Exam 4
Concerning sporadic cases of retinoblastoma, how many gene mutations are thought to be necessary in the same cell for a tumor to development
2
DNA fingerprinting analyzes microsatellites. Order the steps below in the process of fingerprinting DNA 1) Separate fragment sizes capillary electrophoresis 2)Use PCR to amplify polymorphic regions of DNA 3)Isolate DNA from forensics specimen 4)Visualize product sizes in abundance by florescence
3,2,1,4
Approximate what proportion of your genome is identical to your neighbors
99.9%
An STR marker is
A microsatellite containing short repeat sequences Highly variable in the population
Which of the following would not be considered a polymorphism?
A monomorphic trait.
The probability that a combination of three specific STR alleles such as A5, B2 and C3 will co-occur in an individual in the probability of
A5 x B2 x C3
Briefly describe what is meant by population bottleneck and after the population experiences a bottleneck, what might happen to genetic variation in the survivors
After catastrophe there will be a decrease in population few surviving to reproduce, number of gametes and gene pool will decrease, genetic variation decreases
Which term describing cancer does not fit A) malignant B) benign C) metastatic D) invasive
B
Selection that favors two or more alleles in a more homogeneous environment.
Balancing selection
Name 2 human cancers with a genetic predisposition
Brcal: breast cancer Retinoblastoma Familia melnona
Chronic myelogenous leukemia is associated with a specific chromosome rearrangement. What chromosomes are involved
But, abl kinase
an environmental agent that causes cancer is called
Carcinogen
The relative likelihood that one genotype will contribute to the gene pool of the next generation compared with other genotypes.
Darwinian fitness
An oncogenic form of Ras would have which of the following characteristics
Decrease GTPase activity
What is meant by inbreeding depression and how is the degree of population heterozygosity related to the degree of inbreeding
Decrease in heterozygosity
What type of mutation is frequently associated with loss-of-function tumor suppressor genes?
Deletions
Contrast directional and stabilizing form of Selection
Directional is against one extreme phenotype Stabilizing selecting against both extremes
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
Favors the survival or two or more groups that have different phenotypes.
Disruptive selection
In the CODIS panel of STRs are used for DNA fingerprinting A)There are 13 STR markers used B) Markers are located on different chromosomes C) Markers are highly polymorphic in the population D)Frequency of each marker is dependent upon the population studied E) all the above
E
Which of the following is needed for PCR reaction A) template DNA B) primers C) DNA (tqa) polymerase D) deoxynucleotide triphosphate E) all the above
E
Silencing of tumor suppressor genes by DNA methylation in cancer is an example of what kind of change?
Epigenetic
Slicing of tumor suppressor genes by DNA methylation of promoter regions is an example of what kind of change
Epigenetic
During a PCR, heat is provided to inactivate the polymerase enzyme t/f
F
When PCR products are analyzed by gel electrophoresis the larger PCR amplified fragments of DNA migrate faster and farther than the smaller fragments t/f
F
In Large random meeting population, random genetic drift is usually a significant factor in changing gene frequencies
False
Mutations are regarded as a strong evolutionary mechanism for changing allelic frequencies
False
Inbreeding by itself can change gene allele frequency's
False Genotype frequencies only
The founder affect generally result in an increase in heterozygosity
False Decrease
In directional selection both phenotypic extremes are equally selected against
False To make true: stabilizing
Name two stages in the cell cycle that service points of control
G1/s, G2/m
What term is given to the genetic information carried by all members of the population
Gene pool
How does human papilloma virus 16 induce uncontrolled cell proliferation
HPV 16 inactivate tumor suppressor genes, it's a presses do you want checkpoints E6 E7
5-azacytidine Is an inhibitor of DNA methyltransferase. If it were fed to mice with melanomas due to the loss of P 16 function what was the result be
If there's a decrease in methylation there will be an increase in P 16 and then a decrease in uncontrolled growth This is because you want to do the opposite of what cancer wants to do
When one says that someone has a predisposition to cancer, what genetic circumstances likely exist? Will the person definitely develop cancer in their lifetime.
It would be a inherited dermoid mutation. Since the tumor suppressor genes are recessive it does not guarantee you will have cancer.You will need both recessive genes
____________ are short repetitive sequences that are abundantly interspersed throughout a species' genome and vary in length among different individuals.
Microsatellites
What are the common types of mutations that occur to convert proto-oncogenes to oncogenes?
Missense, Amplifications
If all members of a population have the identical DNA allele, that allele is said to be to be
Monomorphic
Mutation in migration introduce new alleles into population. What is the principal force that shifts allelic frequencies with a large populations
Natural selection
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
A heterogenous environment is typically a ______factor against the fitness of the population
Negative
List the assumptions which pertain under a population any Hardy Weinberg equilibrium
No selection, no migration, no mutation, no genetic drift, random meeting
____________ were discovered in part because some are part of ____________ retrovirus genomes.
Oncogenes, acutely transforming
What is the name of the protein up-regulating by DNA damage, leading to cell cycle arrest? Protein is also known as a guardian of the genome
P53
List factors that contribute to the phenomenon of natural selection
Phenotypic variation, variation inherited, excess population, variation and reproduction success
What Three general mechanisms appear to be involved in the conversion of Proto-oncogenes to oncogenes
Point Mutations, translocations, amplification
Genes which are normal involved in promoting the cell cycle or known as
Proto-oncogenes
Compare and contrast genetic drift versus in breeding
Similar: decrease diversity, decrease Heterozygosity, Decrease fitness Differences: Genetic drift: affects only a small population, allele frequency and genotype changes, increase in one class either homozygous or heterozygous Inbreeding: Affects both large and small population, only changes genotype frequencies, increase in both homozygous classes
Genetic affects that influence the survival of the species are most likely to occur in what
Small populations
Extreme phenotypes are selected against and those that have an intermediate phenotype have the highest fitness value.
Stabilizing selection
Capillary electrophoresis is used to analyze PCR products and DNA fingerprinting t/f
T
Epigenetic's changes in cancer can occur through mutation in DNA modifying proteins like DNA methyltransferase t/f
T
In a PCR, primers are complementary to stretches of DNA with which they anneal t/f
T
Microsatellites (str) and minisatellites (VNTR) are commonly used to fingerprint DNA, since they can be highly variable t/f
T
The DNA (taq) Polymerase used in PCR reactions is derived from the thermophile organism thermos aquaticus that grows in Hot Springs true or false
T
Differentiate among the following types of genes: tumor suppressor Gene, proto-oncogene, oncogene
T: normal, control cell growth, suppresses growth P: normal, promote cell growth that is controlled I:Mutant/activated Gene, promote uncontrolled growth
The degree of relatedness of two members of a Pedigree is calculated using
The coefficient of inbreeding
Which of the following is true regarding a balance polymorphism
The frequency of alleles is not changing over time The homozygous conditions for the alleles is not advantageous to the organism Population occupies the heterogeneous environment The heterozygous condition for the allele is advantageous to the organism
Genetic variation within populations can be measured as the frequency of individuals in a population that heterozygous at a given Lucas, or as a number of different alleles at a Lucas that are present in a gene pool
True
Selection is the differential reproduction of genotypes resulting from there variable fitness
True
When a normal retinoblastoma protein is dephosphorylated, it acts to suppress cell division by binding to an inactivating the E2F transcription factor t/f
True
A loss-of-function mutation in what type of gene can lead to cancer?
Tumor suppressor
Lives two classes of environmental agents which are known to cause cancer
UV radiation, chemicals in smoke, diet, HPV 16
VNTRs are sections of DNA with the following characteristics
Variable numbers of tandem repeats, variable in the population
The number of a specific allele divided by the total number of alleles in the population is known as the ____________ .
allele frequency.
The proteins ________ work together to cause the release of the transcription factor that is bound by the retinoblastoma protein.
cyclin and cyclin-dependent kinase
Mutated forms of the Rb protein
do not bind to E2F thereby promoting uncontrolled cell division.
Different-sized DNA fragments can be separated by
gel electrophoresis.
Conceptually, all of the alleles of every gene in a population make up the ____________ .
gene pool
The number of a specific genotype divided by the total number of individuals within the population is known as the ____________ .
genotype frequency.
In the Polymerase chain reaction, what is the purpose of the initial high temperature. what is the purpose of cooling in the second step
high temperature denatures DNA, cooling allows primers to anneal to DNA
To identify the presence of specific DNA fragments, radiolabeled probes are bound to the fragments in a process termed
hybridization.
A ____________ is a segment of DNA found at a specific site along a chromosome and has properties that enable it to be uniquely recognized using molecular tools such as polymerase chain reaction (PCR) and gel electrophoresis.
molecular marker
A gene that has one allele that is found in 99% of all cases within a population is termed ____________ .
monomorphic
Epigenetics changes frequently occur through
mutations to chromatin modifying proteins
New genetic variations may occur because of (Check all that apply)
new mutations. gene duplications. exon shuffling.
One of the differences between oncogenes and tumor-suppressor genes is that for oncogenes to play a role in tumor development ____________ allele has to be mutated while with tumor-suppressors ____________ alleles have to be silenced or mutated.
one,both
The protein ________ checks for damaged DNA, thereby acting as a "quality control" for the cell.
p53
If an inherited traits displays variation in a population, then the trait is considered ____________ .
polymorphic
Molecular markers may be ____________ ; that is, within a population, they may vary from individual to individual.
polymorphic
To map the distance between molecular markers via crosses, the markers must be
polymorphic.
In population genetics, the term ____________ refers to the observation that many inherited traits display variation within a population.
polymorphism
With regard to sexually reproducing species, a ____________ is a group of individuals of the same species that occupy the same region and can interbreed with one another.
population
A _________ is a normal cellular gene that through a ____________ mutation becomes an oncogene.
proto-oncogene, gain-of-function
In traditional DNA fingerprinting, the DNA is digested by
restriction enzymes.
A polymorphism may involve various types of changes such as a deletion of a significant region of the gene, a duplication of a region, or a change in a single nucleotide. This last phenomenon is called a ____________ polymorphism, which is the smallest type of genetic change that can occur within a given gene and are also the most common.
single nucleotide
Many genes have variations in single nucleotides which are known as ____________ .
single-nucleotide polymorphisms.
Traditional DNA fingerprinting has been superseded by a newer method that analyzes microsatellites instead of VNTRs, uses PCR instead of restriction digestion, and visualizes product sizes by fluorescence instead of radioactivity. t/f
t
If both alleles of a gene from a tumor cell have nonsense mutations that occur very soon after the initiation codon then this gene is probably an example of a ____________ gene.
tumor-suppressor
