genetics exam 2
(ch14) DNA that contains instructions for two or more structure genes produces monocistronic mRNA a) true b) false
a
(ch14) If CAP could not bind to its CAP site, then what would be result? assume lactose is present in each scenario. a) transcription would be difficult to repress in the presence of glucose b) transcription would be difficult to activate in the absence of glucose c) transcription would be difficult to activate in the presence of glucose
a
(ch14) Operons that code for catabolic enzyme systems are typically regulated by repressors a) true b) false
a
(ch14) The regulation of the CAP complex using cAMP is an example of inducible genetic regulation. a) true b) false
a
(ch14) constitutive genes are those that have constant levels of expression a) true b) false
a
(ch26) If the allele frequency of the dominant allele is 0.4, what value is used for the term p2 in the equation? a) 0.4 b) o.2 c) o.16 d) 16
a
(ch15) Which of the following is the most likely location of an insulator sequence? a) between two genes b) in the middle of a gene c) within an intron d) at the end of a gene e) at the beginning of a gene
a) between two genes
(ch15) DNA that contains actively transcribed gene would most likely contain chromatin in the closed configuration a) false b) true
a) false
(ch15) Insulators exert their effect one gene expression through histone acetyltranserase, histone deacetylase, and RNA polymerase. a) false b) true
a) false
(ch26) Migration of a random few individuals from one population to new area to establish a new population is an example of ___. a) founder effect b) bottleneck effect c) mutation d) selection
a) founder effect
(Ch16) What gene(s) is/are encoded in the Xic? a) Xie b) Xist c) Tsix d) both Tsix and Xist genes are in the Xic region
b
(ch14) Operons that code for anabolic enzyme systems are typically regulated by inducers. a) true b) false
b
(ch16) What are some disease associated with imprinting? a) LHON b) Angelman Syndrome c) all of the answers are correct d) Alzheimer's Disease
b
(ch26) A group of individuals from the same species that can interbreed with one another is the definition of a ___. a) kingdom b) population c) race d) community e) species
b
(ch14) A deletion in an operon removes the terminator. How will that affect the transcript that is produced from the operon? a) the transcript will be produced and normal in length b) the transcript will not be produced c) the transcript will be produced, but shorter than normal d) the transcript will be produced, but longer than normal
c
(ch14) Enzymes involved in metabolism are most likely regulated via ___. a) none of the answers are correct b) feedback inhibition c) methylation d) acetylation
c
(ch14) What is the gene responsible for attenuation in the trp operon? a) trpL b) trpC c) trpR d) trpD
c
(ch14) Which of the following is an example of post translational regulation in prokaryotes? a) altering the structure of the mRNA b) sterically blocking the ribosome c) incorporation of antisense RNa d) phosphorylation of an enzyme
c
(ch14) in a particular E. coli strain, a mutation in the thiMD operon results in improper formation of the stem loop secondary structure making it impossible to bind TPP. There are two enzymes encoded by the thiMD operon. How many of the enzymes encoded in the thiMD operon are translated? a) zero b) one c) two d) tree
c
(ch16) the most likely explanation for the phenomenon where a protein may be found in different sub-cellular locations in different cells is a) RNA interference b) stabilization of the mRNA transcript c) alternative splicing d) transport of mRNA from the nucleus to the cytoplasm
c
(ch27) After calculating a coefficient you discovered that the value is not significant at the 5% level. What can be done to produce a significant different? a) nothing , the value will remain the same regardless of sample size b) decrease the sample size c) increase the same size
c
(ch26) The prevalence of the allele for sickle cell anemia in some populations is an example of? a) inverted selection b) nonrandom mating c) balancing section d) heterogeneous environments e) non-Darwinian selection
c) balancing section
(ch15) Histone acetyltransferases are directly involved in which of the following? a) insertion of variant histone proteins b) termination of gene expression c) chemical modification of histones d) movement of nucleosomes
c) chemical modification of histones
(ch26) which type of selection would lead to two distinct phenotypes? a) phenotype selection b) stabilizing section c) disruptive selection d) directional selection e) fitness selection
c) disruptive selection
(ch15) Which of the following structure motifs promotes dimerization? a) Zinc finger b) Helix-loop-helix c) leucine zipper d) helix-turn-helix
c) leucine zipper
(ch16) Most imprinted genes are silenced. What is one exception to this rule? a) SNRPN b) UBE3A c) lgf-2 d) H19
c) lgf-2
(ch27) What is true concerning a quantitative trait? a) the frequency distribution of the trait will have an asymmetrical shape b) the phenotypic variation for the trait falls into two to tree classes c) the phenotypic variation for the trait is continuous d) individuals fall into distinct classes for comparison
c) the phenotypic variation for the trait is continuous
(ch14) How many promoters are in an operon a) 2 b) 3 c) it depends on how many are present in the operon d) 1
d
(ch14) If a bacteria is placed in an environment that contains both glucose and lactose, the regulation of the lac operon will allow which nutrient to be processed first a) neither will be processed in this environment b) both will be processed equally c) lactose d) glucose
d
(ch16) Which of the following is an example of epigenetic inheritance? a) inheritance of flower color as studied by Mendel b) Snail shell twist patterns c) Leaf coloration based on mitochondrial inheritance d) expression of the lgf-2 gene based on methylation of the ICR and DMR regions
d
(ch26) A SNP would best be described as ___. a) a gene that comes in multiple different alleles b) a balanced polymorphism system c) the most likely mutation to affect protein function d) a single nucleotide difference between two DNA sequences
d
A common way of studying methylation in cells is to sequence DNA samples before and after modification with sodium bisulfite. The sodium bisulfite deaminates Cytosine residues, generating Uracil residues, therefore resulting in change in the sequence as compared to the non-modified DNA. Sodium bisulfite does not react with 5-methylcytosine so there will be no change in the sequence of those modified bases. When tumors are sequenced to study methylation patterns and epigenetic control, what would be the best control for sequencing using this technique? a) Non-cancerous tissue DNA from a different individual but from the same organ b) a combination of DNA from liver, brain and muscle from the same individual that has the cancer c) Liver DNA from the same individual that the caner sample is from d) DNA from non-cancerous tissue from the same individual's organ as the cancer
d
(ch15) Which of the following would also work as an enhancer for the following bi-directional enhancer? 5' GTTC 3' 3'CAAG 5' a) 5' CTTC 3' 3' GAAG 5' b) 5' CAAG 3' 3' GTTC 5' c) 5' CTTG 3' 3' GAAC 5' d) 5' GAAC 3' 3' CTTG 5'
d) 5' GAAC 3' 3' CTTG 5'
(ch15) What basal transcription factor is most often affected by regulatory transcription factors? a) TFIIE b) TFIIF c) TFIIB d) TFIID
d) TFIID
What gene is most responsible for X-inactivation? a) Tsix b) Xce c) Xic d) Xist
d) Xist
(ch16) a modification that occurs to a nuclear that alters gene expression, but not permanently, is called ___ inheritance. a) extranuclear b) cytoplasmic c) maternal effect d) nuclear e) epigenetic
a
(ch27) Polygenic inheritance may result in a continuum of phenotypes because a) there is a low environmental effect b) there is a high environmental effect c) the genes that are involved an be considered to be co-dominant d) the alleles for each gene are either completely dominant or recessive
a
(ch26) The coefficient of inbreeding (F) tells us what about an individual? a) the probability that they are homozygous due to inheritance from a common ancestor b) their genotype c) the probability of obtaining a certain allele from the gene pool
a) the probability that they are homozygous due to inheritance from a common ancestor
(ch15) Steroid hormones are an example of an effector which regulates regulatory transcription factor activity a) true b) false
a) true
(ch15) The activity of some transcription factors can be regulated by modifications. a) true b) false
a) true
(ch27) Traits that fall into discrete categories are called continuous traits a) true b) false
b) false
(ch27) a population that is homozygous for a given allele is called polymorphic. a) true b) false
b) false
(ch26) Genetic drift has a greater influence on ___ populations a) large b) small c) it affects both equally
b) small
(ch26) In a given population of drosophila, curly wings (c) is recessive to the wild-type condition of strait wings (c+). You isolate a population of 35 curly winged flies, 70 flies that are heterozygous for straight wings and 45 that are homozygous for straight wings. what is the total number of alleles in the gene pool? a) 140 b) 230 c) 2 d) 150 e) 300
e) 300
(ch15) A particular cell contains all of the standard histones but lacks several histone variants. Which of the following MAY be true of this cell? a) The cell will be completely unable to remodel its chromatin b) the cell will be unable to express any of its gene at all. c) the cell will have an enhanced ability to chemically modify its histones d) the cell will not be able to divide e) the cell will express different sets of genes than other cells in the same organism
e) the cell will express different sets of genes than other cells in the same organism
(ch15) When cortisol binds to the glucocorticoid receptor, HSP90 is released. a) true b) false
a) true
(ch15) cAMP is known as a second messenger since the pathway is first activated by a extracellular signaling molecule. a) true b) false
a) true
(ch15) housekeeping genes are unmethylated and active in most cells a) true b) false
a) true
(ch14) Allosteric regulation is accomplished by a) a large protein that blocks an enzyme's active site b) a small molecule that fits into a site on the enzyme that is not the active site c) a small molecule that fits into an enzyme's active site d) a small molecule that covalently modifies a site on the enzyme that is not the active site
b) a small molecule that fits into a site on the enzyme that is not the active site
(ch27) Heritability may be calculated as which of the following? a) genetic variance divided by environmental variance b) the total variance minus environmental variance c) total variance minus genetic variance d) genetic variance divided by total variance
d) genetic variance divided by total variance
(ch15) What activates CREB? a) lowering of cAMP concentration b) binding of cAMP c) binding to GRE d) phosphorylation e) dimerization
d) phosphorylation
(ch26) which of the following is not true concerning a population in equilibrium according to the Hardy-Weinberg rule? a) there is no mutation in the populations b) the population size is very large c) there is no migration into or out of the population d) selection is favoring the dominant allele e) individuals of the population mate randomly
d) selection is favoring the dominant allele
(ch16) The differentially methylated region (DMR) is associated with which of the following? a) genomic imprinting b) maternal inheritance c) extra nuclear inheritance d) all of the answers are correct e) X-inactivation
a) genomic imprinting
(ch27) Many organisms used in modern agriculture are a result of artificial selection. a) true b) false
a) true
(ch27) The amount of phenotype variation in a group that is due to genetic variation is called heritability. a) true b) false
a) true
(ch15) CpG islands are associated with which of the following? a) nucleosome location b) DNA methylation c) cAMP pathway d) steroid hormone activity
b) DNA methylation
(ch27) Eye color in Drosophila is an example of a) discontinuous, quantitative trait b) discontinuous, non-quantitative trait c) continuous, quantitative trait d) continuous, non-quantitative trait
b) discontinuous, non-quantitative trait
(ch15) Methylation of DNA bases is one way that regulatory transcription factors may influence gene expression a) true b) false
b) false
(ch27) The sum of all of the values for a trait, divide by the total number of individuals, is called the standard deviation. a) true b) false
b) false
(ch27) Inbreeding reduces which of the following variances to near zero? a) Neither variance b) genetic variance c) both variance d) environmental variance
b) genetic variance
(ch27) When analyzing two variables, the strength of the association between the variables is called the ___ a) covariance b) variance c) standard deviation d) correlation coefficient
d) correlation coefficient
(ch16) What is the difference between the trithorax (TrxG) and polycomb (PcG) complexes of proteins? a) TrxG complex proteins activate gene expression by methylation lysine 4 on H3, while PcG complex proteins repress gene expression by methylating lysine 27 on H3 b) TrxG proteins methylate lysine 27 on histone H3 while PcG complexes methylate lysine on H3 c) methylation of lysine at position 4 on H3 in silencing of gene expression d) methylation of H3 on lysine 27 can result in activation of transcription
a
(ch27) the square root of the variance is called ___. a) standard deviation b) covariance c) standard error d) mean
a) standard deviation
(ch15) in ChlP-Seq, the DNA fragments to be sequenced are around 150 bp in length. What does this size of DNA represent? a) the amount of DNA wrapped around a nucleosome b) the average length of a gene c) the average distance between nucleosomes d) the amount of DNA between nucleosomes e) the length of a promoter
a) the amount of DNA wrapped around a nucleosome
(ch26) In this equation p^2 + 2pq + q^2 = 1, what does 2pq represent? a) the genotype frequency of heterozygous individuals b) the genotype frequency of homozygous dominant individuals c) the sum of phenotype frequencies in the population d) the genotype frequency of homozygous recessive individuals
a) the genotype frequency of heterozygous individuals
(ch16) How many Barr bodies would an individual a XXY genotype possess? a) o b) 1 c) 2 d) none of the answer are correct
b) 1
(ch14) What stem-loop conformations favor attenuation? a) 1-2 and 2-3 b) 1-2 and 3-4 c) 2-3 d) 1-2
b) 1-2 and 3-4
(ch27) After several generations of artificial selective breeding, a plateau is reached where artificial selection is no longer effective. This is called the ___. a) realized heritability b) selective limit c) realized limit d) selection coefficient
b) selective limit
(ch26) which of the following types of selection favors the survival of individuals with the intermediate phenotype? a) disruptive selection b) stabilization selection c) directional selection d) none of the answers are correct
b) stabilization selection
(ch15) A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to histones. What effect would you expect this mutation has on the expression of this gene? a) the expression of the gene would be abnormally high b) the expression of the gene would abnormally low or absent c) the promoter of the gene will be constantly available to transcription factors and RNA polymerase d) the gene would encode a different protein instead e) the effect on gene expression is impossible predict
b) the expression of the gene would abnormally low or absent
