5
Q
If ribonucleotides were depleted from a cell during S phase. how would DNA synthesis be affected? (ignore energetic considerations.)
A
Replication would cease because ribonucleotides are requires to initiate DNA synthesis
6
Q
An individual that is homozygous for a loss of function mutation in the telomerase gene would
A
lose some of its genetic material with every round of cell division
7
Q
Maize has a total of 20 chromosome in a diploid cell (2N = 20). During G1, there will be a total of _____ telomeres present.
(Select all)
a. 10
b. 40
c. 80
d. 20
A
b
8
Q
Meiosis is used for
(Select all)
a. repair
b. sexual reproduction
c. asexual reproduction
d. growth
A
b
9
Q
Maize has a total of 20 chromosomes in diploid cell (2N = 20). During G1, there will be a total of ____ homologous pair present.
A
10
10
Q
During prophase of mitosis:
(select all)
a. homologous pairs of chromosomes synapse
b. replicated chromosomes become more compact
c. replicated chromosomes lines up in the middle of the cell
d. recombination (crossing over) occurs
e. the spindle begins to form
f. centrosomes migrate to the poles of the cell
A
b, e, f
11
Q
A diploid somatic cell from a fruit fly has a total of 8 chromosomes (2n = 8). As in humans, sex chromosomes determine sex: XX in females and XY in males. What is the total number of telomeres in a fly cell during prophase of mitosis
A
32
12
Q
A dividing eukaryotic cell is treated with a drug that inhibits the molecular motors associated with kinetochores. At which cell cycle stage would it stop?
A
M (metaphase)
13
Q
What is the stage of meiosis is which chromosomes synapse?
A
prophase I
13
Q
During prophase I of meiosis:
(Select all)
a. recombination takes place
b. replicated chromosomes begin to become more compact
c. the spindle begins to form
d. the centrosomes migrate to the poles of the cell
e. homologous chromosomes synapse
f. the replicated chromosomes line up in the middle of the cell
A
i think: a, b, d, e
14
Q
Mitosis is used for:
(Select all)
a. growth
b. sexual reproduction
c. repair
d. asexual reproduction
A
a, c, d
15
Q
Maize has a total of 20 chromosomes in a diploid cell (2N = 20). During G2, there will be a total of ____ telomeres present.
A
i think: 80
16
Q
A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42). As in humans, sex chromosomes determine sex: XX in females and XY in males. What is the total number of chromatids in a rat cell in prophase II of meiosis?
A
42
17
Q
Which of the following statements are true of mitosis:
(Select all)
a. replication occurs during interphase
b. synapsis occurs during prophase
c. the nuclear membrane breaks down during prophase
d. paired homologous chromosomes line up on the metaphase
e. haploid daughter cells are produced
f. sister chromatids are separated during anaphase
A
a, c, f
18
Q
A diploid somatic cell from a rat has a total of 42 chromosomes (2n = 42). As in humans, sex chromosomes determine sex: XX in females and XY in males. What is the total number of chromatids present in the cell during metaphase I of meiosis?
A
84
19
Q
Diploid cells are capable of going through
a. meiosis
b. mitosis
c. both
A
c
20
Q
linked genes always exhibit…
A
recombination frequencies of less than 50%
21
Q
Recombination
(select all)
a. occurs during prophase I of meiosis
b. occurs during prophase II of meiosis
c. occurs between sister chromatids of homologous chromosomes
d. occurs between non homologous chromosomes
e. occurs during prophase of mitosis
f. allows scientists to estimate the distance between genes linked together on the same chromosome
g. occurs between non sister chromatids of homologous chromosomes
A
a, f, g
22
Q
Imagine an individual with the following genotype: A B c / a b C. If a is 10 map units from b and c is 20 map units from b… and assuming that there is no interference.. what is the chance that this individual will produce a gamete carrying alleles a b c.
A
9%
23
Q
You are doing lab work with a new species of beetle. You have isolated lines that breed true for either blue shells and long antenna, or green shells and short antenna. Crossing these lines yields F1 progeny with blue shells and long antenna. Crossing F1 progeny with beetles that have green shells and short antenna yield the following progeny:
Blue shell, long antenna- 82
Green shell, short antenna- 78
Blue shell, short antenna -37
Green shell, long antenna- 43
Total- 240
Assuming that the genes are linked, what is the map distance between them in cM?
A
33.3
24
Genes C and D are linked on the same chromosome and 14 map units apart from each other. An individual CCDD is mated with an individual ccdd. The F1 offspring are mated with a tester and 400 offspring are produced. How many of these offspring should be CcDd?
172
25
A testcross is performed on an individual to examine three linked genes. The most frequent phenotypes of the progeny were Abc and aBC, and the least frequent phenotypes were abc and ABC. What was the genotype of the heterozygous individual that is testcrossed with the correct order of the three genes?
cAb / CaB
26
what is a plasmid?
i think: a small circular piece of non chromosomal DNA
27
In a PCR reaction, the treatment of the sample of 95 C replaces the action of..
i think: helicase
28
In humans the average GC content is ~40% and is composed of approx. 3 billion base pairs in the haploid genome. If you were to use an oligonucleotide primer with the sequence GGGGGG, you would expect it to bind to ~ _____ locations.
(numerical value)
29
What is an operon?
A cluster of genes with a single regulatory element controlled by a regulatory product
30
The cluster of genes that are part of the operon...
(select all)
a. each code for a different protein
b. each code for the same protein
c. each code for different proteins that are involved in the same biochemical pathwat
d. each code for different proteins that are involved in different biochemical pathways
a, c
31
In order to be homozygous an individual must have...
Two copies of the same allele on homologous chromosomes
32
Segregation of alleles occurs during...
anaphase I
33
T/F: In addition to segregation of alleles, the Law of Segregation implies that an organisms phenotype is controlled by the combination of alleles, one from each parent.
True
34
The Law of independent Assortment applies to
(select all)
a. one gene
b. two genes on different chromosomes
c. two genes on the same chromosome that are far apart.
d. two genes on the same chromosome that are close together.
b,c
35
Because of the law of independent assortment, you can think about the genes separately and ____ their probability of producing a particular result.
multiply
36
Imagine a cross between two individuals AaBb x aaBb. What fraction of the offspring will have both dominant traits?
3/8
37
The Law of Independent Assortment works the way it does because of the way that chromosomes line up during...
metaphase I
38
T/F: In a chi-square test, the null hypothesis is always that the observed and expected values are in agreement with each other.
True
39
In order to determine the expected values in a chi-square test, you must
always multiply the total number of observations by any ratio that makes sense based upon your understanding of the nature of the cross.
40
In order to determine the critical value in a chi square test you must...
determine the degrees of freedom by identifying the number of phenotypic categories, subtracting 1 and looking up the appropriate value in a table.
41
T/F: If the chi square value is less than the critical value, you reject the hypothesis that the observations and expectations match.
False
42
T/F: If a trait is autosomal, the results of two reciprocal crosses involving pure breeds of opposite phenotypes, should produce the same phenotypic result.
True
43
Imagine reciprocal crosses are made between pure breeds of opposite phenotypic categories. If the cross using the female with the dominant trait and male with the recessive trait and all of the female offspring end up eith the recessive trait and all of the male offspring end up with the dominant trait the gene must be found on...
a Z chromosome
44
Sex linkage involves..
the presence of a gene on any sex determining chromosome that controls non sex specific traits.
45
If a female that has an X linked recessive trait is crossed with a male that does not hace the recessice trait, which are true?
(select all)
a. all of the female offspring will have the recessive trait
b. None of the offspring will have the recessive trait
c. None of the female offspring will have the recessive trait
d. Some of the offspring will have the recessive trait
e. 1/2 of the male offspring will have the recessive trait
f. all of the male offspring will have the recessive trait
c, d, f
46
IF a trait is sex influenced male dominant then the phenotype of individuals will be..
(select all)
a. males and females with the same genotype will always have the same phenotype
b. homozygous mutant males and females will have the mutant trait
c. homozygous non mutant males and females will not have the mutant trait
d. homozygous mutant males will have the mutant trait while the homozygous mutant females will not
e. heterozygous males will have the mutant trait while heterozygous females will not
f. heterozygous males will have the non mutant trait and heterozygous females will have the mutant characteristic.
b, c, e
47
Which of the following statements are true?
(Select all)
a. females with the proper genetic makeup can develop prostate cancer
b. males with the proper genetic makeup can develop prostate cancer
c. males with the proper genetic makeup can develop ovarian cancer
d. males with the proper genetic makeup can increase the chance that their daughters will develop ovarian cancer
b, d
48
T/F: Pedigrees are commonly used in the study of human genetics because it is nearly impossible to carry out controlled crosses for experimentation.
True
49
Which of the following statements are true about an autosomal recessive pedigree?
(Select all)
a. a mating of two affected individuals can produce unaffected offspring
b. a mating of two unaffected individuals can produce some affected and some unaffected offspring
c. mutant characteristics may skip generations
d. mutant characteristics always skip generations
e. mutant characteristics are more likely to show up in males than females.
b,c
50
Which of the following statements are true about autosomal dominant pedigrees?
(select all)
a. mutant characteristics must appear in every generation
b. mutant characteristics may appear in every generation
c. the mating of two affected individuals may produce unaffected offspring
d. the mating of two affected individuals must produce affected offspring
e. the mating of two unaffected individuals must produce affected offspring
f. the mating of two unaffected individuals never produce affected offspring unless a new mutation occurs
b c, f
51
An affected female mates with an unaffected male. Their daughter has the mutant trait but their son does not.
(Select all)
a. this trait could be autosomal recessive
b. this trait could be autosomal dominant
c. this trait could be X linked recessive
d. this trait could be X linked dominant
e. this trait could be Y linked
a, b, d
52
Jack does not have the trait, but his family has history of an autosomal recessive trait running through it. His paternal grand parents did not have the trait. His father did not have the trait. His paternal uncle did have the trait. Jack's mother's family has no history of this trait running in her family. Which of these statements must be true?
(Select all)
a. One of Jack's paternal grandparents must be homozygous dominant
b. both of Jack's paternal grandparents must be heterozygous
c. One of Jack's paternal grandparents must be homozygous recessive.
d. Jack's father must be heterozygous
e. Jack's father has a 1/2 chance of being heterozygous
f. Jack's father has 2/3 chance of being heterozygous
g. Jack has a 1/2 chance of being heterozygous
h. Jack has a 1/4 chance of being heterozygous
i. Jack has a 1/3 chance of being heterozygous
b, f, i
53
Gene has a 1/2 chance of being heterozygous for an autosomal recessive trait. His wife Allie has a 1/6 chance of being heterozygous for the same autosomal recessive trait. Neither of them have the trait, but what is the chance that they will have a child that does have the trait?
1/48
(1/2 dad Aa * 1/6 mom Aa* 1/4 kid aa)
54
T/F: Not all genes can assort independently from each other because there are many genes on every chromosome.
true
55
If an individual is heterozygous for two perfectly linked genes and they are in repulsion
(select all)
a. wherever A goes B will go with it during meiosis
b. wherever A goes b will go with it during meiosis
c. wherever a goes, b will go with it during meiosis
d. wherever a goes, B will go with it during meiosis
e. the AaBb individual will produce 4 different gametes
f. the AaBb individual will produce 2 different gametes.
b, d, f
56
T/F: Linkage violates the Law of Segregation.
false
57
A tester is ________for all genes being tested in a cross
homozygous recessive
58
If an individual heterozygous for two genes in a perfect linkage are grossed to a tester, then you would expect what of the offspring?
offspring to be divided evenly into two phenotypic groups
59
Recombination
(Select all)
a. breaks perfect linkage between alleles on the same chromosome
b. occurs 50% of the time
c. takes place during prophase of mitosis
d. takes place during prophase I of meiosis
e. takes place during prophase II of meiosis
f. rates are influenced by the distance between two genes
a, d, f
60
T/F: In order to calculate recombination frequency you simply add all of the non recombinant individuals and divide by the total number of offspring
false
61
Genetic distance
(select all)
a. is not related to the rate of recombination
b. is 100x the rate of recombination
c. can be measured in map units
d. can be measured in centimorgans
b, c, d
62
In order to test for linkage, you cross a tester to an individual heterozygous for two genes. You examine the progeny and perform a chi square test with the null hypothesis that
(select all)
a. the genes are perfectly linked and you will get a 1:1 ratio
b. the genes are imperfectly linked and you will get four phenotypic groups with various number of individuals in each group
c. the genes are assorting independently and you will expect a 1:1:1:1 ratio
d. if rejected confirms that the genes are assorting independently
e. if rejected confirms that the genes are linked
c, d
63
T/F: If you discover that the genes are linked then the two smallest phenotypic groupings represent the nonrecombinants.
False
64
If an individual is AaBb, with genes going through independent assortment, and crossed to a tester, you would expect what ratio?
1:1:1:1
65
T/F: The number of nonrecombinant gametes produced in a three point test cross should be the largest type of gametes generated.
True
66
If gene A is 10 map units from B (in the middle and B is 40 map units from C, you would expect ____% of your gametes to be the result of a double crossover. (Hint: think about the product rule)
4%
67
In order to determine the gene in the middle in a three point test cross, you will need to pay special attention to
the double crossovers.
68
We know that nonrecombinants are the most abundant gamete types and double recombinants are the least abundant. What about the single crossovers?
SCO1 will be more common than SCO2 if the distance between A and B is greater than the distance between B and C.
69
A three point test cross is made using an individual AaBbCc and a tester. 200 offspring are produced with the following phenotypes: ABc= 75, abC = 75, ADC = 3, abc = 2, AbC= 15, aBc = 15, aBC= 7, Abc= 8
Based on this information, which individuals are carying a double recombinant chromosome?
ABC, abc
70
A three point test cross is made using an individual AaBbCc and a tester. 200 offspring are produced with the following phenotypes: ABc = 75; abC = 75; ABC = 3; abc = 2; AbC = 15; aBc = 15; aBC = 7; Abc = 8. Based on this information, which gene is in the middle of the other two?
C
71
T/F: In order to calculate the distance between the first and middle gene (region 1) you simply add all the SCO 1 together and divide by the total.
False
72
A three point test cross is made using an individual AaBbCc and a tester. 200 offspring are produced with the following phenotypes: ABc = 75; abC = 75; ABC = 3; abc = 2; AbC = 15; aBc = 15; aBC = 7; Abc = 8. Based on this information, which individuals are carrying a nonrecombinant chromosome?
ABc, abC
73
A three point test cross is made using an individual AaBbCc and a tester. 200 offspring are produced with the following phenotypes: ABc = 75; abC = 75; ABC = 3; abc = 2; AbC = 15; aBc = 15; aBC = 7; Abc = 8. Based on this information, what was the linkage relationship of the three genes in the F1 heterozygous parent?
A is in repulsion to C but coupled to B
74
Genes A and B are on the same chromosome in a coupled relationship. The genes are 65 map units apart. When this individual goes through meiosis you would expect the gametes produced to be...
25% Ab
75
T/F: Double recombination events make it look like two genes are further apart than they really are.
False
76
T/F: If gene A is 30 map units from B and B is 10 map units from C, then A and C must be 40 map units apart.
False
77
What was the earliest evidence to suggest that chromosomes were the home of the genetic material?
placing all known mutations in a species into a number of linkage groups that always matched the number of homologous pairs of chromosomes
78
In order to identify chromosomes in a karyotype, scientists...
(Select all)
a. stop cells in the middle of division
b. stain the chromosomes with dyes to identify characteristic banding patterns
c. use DNA sequencing to identify sequences on the chromosomal body
d. measure the size of the chromosome
e. pay attention to the position of the centromere on the chromosome
a, b, d, e
79
Monosomy
(Select all)
a. is usually lethal in animals
b. is usually lethal in plants
c. is the result of nondisjunction
d. results in infertility in females human that are XO
e. causes developmental issues in plants due to improper protein dosage
a, c, d, e
80
Trisomy
(Select all)
a. is lethal in plants
b. is more likely to be lethal in animals, especially if the chromosome involved is large
c. is the result of nondisjunction
d. is the cause of Down's Syndrome
b, c, d
81
If a female with Down Syndrome mates with a normal male what fraction of children will have downs syndrome?
1/2 of the children will have downs
82
Rates of nondisjunction increase in humans
(Select all)
a. in older females due to the condition of meiotic cells arrested in prophase I
b. that have been exposed to cigarette smoke
c. males that consume large amounts of alcohol
d. men and women that consume large amounts of caffeine
all are correct
83
An individual that is carrying three copies of the same chromosome is considered
(Select all)
a. monosomic
b. trisomic
c. euploid
d. polyploid
e. aneuploid
f. triploid
b, e
84
T/F: Aneuploidy is caused by nondisjunction
true
85
Nondisjunction can occur during
(Select all)
a. anaphase of mitosis
b. anaphase I of meiosis
c. anaphase II of meiosis
d. telophase of mitosis
e. telophase I of meiosis
a, b, c
86
Translocations occur when a segment of chromosome....
breaks off and is reattached to a new chromosome location, either on another chromosome or at the opposite end of the same chromosome.
87
T/F: Individuals that are heterozygous for a reciprocal translocation involving nonhomologous chromosomes form a cruciform structure during prophase I of meiosis.
True
88
Alternate segregation in an individual heterozygous for a reciprocal translocation
a. occurs during anaphase I, when centromeres on the same side of the cruciform do in the same direction
b. occurs during anaphase I when centromeres on the same side of the cruciform go in opposite directions
c. produces 100% inviable gametes
d. produces 50% inviable gametes
e. produces 100% viable gametes
f. occurs in the 50% of meiotic events
g. occurs in 100% of meiotic events
b, e, f
89
Individual heterozygous for a reciprocal translocation have a reduced fertility
(Select all)
a. because of alternate segregation
b. because of adjacent 1 segregation
c. because of adjacent 2 segregation
d. because of recombination in the translocated region
b, c
90
Organisms that are tetraploid have..
have four copies of all chromosomes
91
Polyploidy can be the result of
(Select all)
a. nondisjunction of one homologous set of chromosomes
b. nondisjunction of all homologous sets of chromosomes in one parent
c. exposure of plant pollen colchicince
d. exposure of animals to excessive pressure or temperature while producing gametes.
b, c, d
92
A cross between a tetraploid and a diploid will produce
triploid
93
T/F: Allopolyploids have multiple chromosomes that originated from members of the same species
False
94
Allopolyploids are the result of crosses between two different species resulting in
a sterile hybrid offspring that then goes through nondisjunction for every set of chromosomes resulting in a return to fertility
95
Allopolyploidy...
(Select all)
a. is more likely to occur in animals than plants
b. is more likely to occur in plants than animals
c. occurs in organisms that only produce via sexual reproduction
d. is more likely in organisms that lack sex chromosomes
b, d
96
T/F: Orga7nisms that have an odd ploidy level (3X, 5X, 7X etc) are sterile because of an inability to produce gametes with a balanced number of chromosomes
true
97
When organisms that are triploid go through meiosis
(select all)
a. two members of a homologous set may segregate from one member of the homologous set
b. three members of a homologous set may segregate together
c. the segregation of each homologous set is always the same
a, b
98
T/F: As the ploidy level of a cell goes up, the size of the cell goes down.
false
99
T/F: the ploidy level of all tissues is always the same
false
100
ddNTP
(Select all)
a. lack an OH at the 2' carbon
b. lack a nitrogenous base attached to the 1' carbon
c. lack an OH at the 3' carbon
d. lack a phosphate attached to the 5' carbon
a, c
101
If extension of a growing chain of nucleic acid incorporates a ______ extension can not continue
ddNTP
102
T/F: Sequencing reactions produce hundreds of DNA fragments of slightly different lengths because ddNTP are randomly inserted into the chain of nucleic acid during extension.
True
103
You can determine which ddNTP was the last one incorporated into the chain of nucleic acid because
they are conjugated with different fluorescent molecules of different colors
104
T/F: Every cycle through the process of PCR will result in the addition of two new long strands because the original template is always present to serve as the source of these molecules.
True
105
T/F: Two oligonucleotide primers are needed for PCR so that you can use both strands of DNA as a template and amplify in both directions from those flanking positions.
True
106
T/F: At the end of 25 cycles of PCR, most of the DNA strands produced begin at one primer binding location.
True
107
A base substitution that has occurred in one individual but not the other results in..
a SNP
108
T/F: SNP can be detected by annealing a primer immediately upstream of a SNP and testing which nucleotide is added to the primer
True
109
SNP and other molecular markers can be used
(Select all)
a. to clone a gene
b. to make a dense linkage map
c. to predict the occurrence of genetic diseases
d. to breed better crops and domesticated animals
e. develop genetic fingerprints
b, c, d, e
110
T/F: In order for the insert DNA and the vector to be able to bind to each other they should be cut with the same restriction enzyme to produce complementary overhangs.
True
111
In order to fuse the insert and vector together, ____ is used.
ligase
112
Cells that have successfully been transformed with the vector can be identified because
they will be able to grow in the presence of an antibiotic due to the selectable marker on the vector
113
T/F: vectors carrying a DNA insert will be able to express their reporter gene.
false
114
Joe is heterozygous for a dominant mutation that has resulted in the development of kidney cancer. The affected gene is in perfect linkage with a RFLP that produces either a 500 bp (allele 1) or a 300 and 200 bp band (allele 2). His wife does not have the condition and RFLP analysis indicates that she only produces the 500 bp band. their children should monitor the condition of their kidneys if
RFLP analysis indicated the presence of the 500 bp allele and the 300 and 200 bp allele
115
T/F: A clone is an identical genetic copy
true
116
T/F: Cloning of an entire organism involves removing the nucleus from an egg cell and replacing it with the nucleus from an adult somatic cell and stimulating cell division.
true
117
If a population is composed of 200 individuals and the organism is diploid, the gene pool will be composed of a total of _____ copies of any one gene.
400
118
If there are 30 AA individuals, and 20 Aa individuals, and 50 aa individuals in a population, the genotypic frequency of homozygous dominants is...
30%
119
In a population with 30 AA individuals, 20 Aa individuals, and 50 aa individuals, the allelic frequency of the recessive allele is...
60%
120
In the Hardy Weinberg Equation, heterozygotes are represented by....
2pq
121
T/F: If there are only two alleles in a population, the frequency of the dominant and recessive alleles must add up to 1.
true
122
T/F: If you know the frequency of one allele, you can predict the frequency of the alternative allele and predict the genotypic frequencies if the population is in Hardy Weinberg Equilibrium.
true
123
In a population that is in HW Equilibrium, a rare recessive phenotype is observed in 30 out of 1000 individuals. The frequency of the recessive allele must be
i think: 0.173
124
T/F if a population is found to be out of HW equilibrium it indicates that one of the assumptions of Hardy Wein berg has been violated
true
125
T/F: In order for a population to be in HW Equilibrium, the frequency of dominant alleles and recessive alleles must be the same.
false
126
Which of the following statements are true:
(select all)
a. Random mating never occurs
b. No migration in or out of population is required for HW equilibrium
c. A small population is more likely to violate HW equilibrium
d. if the assumptions of HW equilibrium are met, p and q will stay the same and the HW equation may be used to predict genotypic frequencies
b, c, d
