Genetics: Exam 3
Which of these are examples of mutagens? -5-Bromouracil -2-Aminopurine -Cytosine -Nitrous acid -Nitrogen mustard -Adenine -Guanine
-5-Bromouracil -2-Aminopurine -Nitrous Acid -Nitrogen Mustard
Which of the following can be categorized under induced mutations? -Depurination -Environmenta -UV light -Ethylmethanesulfate -Natural processes -Deamination -Can result in point mutations -DNA polymerase errors -Radiation
-Environmental -Ethyl methanesulfate -UV light -Radiation -Can result in point mutations
A benign tumor is
A localized growth with a precancerous genetic change
A mutagen is an
Agent that causes mutations
A method for obtaining fetal cells in a sample of the fluid surrounding the fetus is called
Amniocentesis
Match the life stage to the type of screening that would be used to detect a genetic disease: Fetus
Amniocentesis and karyotyping to detect chromosomal abnormalities
Physical mutagens include
Both X-rays and UV light
The region where two chromosome pieces break and re-attach to the other chromosome pieces is called a chromosomal ________________
Breakpoint
Nucleotide excision repair (NER) is the main system used in the repair of
Bulky, helix distorting lesions
In what disease do genetic changes lead to uncontrolled cell growth?
Cancer
A nucleotide deletion in DNA replication
Causes the amino acids downstream from the deletion to be incorrect
An oncogene is typically formed by a _____________ mutation in a normal gene called a ___________________
Gain-of-function; Proto-oncogene
The Ames test assays whether an agent causes
Gene mutations
An individual that has somatic regions that are genotypically different from each other
Genetic mosaic
Cells that give rise to the gametes such as eggs and sperm are called __________ ____________
Germ cells
A silent mutation is a mutation that results in
No change to the amino acid sequence of the polypeptide
If a mutation occurs in the somatic tissue, approximately how many of the gametes will carry the mutation?
None
Some errors create bulky distortions of the double helix. These errors are removed primarily by a DNA repair system called NER, which stands for ______________ _______________ repair
Nucleotide excision
The nucleic acid sequence in mRNA is determined by
Nucleotide sequence in DNA
A mutation that does not change the amino acid sequence of a polypeptide is known as a ____________ mutation
Silent
Match the life stage to the type of screening that would be used to detect a genetic disease: Adult
Test for carrier status if one belongs to a family with a history of a specific disease
Match the life stage to the type of screening that would be used to detect a genetic disease: Newborn Baby
Test for excess phenylalanine demonstrating phenylketonuria (PKU)
Which of these is a common example of widespread genetic screening of newborns to identify certain disorders?
Test for excess phenylalanine indicating phenylketonuria (PKU)
To study the distribution of disease-causing genes, genetic ______________ refers to determining if an individual carries the faulty gene, while genetic ______________ relates to assessing the presence of the gene throughout a population
Testing; Screening
Mutations that occur in a promoter sequence can be divided into two types: _____________ promoter mutations increase the transcription rate, while ______________ promoter mutations decrease it
Up; Down
A breakpoint refers to the region
Where two chromosome pieces break and rejoin with other chromosome pieces
A malignant tumor
-Has cells with cancerous mutations leading to uncontrolled growth -Can form secondary tumors after spreading to other locations -Can invade nearby healthy tissue
Double-strand breaks are typically repaired by which of the following? -Nonhomologous end joining -Nucleotide excision repair -Methyl-directed mismatch repair -Photoreactivation -Homologous recombination repair
-Homologous recombination repair -Nonhomologous end joining
Which of the following can be categorized under spontaneous mutations? -Depurination -Environmental -UV light -Ethyl methanesulfate -Natural processes -Deamination -Can result in point mutations -DNA polymerase errors -Radiation
-Natural processes -DNA polymerase errors -Deamination -Depurination -Can result in point mutations
Alkylating agents may cause mutations by
Disrupting the normal pairing between nucleotides within the DNA
A mutation in a gene may affect the phenotype of the organism in a way that is ____________________ for its survival
Either beneficial, harmful, or neutral
True or False: In nucleotide excision repair, both strands of the DNA are cut and repaired using DNA polymerase and DNA ligase
False
Transletion synthesis refers to
The replication of a template strand that contains DNA damage
If a frameshift mutation causes a stop codon to be inserted into the coding region of a DNA sequence, then ____________________
The resulting protein will be shortened and is often nonfunctional
How does UV light and other nonionizing radiation damage DNA molecules?
They create thymine dimers between adjacent thymines in the DNA chain
Tay-Sachs disease is inherited with an autosomal recessive allele that leads to a defect in the enzyme hexosaminidase A. When cells are collected from patients, cells with different genotypes exhibit different amounts of enzymatic activity. Rank the amount of enzymatic activity that would be detected in a biochemical assay on cells from patients of these genotypes, with the genotype producing the LEAST amount of enzymatic activity on top
1. Homozygous recessive 2. Heterozygous 3. Homozygous dominant
Match the DNA sequence with the possible consequence of a mutation in that sequence: Splice Site
May alter the ability of pre-mRNA to be properly spliced
The process of converting a normal cell into a malignant cancer cell is called
Transformation
The synthesis of DNA over a template strand that harbors some type of DNA damage is called _______________ ________________
Translesion synthesis
Mutations can be caused in two main ways: 1. _______________ mutations are the result of natural biological or chemical processes; and 2. ________________ mutations are produced by environmental agents
1. Spontaneous 2. Induced
What is the inheritance pattern when the trait occurs with the same frequency in both sexes and two unaffected heterozygotes have, on average, 25% affected children?
Autosomal recessive
During the normal course of DNA replication, the addition of a nucleotide that does not obey the AT/CG rule of base pairing creates a
Base pair mismatch
Base analogs induce mutations by
Being incorporated instead of normal bases during replication
Which of these tests is used to evaluate the mutagenicity of an agent? -The Pasteur test -The Ames test -The Pheonol coefficient test -The Kirby-Bauer test
The Ames test
The term germ line is used to describe
The cells that produce sperm and egg
True or False: Chemical agents can cause mutations by inducing methylation of guanine residues in DNA
True
The wild type genotype or phenotype is the one that is
Typically found in nature
Amniocentesis is a procedure for
Obtaining fetal cells in a sample from the fluid surrounding the fetus
The enzyme that can recognize thymine dimers and split them is called _______________
Photolyase
A ___________ mutation refers to a mutation in which just one base is changed within the DNA sequence
Point
A change in a single base pair in the genetic material is known as a ____________ mutation
Point
Reactive oxygen species (ROS) are
Products of oxygen metabolism in all aerobic organisms
Match the DNA sequence with the possible consequence of a mutation in that sequence: Operator
May disrupt the ability of the gene to be properly regulated
Match the DNA sequence with the possible consequence of a mutation in that sequence: Promoter
May increase or decrease the rate of transcription
Cancer cells can migrate to other parts of the body and cause secondary tumors. This property is called ________________
Metastasis
The ability of cancer cells to migrate to other parts of the body where they can cause secondary tumors is referred to as
Metastasis
An agent that can cause DNA structure and cause mutations is known as a _______________
Mutagen
An oncogene is formed when a proto-oncogene gains a
Mutation that causes its expression to be abnormally active
A second mutation that occurs in a different site than the firsts mutation, and which converts the mutant back to the wild-type phenotype, is best referred to as a ___________________ mutation
Suppressor
Bottleneck Effect
-Loss of alleles can occur due to genetic drift -Population size reduced to a few individuals -An example is the Cheetah population -Results in loss of genetic diversity -Small population increases probability of losing alleles -Usually due to catastrophic event
Which of the following statements about promoter mutations is true? -Up promoter mutations cause the promoter sequence to be more like the consensus sequence -Down promoter mutations occur in the 3'-UTR of the gene -Down promoter mutations decrease the affinity of transcription factors to the promoter -Up promoter mutations occur in the coding sequence of the gene
-Up promoter mutations cause the promoter sequence to be more like the consensus sequence -Down promoter mutations decrease the affinity of transcription factors to the promoter
You have a population in Hardy-Weinberg equilibrium for the M and N alleles. These alleles are codominant. The allele frequency of M is .4. What is the frequency of heterozygotes in the population?
.48
A couple has two children, one normal and one with CF. What is the probability that the normal child is a carrier?
2/3
The Hardy-Weinberg equilibrium is a mathematical expression, which predicts that, when certain requirements are met, the allele and genotype frequencies of a gene in a popuation
Do not change over the course of many generations
True or False: The phenotypic effects of a mutation are either detrimental or neutral
False
The number of a specific genotype divided by the total number of individuals within the population is known as the _____________________________
Genotypic frequency
Cells that give rise to the gametes
Germ line cells
Genome maintenance includes cellular mechanisms that prevent which two processes?
Mutation; Division of survival of mutant cells
Which of the following are examples of base pair mismatches? -Cytosine on parent strand and Adenine on daughter strand -Adenine on parent strand and Cytosine on daughter strand -Adenine on parent strand and Thymine on daughter strand -Cytosine on parent strand and Thymine on daughter strand -Cytosine on parent strand and Guanine on daughter strand
-Cytosine on parent strand and Adenine on daughter strand -Adenine on parent strand and Cytosine on daughter strand -Cytosine on parent strand and Thymine on daughter strand
Characteristics of a genetic disease
-Disease not spread to others in the same environment -Different populations may have different disease rates -Disease may develop at characteristic age -Human disease resembles animal genetic disease -Correlation between disease and known mutation -Disease more likely to occur in relatives than general population -Identical twins share disease more often than non-identical twins
Not a characteristic of a genetic disease
-Disease spread to others in same environment -Disease affects many different age groups -Bacterium causes the same disease in an animal -Use of an antibiotic cures disease
Founder Effect
-Loss of alleles can occur due to genetic drift -Population started by a few members of another population -An example would be the Old Order Amish -Results in loss of genetic diversity -Small population increases probability of losing alleles -Usually due to geographical event
What features demonstrate that this syndrome is caused by an autosomal dominant mutation?
-Males are affected as often as females -Individuals that are affected have at least one parent that is affected
Choose all that is required for gene flow to occur -Migrants must be fertile and pass their genes to the next generation -Individuals must migrate from one population to another -At least some of the migrants must be female -Migrants must have reproduced at least once in the donor population
-Migrants must be fertile and pass their genes to the next generation -Individuals must migrate from one population to another
What are the common types of mutations that occur to convert proto-oncogenes to oncogenes?
-Missense -Amplifications
Choose two of the most important results of the founder effect on the newly founded population -All allele frequencies in the founding population are very small (close to zero) -The founding population typically has less genetic diversity than the original population -The founding populations usually has a higher rate of mutation (many new alleles appear) -The founding population typically has very different allele frequencies from those of the original population
-The founding population typically has less genetic diversity than the original population -The founding population typically has very different allele frequencies from those of the original population
You have a population where you know people's MN blood types. (M and N are co-dominant). 50 people are type MM, 30 are type MN, and 10 are type NN. What is the allele frequency of M?
.72
A young man knows that his grandfather had Huntington disease. However, his father passed away at the age of 26 without ever being tested or showing signs of HD. What is the probability that this young man will develop HD when he is older?
1/4
A phenotypically normal individual with a sibling that has cystic fibrosis marries a known carrier of the CF mutation. If they have a child, what is the probability that their child will develop cystic fibrosis?
1/6
Repetitive sequences are composed of a certain sequence that is repeated many times throughout the genome of a species. What is the typical size of the sequence that is being repeated?
A few to a few thousand base pairs
Which of the following correctly defines a population of sexually reproducing species for the purposes of population genetics?
A group of individuals that occupy the same area and can interbreed with each other
Select the example of bottleneck effect
A landslide occurs, killing the majority of a population of mountain goats
The Old Order Amish of Lancaster County, Pennsylvania were founded by only three couples in 1700. Currently, this human population is made of thousands of people. Which of the following is a characteristic of this population nowadays, that is a consequence of the founder effect in this population's history?
A much higher frequency of certain very rare human genetic diseases
Which of the following accurately describes the genetic changes leading to malignancy
A series of successive gene changes occurs, involving oncogene activation and inactivation of tumor-suppressor genes
In a certain population at Hardy-Weinberg equilibrium, the frequencies of two alleles A and a are equal. What is the frequency of each genotype in the population?
AA: .25 Aa: .5 aa: .25
Consider a population of cheetahs, inhabiting a protected area in Africa. In 2012, there were 112 cheetahs in this population. During that year, 60 of those animals reproduced and 48 new cubs were born. What constitutes the gene pool of the new generation made of those 48 new cubs?
All of the alleles of all of the genes that were passed from the parents to the 48 new cubs
The number of a specific allele divided by the total number of alleles in a population is known as the ___________________________
Allele frequency
A mutation in one gene that reverses the effects of a mutation in a different gene is _______________
An intergenic suppressor
Certain compounds have a structure similar to normal DNA bases and can be incorporated into daughter strands during DNA replication. These compounds are called base _________________
Analogs
The loss of a chromosome carrying a tumor suppressor gene is an example of a way of losing the function of this gene through
Aneuploidy
For random mating to occur, individuals must choose their mates irrespective of their genotype/phenotype. When this condition is violated, non-random mating is occurring, also known as _________________ mating
Assortative
What is the inheritance pattern when a trait occurs with the same frequence in both sexes and an affected offspring can have two unaffected parents?
Autosomal recessive
In _________________ selection, natural selection favors the maintenance of two or more alleles in a population. An example of that is the phenomenon of heterozygote advantage
Balancing
In certain populations, natural selection can favor the maintenance of 2 or more alleles in a population. An example of this is
Balancing selection
Selection that favors two or more alleles in a more homogeneous environment
Balancing selection
During the initial stage of cancer development, cells with a precancerous genetic change form a
Benign growth
Horizontal gene transfer is the transfer of DNA
Between different genomes
The ______________ effect is observed when a population's size is dramatically reduced due to natural events, such as earthquakes and flood, or due to human destruction of habitat
Bottleneck
Suppose a disease-causing allele shows autosomal inheritance. How could a carrier of this disease causing allele be identified?
Carriers often show reduced activity for the enzyme encoded by the allele
Select the example of microevolution
Change in allele frequency following a natural disaster
Ewing's sarcoma is a cancer of the bone and soft tissues where a new transcription factor is produced from the fusion of the coding regions of two different proteins. The ews gene of chromosome 22 is joined to the fili1 gene of chromosome 11. Neither the ews nor the fil1 gene individually cause cancer. this change from proto-oncogene to oncogene occurred as a result of
Chromosomal translocation
Most cancer cells are descendants of an original cell that acquired genetic changes. Therefore, cancerous growths are considered to be _____________________ in origin
Clonal
DNA microarrays can be used to
Compare gene activity in cancer cells and normal cells
In cancer biology, transformation is the process of
Converting a normal cell into a malignant cell
If a comparison of two variables shows that they increase together, a positive ____________ is demonstrated and, if the results are statistically significant, a true _____________ between the variables is suggest
Correlation; Association
Which change from proto-oncogene to oncogene occurred by chromosomal translocation?
Creation of a new transcription factor through the fusion of chromosomal segments from two different chromosomes
The proteins __________________ work together to cause the release of the transcription factor that is bound by the retinoplastoma protein
Cyclin and cyclin-dependent kinase
Human individuals can be characterized by analyzing the presence and sizes of repetitive sequences in their DNA, a technique known as
DNA fingerprinting
Clinical improvement in leukemia patients has been observed when providing drugs that inhibit the enzyme
DNA methyltransferase
A method that can identify genes that are active in cancer cells but inactive in normal cells is
DNA microarray analysis
Which of the following synthesizes the new DNA strand? -DNA ligase -DNA polymerase -DNA helicase -UvrA-UvrB trimer
DNA polymerase
The relative (compared to other genotypes) likelihood that a genotype will contribute its alleles to the next generation is known as ______________ _______________
Darwinian fitness
The relative likelihood that one genotype will contribute to the gene pool of the next generation compared with other genotypes
Darwinian fitness
Nitrous acid is a mutagen that acts via that process of
Deamination
The mutagen nitrous acid changes cytosine to uracil, and adenine to hypoxanthine, through the process of ________________
Deamination
What type of mutation is frequently associated with loss-of-function tumor suppressor genes?
Deletions
The removal of a purine from DNA is called ___________________
Depurination
Mutations that remove an adenine or guanine from the DNA are known as
Depurinations
The tumor-suppressor gene p53 has a significant role in
Detecting DNA damage in a cell
Which of these represents the correct order of steps during a typical DNA repair system?
Detection-->Removal-->Replication
In _________________ selection, individuals at one extreme of a phenotypic distribution are more likely to survive and reproduce in a particular environment
Directional
Sometimes individuals at one extreme of a phenotypic distribution are favored in a particular environment, for example, selection will strongly favor insects that have very high resistance to an insecticide. In such cases, the type of selection that operates is
Directional Selection
A type of natural selection that favors individuals at one extreme of a phenotypic distribution that are more likely to survive and reproduce in a particular environment
Directional selection
If a high chi-square value is obtained when comparing observed and expected genotypes in a population, we can state that the population is in ________________
Disequilibrium
Favors the survival of two or more groups that have different phenotypes
Disruptive selection
Which of the following types of selection creates two phenotypic classes from a single original distribution?
Disruptive selection
Which type of selection is also known as diversifying selection because it tends to favor the survival of two or more different phenotypes in a heterogenous environment?
Disruptive selection
Mutated forms of the Rb protein
Do not bind to the E2F thereby promoting uncontrolled cell division
The term genetic _____________ refers to any random change in the frequencies of alleles in a population
Drift
Vertical gene transfer is the transfer of DNA
During normal cell division
A population that has experienced a bottleneck is highly susceptible to genetic drift
During the initial bottleneck and during the generations following the bottleneck when the population size is small
Silencing of tumor suppressor genes by DNA methylation in cancer is an example of what kind of change?
Epigenetic
The Hardy-Weinberg equilibrium is used as a null hypothesis, i.e., if a population is in Hardy-Weinberg equilibrium, then
Evolutionary change is not occurring in this population
Sometimes populations become susceptible to genetic drift via the __________________ effect. This happens when a small group of individuals separates from a larger population and migrates to a different site, where it estabilishes a colony
Founder
Different-sized DNA fragments can be separated by
Gel electrophoresis
When individuals migrate, alleles can be transferred from one population to another population. This is commonly referred to as ____________________ _____________________
Gene flow
The ___________________ of a population consists of all of the alleles of every gene in all of the individuals of that population
Gene pool
Mutation that can be passed onto offspring
Germ line mutation
A signaling molecule that can promote division of cells throughout the body of a multicellular organism is called a
Growth factor
A cancer cell is a cell that
Has accumulated genetic changes that allow it to grow unconditionally
An individual who is heterozygous for a defect in a tumor-suppressor gene
Has inherited an increased susceptibility to develop cancer
Most individuals who are born with an inherited form of cancer susceptibility are
Heterozygous for a defect in a tumor-suppressor gene
Suppose a chi-square analysis is performed to test whether the observed genotypes in a population are consistent with the predictions of Hardy-Weinberg equilibrium. Which type of chi-square value will be obtained if a population is in disequilibrium?
High
The development of cancer could be promoted if an abnormally __________ level of methylation occurred at CpG islands near the start site of a tumor-suppressor gene
High
The two main mechanisms used to repair DNA double-strand breaks are __________________ recombination and ____________________ end joining
Homologous; Nonhomologous
During ________________ gene transfer, genetic material from a donor organism is incorporated into a recipient organism which is not the donor's offspring
Horizontal
The transfer of genetic material from one species to another (regardless of the exact mechanism) is called
Horizontal gene transfer
Which of the following is an epigenetic change that would likely lead to cancer?
Hypermethylation inhibits the expression of a tumor suppressor gene
Molecular profiling is
Identification of the genes that play a role in the development of a specific type of cancer
The mutation rate is commonly expressed as the number of new mutations
In a given gene per cell generation
Genetic testing is used to determine whether an _________________ has a disease-causing gene, while genetic screening is used to determine how frequently the gene is found in a ___________________
Individual; Population
What is the effect of a suppressor mutation?
It suppresses the phenotypic effect of another mutation
Cellular mechanisms that prevent mutations from occurring and/or prevent mutant cells from dividing or surviving are referred to as genome
Maintenance
A series of genetic changes, involving oncogene activation and tumor-suppressor gene inactivation, leads to
Malignancy
Which type of growth has cells that can invade other tissues and migrate to other areas of the body to form secondary tumors?
Malignant growth
Match the DNA sequence with the possible consequence of a mutation in that sequence: UTR
May alter the ability of mRNA to be translated; May alter mRNA stability
Alkylating agents covalently attach ________________ or _______________ groups to DNA bases, and thus dirupt their normal base pairing properties
Methyl; Ethyl
Mutations in DNA ____________, an enzyme catalyzing changes that inactivate genes, have been associated with the development of acute myeloid leukemia
Methyltransferase
To potentially reverse the inactivation of tumor-suppressor genes, researchers are developing potential cancer treatments that involve inhibition of the enzyme DNA
Methyltransferase
The change in a population's gene pool from one generation to the next is known as
Microevolution
The process of identifying genes that play a role in the development of a specific type of cancer is called
Molecular profiling
A gene that has one allele that is found in 99% of all cases within a population is termed __________________
Monomorphic
A ____________________ is any change in the DNA of an organism, for example, a change in DNA sequence or the structure and number of chromosomes
Mutation
The probability that a gene will be altered by a new mutation is referred to as the ___________ ___________
Mutation rate
The theory that states that the conditions found in nature result in the selective survival and reproduction of individuals whose characteristics make them better adapted to their environment
Natural Selection
The mechanism of evolution through _________________ _______________ states that those individuals better adapted to their environment are more likely to survive and reproduce
Natural selection
The mechanism of evolution through _________________ ________________ was proposed by Charles Darwin and Russel Wallace in the 1850s
Natural selection
A gene that promotes cancer is called an
Oncogene
A mutant gene that is overexpressed and contributes to the formation of cancer is termed an ________________
Oncogene
For the inherited tendency to develop retinoblastoma in the first few years of life, which correctly describes inactivation of the rb tumor-suppressor alleles by the "two-hit" model?
One allele is inactivated prior to birth, the other becomes inactivated early in life
Cancerous growth are clonal in origin because cancer cells
Originate from a single cell that has accumulated genetic changes during cell division
Using information about a patient's genotype along with other clinical data to determine the best course of treatment is called
Personalized medicine
The study of genetic variations that cause different responses to drugs is called
Pharmacogenetics
A _____________ is a change in a single base pair within the DNA
Point mutation
If an inherited trait displays variation in a population, the the trait is considered _________________
Polymorphic
In genetics, a ____________________ of a sexually reproducing species consists of a group of individuals of that species, which occupy the same region, and can successfully interbreed with each other
Population
If an increase in DNA methylation of a gene is associated with an increase in severity of a specific disease, these two variables show a
Positive correlation
In ____________________ assortive mating, individuals tend to choose mates with similar phenotypes. In _________________ assortive mating, individuals tend to choose mates with dissimilar phenotypes
Positive; Negative
A tumor-suppressor gene codes for a protein that normally
Prevents cancerous growth
In DNA _______________, an individual is characterized based on the repetitive sequences in his or her genome
Profiling
Products of oxygen metabolism, such as hydrogen peroxide, superoxide, and hydroxyl radical, are collectively called ____________ ___________ species
Reactive Oxygen
Most eukaryotic species contain short sequences, typically a few base pairs to a few thousand base pairs long, that are repeated many times throughout the genome. The general name for these types of sequences is
Repetitive sequences
In traditional DNA fingerprinting, the DNA is digested by
Restriction enzymes
Mutations occur when the DNA of an organism changes. Changes often happen in gene ______________, but may also involve the structure and number of chromosomes
Sequences
A growth factor is a
Signaling molecule that can stimulate cells throughout the organism's body to divide
Many genes have variations in single nucleotides which are known as _____________________________________
Single-nucleotide polymorphisms
All cells of the body excluding the gametes or cells that can give rise to the gametes
Somatic cells
A mutation that cannot be passed onto the offspring
Somatic mutation
Errors in DNA replication are examples of _____________ mutations, while mutations caused by ultraviolet light are _______________ mutations
Spontaneous; Induced
_________________ selection acts on quantitative traits determined by multiple genes. In this type of selection, individuals with intermediate phenotypes have higher fitness and are selected for, while extreme phenotypes are selected against
Stabilizing
Extreme phenotypes are selected against those that have an intermediate phenotype have the highest fitness value
Stabilizing selection
Which type of selection tends to select against extreme phenotypes for a quantitative trait, because individuals with intermediate phenotypes have the highest relative fitness values?
Stabilizing selection
Pharmacogenetics is the
Study of genetic variations that cause differing responses to drugs
A scientist is studying two populations of the same species of birds-one in Michigan, and one in Montana. Both populations are relatively large (with more than 10,000 individuals each). However, the Michigan population has a much lower genetic diversity than the Montana population. Which of the two populations is most likely to have experienced a bottle neck and which of the two populations is currently more susceptible to genetic drift?
The Michigan population likely experienced a bottleneck in the past. Both populations are equally susceptible to genetic drift
Consider a population and a gene that has two alleles in this population, designated as P and p. If you divide the number of all the copies of the p allele in the population by the total number of copies of both alleles (P and p) in the population, you will calculate
The allele frequency of the p allele
A healthy population can become highly susceptible to genetic drift if its size is dramatically reduced due to natural phenomena, such as an earthquakes, or droughts. This is known as
The bottleneck effect
Microevolution is best described as
The change in a population's gene pool from generation to generation
Aneuploidy is a mechanism for losing the function of a tumor-suppressor protein because
The chromosome carrying the tumor-suppressor gene can be lost from the cell
A group of individuals from a larger population can migrate to a new area and establish a colony, which will be highly susceptible to genetic drift. This is known as
The founder effect
How is the allele frequency of a population calculated?
The number of copies of the allele in the population is divided by the total number of all the alleles for the same gene in the population
For the non-inherited development of retinoblastoma, which correctly describes the inactivation of the rb tummor-suppressor alleles by the "two-hit" model?
The person is born with two active copies of the rb allele; separate mutation events are required to inactivate each of these alleles
Genetic drift is
The random change of allele frequencies in a population
Which of the following is the best definition of Darwinian fitness as it relates to population genetics?
The relative (compared to other genotypes) likelihood that a genotype will contribute alleles to the next generation
The human population known as the Old Order Amish of Lancaster County exhibits an unusually high frequency of the genetic disease Ellis-van Creveld syndrome. What explains that observation?
This population was founded by a very small group of people
The phenomenon in which a repeated sequence of three bases increases in number generation after generation is called ______________ __________ __________
Trinucleotide repeat expansion
True or False: Most DNA repair systems involve three major steps: detection of the error, removal of the abnormality, and its replacement with normal DNA
True
True or False: The addition of a single nucleotide to the DNA sequence causes a frameshift mutation
True
A loss-of-function mutation in what type of gene can lead to cancer?
Tumor suppressor
A gene that codes for a protein that prevents cancerous growth is called a
Tumor-suppressor gene
In disruptive selection
Two or more alleles are maintained in a heterogenous environment
Personalised medicine is the
Use of information about a patient's genotype and other clinical data to select an individualized treatment
A founding population usually has lower genetic diversity than the original population it came from. For those alleles that are shared by the two populations, how are the allele frequencies different (or similar)?
Usually, the allele frequencies in the founding population are very different from those of the original population
Trinucleotide repeat expansions are repeated sequences of three bases
Which increase generation after generation
In a natural population, a __________________-_____________ genotype is the most common one
Wild-type
A couple has four children, two sons and two daughters. One son has hemophilia and the other does not. One daughter has hemophilia and the other is a carrier. What were the genotypes of the mother and the father?
XHXh-A and Xh-A Y
Mutations in the genes for enzymes that catalyze the additions or removals of _____________, _____________, or ______________ on histones have been implicated in the development of cancer
acetyl, methyl, phosphate
The protein _________ checks for damaged DNA, thereby acting as a "quality control" for the cell
p53
Which gene plays a significant role in detecting DNA damage in a cell?
p53
A _______________ is a normal cellular gene that through a _________________ mutation becomes an oncogene
proto-oncogene; gain-of-function
