Exam 3, genetics
Epigenetic modifications to the genome alter the spacing of nucleosomes. Sort the typical characteristics of each configuration to their respective bins. A) genes cannot be transcribed B) genes are likely transcribed C) DNA is unmethylated D) DNA is methylated at CpG islands E) histones are acetylated F) histones are deacetylated
"Open" configuration - nucleosomes spaced out B, C, E "Closed" configuration - DNA tightly wound on nucleosomes A, D, F
Closely linked genes don't follow the law of independent assortment A) true B) false
A
Different modification of the histone have different effects on gene expression. For instance, the ninth amino acid of histone 3 is a lysine (H3K9) can be acetylated once or methylated up to three times. Which of the following is true regarding H3K9 modification? A) If H3K9 has three methyl groups, then the gene will be repressed. B) If H3K9 has three methyl groups, it is maximally activated compared to only having one methyl group. C) If H3K9 has two methyl groups, then the gene will be activated. D) If H3K9 is acetylated, then the gene will be repressed. E) If H3K9 has a single methyl group, then the gene will be repressed.
A
Electron microscopy of metaphase chromosomes demonstrated various degrees of coiling. What was the name of the model that depicted this process? A) folded-fiber B) double-standed C) packing D) condensation E) chromatid folding
A
In this system, the presence of oil A) induces expression of the operon. B) represses expression of the operon.
A
Considering the electromagnetic spectrum, identify likely mutagens from the following list. Select all that apply. A) ultraviolet B) infrared C) microwaves D) X-rays E) radio waves F) cosmic rays G) gamma rays
A, D, F, G
Inducible system: The repressor is normally ___, but the inducer makes it ___. Repressible system: The repressor is ___, but the corepressor makes it ___. A) active B) inactive
A; B; B; A
A protein, like the lac repressor, is said to be ________ because when it binds lactose, it structurally changes and its chemical activity also changes. A) multimeric B) allosteric C) structural D) enzymatic E) digestive
B
Approximately 5% of the cytosine residues are methylated in the genome of any given eukaryote. In what way is DNA methylation related to genetic regulation? A) As DNA methylation increases, gene expression increases. B) As DNA methylation increases, gene expression decreases. C) There is no relationship between DNA methylatin and gene expression.
B
Considering the location of genes in the interphase nucleus, certain chromosomal territories appear to exist. Specifically, ________. A) large chromosomes are more likely to be located in the center of the nucleus B) each chromosome appears to occupy a discrete domain C) gene-poor regions of chromosomes are located outside the nucleus, whereas gene-rich regions of chromosomes are located inside the nucleus D) even-numbered chromosomes are located in the interior of the nucleus, whereas odd-numbered chromosomes are located peripherally
B
Which of the following would be an example of a cis acting eukaryotic gene regulatory element? A) TATA binding protein B) enhancer C) general transcription factors D) RNA polymerase E) metallothionein
B
Enhancers are said to be cis-acting. What is meant by cis-acting, and what are enhancers? Select all that apply. A) Cis-acting means that the genes under control must be on another chromosome, not where the cis-acting element is. B) Enhancers are sections of DNA that activate transcription of other sections of DNA on the chromosome. C) Cis-acting means that the genes under control must be on the same chromosome as the cis-acting element. D) Cis-acting means that the genes under control must be located in the same locus, where the cis-acting element is. E) Enhancers are sections of DNA that activate methylation of other sections of DNA on the chromosome. F) Enhancers are sections of DNA that inhibit binding of transcription factors to DNA.
B; C
Enzymes that are continuously produced are said to have a(n) ________ expression. A) negative B) positive C) constitutive D) inducible E) repressible
C
Germ cell mutations ________. A) are only seen in females B) are the cause of testicular cancer C) are usually found in every cell of the next generation D) affect somatic cell function in the current generation E) are of no consequence to the next generation
C
In a particular species, a typical somatic cell has 26 chromosomes, how many chromosomes are expected after the S phase? A) 7 B) 13 C) 26 D) 52 E) 128
C
What evidence suggests otherwise? A) Most known sources of radiation are human-made, but natural sources are more harmful. Human-made radiation exposure is not a major factor. B) Approximately half of the radiation exposure to humans comes from natural sources and half comes from human-made sources. Although diagnostic X rays do contribute about 10 percent of the exposure, other forms of human-made forms of radiation contribute only a relatively small amount. Human-made radiation exposure is not a major factor. C) Approximately 78 percent of the radiation exposure to humans comes from natural sources. Although diagnostic X rays do contribute about 10 percent of the exposure, other forms of human-made forms of radiation contribute only a relatively small amount. Human-made radiation exposure is not a major factor.
C
A mutation that changes an amino acid-coding codon to a stop codon is classified as what kind of mutation? A) conditional B) neutral C) missense D) nonsense E) silent
D
Until the mid-1940s, most scientists considered protein to be the likely candidates for the genetic material, because proteins are: A) simple, rare molecules that are important in nutritional content B) present in the atmosphere and widely known as polypeptides C) very rare, narrowly distributed in cells, and have uniform structural and functional diversity D) abundant, widely distributed in cells, have great structural and functional diversity E) non of the above
D
During interphase of the cell cycle, ___ A) DNA recombines B) sister chromatids move to opposite poles C) the nuclear membrane dissappears D) RNA replicates E) DNA content essentially doubles
E
Mutations that arise in nature, from no particular artificial agent, are called ________. A) nutritional mutations B) cosmic mutations C) induced mutations D) chromosomal losses E) spontaneous mutations
E
The nuclear regions that contain RNA polymerase and transcription regulatory molecules that help compartmentalize eukaryotic regulation are called ________. A) interchromatin compartments B) chromosome territories C) nucleosomes D) histones E) transcription factories
E
Transcription and translation are NOT coupled in eukaryotic cells, although both processes take place in the cytoplasm. T or F
false
Both forms of control result from an interaction of a molecule (usually considered to be a(n) ___) with the genetic material (___). Positive control occurs when the interaction ___ transcription, whereas negative control occurs when the interaction ___ transcription. stimulates; inhibits; nucleotide; protein; either RNA or DNA; DNA; RNA; amino acid
protein; either RNA or DNA; stimulates; inhibits
If the new mutation were dominant and passed to the next generation, it ___ expressed. New recessive mutations ___ normally expressed in the next generation unless, through a combination with a like mutation from the other parent, they are ___. heterozygous, homozygous, would be, would not be, are, are not
would be; are not; homozygous
Is there a risk for epigenetic linked diseases in using artificial reproductive technologies (ART) such as in vitro fertilization? A) Yes. There is an increase in imprinting errors, and maternal specific methylation is reduced when using ART. B) Yes. The mutational rate in sex chromosomes is increased when using ART, especially in the Y-chromosome. C) No. There is no change in epigenetic patterns when using ART. D) No. There is an increase in imprinting errors when using ART but it does not affect the health status of the fetus.
A
The cAMP-CAP complex and RNA polymerase bind more efficiently to the lac operon together than either does alone. What term is applied to this increased efficiency of binding? A) cooperative binding B) activation binding C) regulative binding D) dissociative binding
A
Three human disorders−−fragile X syndrome, myotonic dystrophy, and Huntington's disease−−are conceptually linked by a common mode of molecular upset. Choose the phenomenon that links these disorders. A) All three are caused by disparate genes, but each gene was found to contain repeats of a unique trinucleotide sequence. B) All three are caused by disparate genes, but each gene was found to contain repeats of the same trinucleotide sequence. C) All three are X-linked, but each gene was found to contain repeats of the same trinucleotide sequence. D) All three are X-linked, but each gene was found to contain repeats of a unique trinucleotide sequence.
A
To translate the three enzymes of the lac operon, ________ mRNA molecule(s) is/are transcribed. A) 1 B) 0 C) 4 D) 2 E) 3
A
What are DNMT1, DNMT3a, and DNMT3b? A) DNA methyltransferases B) lysine demethylases C) hitsone acetyltransferases D) protein methyltransferases
A
What is meant by the term chiasma? A) area where chromatids intertwine during meiosis B) a deep chasm in the mountains C) diploid tendency D) phases of mitosis E) aneuploidy
A
Which category includes lysine? A) Lysine is a positively charged amino acid. B) Lysine is a negatively charged amino acid. C) Lysine is an electrically neutral amino acid.
A
Who was the Austrian monk who conducted genetic experiments on plants using quantitative methods to show that certain traits are passed from parents to offspring in predictable ways? A) Gregory Mandel B) Alfred Wallace C) Rosalin Franklin D) Charles Darwin E) Francis Paulaner
A
Why genes related to common functions are found together in operons? A) Having genes with related functions together in operons provides for coordinated responses. B) Having genes with related functions together in operons provides for the correct function of the operon even if some genes are mutated. C) Having genes with related functions together in operons decreases the possibility of mutation for every single gene in an operon. D) Having genes with related functions together in operons provides inhibition of the response if a mutation occurs.
A
What advantages do regulatory systems provide to these organisms? Select all that apply. A) Regulatory systems provide an efficient response to available environmental resources. B) Regulatory systems provide an efficient response to protect bacteria from harmful environmental factors. C) Regulatory systems enable bacteria to turn off metabolic functions when they are not needed. D) Regulatory systems enable faster rates of transcription when bacteria enter a new environment. E) Regulatory systems enable bacteria to function normally in the absence of nutrient medium.
A; B; C
Choose three characteristics of enhancers and silencers. Select the three correct statements. A) Their orientation may be inverted without significant effect. B) They can act only at a little distance from the promoter. C) They can act at a great distance from the promoter. D) They can regulate other genes when inserted. E) They can only act if they are placed downstream from the promoter. F) They can regulate only one gene or group of closely related genes. G) An enhancer can regulate many different genes, while a silencer regulates only one gene or group of closely related genes.
A; C; D
Transcription factors are important molecules that regulate gene activity in eukaryotes. What are the two general classes of transcription factors that exist in eukaryotes? Select the two classes. A) activators and repressors B) activator C) senhancers and silencers D) general transcription factors E) promoters
A; D
Which two mutations would result in a uvrA constitutive phenotype? Indicate the actual genotypes involved. Select the two correct answers. A) mutation OuvrA-OuvrA- (mutation in the operator) B) mutation purvA-purvA- (mutation in the promotor) C) mutation uvrA-uvrA- (mutation in the gene itself) D) mutation lexA-lexA- (mutation in the repressor gene product)
A; D
All forms of autosomal trisomy are prenatally fatal A) Ture B) False
B
Early in the 20th century, Sutton and Boveri documented that the movement of chromosomes during meiosis is identical to the behavior of genes during gamete formation. They proposed that genes are carried on chromosomes, which led to the basis of the ___. A) folded fiber B) chromosome theory of inheritance C) DNA theory of inheritance D) 3 laws of Darwin E) all of the above
B
If a promoter region is mutated in such a way that it can no longer be methylated, what would the most likely effect be? A) The gene linked to the promoter would be expressed at regular levels. B) The gene linked to that promoter would be over expressed. C) The gene linked to the promoter would be under expressed. D) The gene linked to the promoter would still be expressed, but the protein should contain different amino acids. E) The gene linked to that promoter would not undergo replication.
B
In negative control of gene expression, A) binding of the regulatory molecule to DNA stimulates transcription. B) removal of the regulatory molecule from DNA stimulates transcription.
B
In positive control of gene expression, A) the regulatory molecule interferes with transcription. B) the regulatory molecule stimulates transcription.
B
In some rare cases, there is an inheritance pattern where neither alleles is dominant and the result is a blending of the two parental phenotypes: A) Mendel's 3rd law B) partial or incomplete dominance C) codominance D) dominance E) recessive
B
Is the constitutive mutation in the trans-acting reg element or in the A) cis-acting o operator element? B) trans-acting reg elementcis-acting o operator element
B
The regulatory molecule is A) a repressor; it inihibits transcription. B) an activator; it simulates transcription.
B
Two modular elements that appear as consensus sequences upstream from RNA polymerase II transcription start sites are ________. A) TTAA and CCTT B) TATA and CAAT C) enhancers and telomeres D) rDNA and nucleolar organizers E) microsatellites and transposons
B
We discussed a type of mutation in an essential gene, that results in an allele that can be tolerated only if heterozygous, homozygous don't survive. A) ribosomal mutation B) recessive lethal C) dominant lethal D) Huntington's disease E) Bombay syndrome
B
What are the terms used to describe chromosome morphologies, whit respect to centromere position A) interphase; prophase; metaphase; anaphase; telophase B) metacentric, submetacentric, acrocentric, telocentric C) endoplasmic reticulum, RNA, DNA, uracil D) amino acids E) telomeres
B
What is an allosteric molecule? A) Binding of these molecules alters the secondary structure of the mRNA, leading to premature transcription termination or repression of translation. B) One that can change in shape and chemical activity while interacting with other molecules. C) These molecules can change conformation and function while being exposed to high temperatures. D) Due to these molecules, bacteria can sense the population size and act in ways that enhance survival and functioning of the group.
B
What term would be applied to a regulatory condition that occurs when a protein is associated with a particular section of DNA and greatly reduces transcription? A) stimulation B) negative control C) activation D) induction E) positive control
B
Which of the following is the most common place to find DNA methylation? A) on cytosines when they are base paired to guanines B) on cytosines when adjacent to guanines C) on guanines when adjacent to other guanines D) on guanines when adjacent to cytosines E) on cytosines when adjacent to other cytosines
B
Which of the following mutations would NOT be classified as a transversion? A) CGA to CGT B) CGA to a TGA C) CGA to a CGU D) CGA to a GGA E) CGA to a CCA
B
Style of maternal care is transmitted across rat generations through epigenetic events that take place early in postnatal life. In rats and humans, the brain mediates stress reactions by controlling levels of glucocorticoid hormones via action of glucocorticoid receptors (GRs). High levels of GR expression can increase adaptation to stress; reduced levels can lead to poor stress adaptation. Newborn rats exposed to HIGH maternal nurturing had a ___ phenotype. This was shown to correlate with increased release of serotonin and increased GR expression due to ___ histone acetylation and ___ DNA methylation levels in the GR gene promoter. Newborn rats exposed to LOW maternal nurturing had a ___ phenotype. This was shown to correlate with decreased release of serotonin and decreased GR expression due to ___ histone acetylation and ___ DNA methylation levels in the GR gene promoter. A) increased B) less stressed C) decrease D) more stressed
B; A; C; D; C; A
The binding of transcription factors requires accessing ___ DNA. When nucleosomes are tightly associated with the DNA, transcription proteins ___ access the DNA; however, when nucleosomes are loosely associated with the DNA, then the DNA transcription proteins have ___ to the DNA. A) internucleosomal B) nucleosomal C) can D) cannot E) an easier access F) no access
B; C; E
Choose the three major epigenetic mechanisms. Select the three сorrect answers. A) addition or removal of phosphate groups to and from DNA B) regulation of gene expression by noncoding RNA molecules C) adding and removing chemical groups to and from histone proteins D) removing introns from pre-mRNA molecules E) regulation of gene expression by micro RNA molecules F) addition or removal of methyl groups to and from DNA G) adding and removing lncRNAs to and from histone proteins
B; C; F
A fundamental property of DNA's bases that is necessary for the double-standed nature of its structure is ___ A) high pH B) optical properties C) complememtarity D) 5 possible nucleotides E) non of the above
C
In bacteria and eukaryotes, a mutation is when ________. A) the amino acid sequence in a protein molecule is directly. B) changedDNA is unable to be replicated C) the nucleotide sequence in a DNA molecule is directly changed D) the nucleotide sequence in an mRNA molecule is directly changed E) the expression of a gene changes without the DNA sequence being changed
C
In humans, the number of genes that are imprinted is less than 1%. These imprinted genes are usually associated with ________. A) metabolic pathways B) apoptosis C) growth regulation D) DNA replication E) brain function
C
In most species, chromosomes occur in pairs. In such organisms, the characteristic number of chromosomes is called the ___ number. It is usually symbolized as ___. A) haploid; n B) haploid; 2n C) diploid; 2n D) diploid; n E) None of the answers listed are correct
C
In terms of overall methylation, what is the most accurate way to describe the genomes of cancer cells? A) A few types of cancers are have hypomethylated genomes, but it is not common in most types of cancers. B) A few types of cancers are have hypermethylated genomes, but it is not common in most types of cancers. C) Cancer cells have an overall hypomethylated genome compared to healthy cells. D) Cancer cells have equivalent methylated genomes compared to healthy cells. E) Cancer cells have an overall hypermethylated genome compared to healthy cells.
C
Present an overview of bacterial gene regulation in terms of growth efficiency. A) Genetic systems have evolved that allow for "in-house" production of growth substances when not supplied. When needed substances are in full supply, such genetic systems are repressed. B) Genetic systems have evolved that allow for "in-house" production of growth substances when in full supply. When needed substances are not supplied, such genetic systems are repressed. C) Genetic systems have evolved that allow for "in-house" production of growth substances when not supplied or when in full supply. When needed substances are in full supply, such genetic systems are repressed. D) Genetic systems have evolved that allow for "in-house" production of growth substances when not supplied or when in full supply. When needed substances are not supplied, such genetic systems are repressed.
C
Tautomeric shifts ________. A) allow pyrimidines to bind to pyrimidines B) allow purines to bind to purines C) can cause missense mutations due to mispairings D) are known to cause insertion or deletion mutations E) are likely to cause frameshifts
C
The type of cross carried out to help show that both male and female parents contribute equally to the autosomal characteristics inherited by offspring is called a ___ cross. A) monohybrid B) dihybrid C) reciprocal D) Punnet square E) true breeding
C
What do they do? A) DNMT1 adds methyl groups to cytosines that are typically adjacent to guanines and DNMT3a and DNMT3b add methyl groups to adenines adjacent to thymines. B) They all add methyl groups to adenines that are typically adjacent to guanines. C) They all add methyl groups to cytosines that are typically adjacent to guanines. D) DNMT1 adds methyl groups to guanines that are typically adjacent to cytosines and DNMT3a and DNMT3b add methyl groups to cytosines adjacent to adenines.
C
What is the role of the lacZ gene product, the enzyme ß-galactosidase? A) It removes the toxic by-products of lactose digestion from the bacterial cell. B) It facilitates the entry of lactose into the bacterial cell. C) It converts lactose to glucose and galactose. D) It converts simple sugars to lactose.
C
What term refers to clusters of bacterial genes that are under the control of a single regulatory region? A) attenuation B) prototroph C) operon D) allosteric E) autotroph
C
Which of the following clusters of terms applies when addressing enhancers or silencers as elements associated with eukaryotic genetic regulation? A) cis-acting, fixed position, fixed orientation B) trans- and cis-acting, variable position C) cis-acting, variable orientation, variable position D) cis-acting, variable position, fixed orientation E) trans-acting, fixed position, fixed orientation
C
Which process seems to be the most similar between eukaryotic and prokaryotic genetic regulation? A) 5′-capping regulation B) poly(A) tail addition C) transcriptional regulation D) intron/exon shuffling E) RNA splicing regulation
C
Why must a transcription factor have at least two functional domains? A) One domain binds to DNA in insulators, and the other binds to RNA transcript and RNA polymerase to repress transcription. B) One domain binds to RNA polymerase, and the other binds to other transcription factors to initiate transcription. C) One domain binds to DNA in promoters and enhancers, and the other binds to other transcription factors or RNA polymerase to activate transcription. D) One domain binds to DNA in enhancers, and the other binds to DNA in promoters to enable transcription.
C
X chromosome inactivation is the result of which of the following ?- A) Expression of a miRNA B) Expression of a sex-linked gene encoding a DNA methylase C) Random monoallelic expression D) Expression of a sex-linked gene encoding a histone deacetylase
C
________ is the study of phenomena and mechanisms that cause chromosome-associated heritable changes to gene expression that are not dependent on changes in DNA sequence. A) Preformation B) Transmission genetics C) Epigenetics D) Population genetics E) Mutagenesis
C
at 6-8 weeks of development the ___ gene becomes active in XY embryos. A) tRNA B) MSY C) SRY D) PAR E) mitochondrial
C
lacI codes for a(n) ________, and when lacI is mutated, the lac operon is ________. A) structural gene; never expressed B) activator; never expressed C) repressor; constitutively expressed D) activator; constitutively expressed E) repressor; never expressed
C
One can make partial diploid strains using ___ strain. OuvrA- will (given the other genes brought in by the plasmid) be dominant to ___ and lexA- will be recessive to ___ . OuvrA- will act in a ___ manner. A) OuvrA- B) OuvrA+ C) F' D) p- E) OuvrAC F) trans G) lexA- H) lexA+ I) lexAC J) cis
C; B; H; j
Environmental agents such as nutrition and chemical exposure can alter gene expression by affecting the epigenome. Epigenetic changes may also have important effects on behavior phenotypes. Which of these examples correctly describe explicit evidence supporting epigenetic traits as heritable? Select the two correct answers. A) Exposure of pregnant women to poor nutrition during famines affects their developing fetuses and has detrimental effects during adulthood and subsequent generations. B) The level of maternal nurturing that children receive results in distinctive epigenetic changes to the human nervous system that can be transmitted across generations. C) Feeding pregnant mice methylation precursors shifts the coat color of their offspring from yellow (unmethylated promoter) to pseudoagouti (highly methylated promoter). D) The level of maternal nurturing in newborn rats causes differential gene expression that corresponds with stressed phenotypes that can be transmitted across generations.
C; D
How do they affect gene transcription? Select all that apply. A) DNMT3a is responsible for maintaining epigenetic patterns. B) DNMT1 is primarily responsible for establishing the original epigenetic patterns. C) DNMT1 is primarily responsible for maintaining epigenetic patterns. D) DNMT3a and DNMT3b are responsible for establishing the original epigenetic patterns. E) DNMT3b is responsible for maintaining epigenetic patterns.
C; D
A recessive allele in tigers cause white fur. If 2 normally pigmented tigers are mated and produce one white kitten, what precentage of their offspring would be expected to have normal pigments? A) 25% B) 50% C) 66% D) 75% E) 100%
D
All of the following are epigenetic mechanisms, EXCEPT ________. A) changing gene expression by the use of small noncoding RNAs B) changing gene expression by adding and removing chemical groups to histone proteins C) changing gene expression by adding and removing methyl groups to DNA D) changing gene expression by changing the nucleotide sequence through mutation E) changing gene expression by the use of long noncoding RNAs
D
Homologous chromosomes are those that van be matched by virtue of their similar structure and function within the nucleus. How many pairs of autosomes does each normal human cell have? A) 46 B) 23 C) 44 D) 22 E) 45, X
D
How does DNA methylation regulate gene activity? A) by changing DNA-DNA hydrogen bonding B) by inhibiting RNA polymeraseincreasing the level of transcription C) by promoting the binding of transcription factors to DNA D) by adding methyl groups to the cytosine of CG doublets in DNA
D
How does this property of lysine allow it to interact with DNADNA? A) Positively charged lysine side chains can form ionic bonds with negatively charged nitrogenous bases in the DNA. B) Lysine can form covalent bonds with nitrogenous bases in the DNA. C) Lysine can form covalent bonds with phosphate groups in the DNA backbone. D) Positively charged lysine side chains can form ionic bonds with negatively charged phosphate groups in the DNADNA backbone.
D
In humans, we have chromosomal determination of sex and the homogametic sex is: A) the endosymbiont hypothesis B) the homologous hypothesis C) analogous hypothesis D) the female E) the male
D
TSD: Temperature-dependent sex determination is a form of environmental versus chromosomal sex determination that occurs mainly in: A) bacteria B) Chlamydomonas C) fish D) reptiles E) snails
D
What is the function of the lacY gene in the lac operon? A) The lacY gene codes for ββ-galactosidase, a protein that cleaves the lactose sugar into its components, glucose and galactose. B) The lacY gene codes for transacetylase. Its physiological role is still not completely clear but it may be involved in the removal of toxic by-products of lactose digestion from the cell. C) The lacY gene codes for adenyl cyclase, a protein that catalyzes the conversion of ATP to cAMP. D) The lacY gene codes for permease, a membrane-bound protein that transports lactose into the bacterial cell.
D
Which binds to the operator of the lac operon? A) permease B) activator C) beta galactosidase D) repressor E) lactose
D
Which of the following elements function specifically in eukaryotic transcription and gene expression? A) Pribnow boxes and enhancers B) Shine-Dalgarno sequences and sigma factors C) origin DNA and promoters D) promoters and enhancers
D
Which of the following is true about histone acetyltransferase (HAT)? A) HATs will make the chromatin more compacted and less available to transcription regulatory proteins. B) HATs have an overall effect of increasing the positive charges on DNA. C) HATs will add acetyl groups to DNA. D) HATs are usually linked to increasing gene expression. E) HATs will remove acetyl groups from histone proteins.
D
Which of the following statements best describes the trp operon? A) It is inducible and under positive control. B) It is inducible and under negative control. C) It is repressible and under positive control. D) It is repressible and under negative control.
D
the physical characteristics of a plant or animal that result from their genetic makeup are collectively known as an organism's ___ A) sexual reproduction B) meiotic driver C) mitotic drive D) phenotype E) genotype
D
HATs usually lead to gene ___, and HDACs usually lead to gene ___. In cancer cells if HATs are mutated, then genes that are normally ___ to prevent cancer are now ___, which can lead to cancer. In addition, in cancer cells if HDACs are mutated, then genes that are normally ___ to suppress cancer will now be ___ leading to cancer. A) active B) repressed C) repression D) expression E) inactive F) expressed
D; C; A; B; E; F
Choose three levels or types of genetic regulation in eukaryotes. Select the three сorrect answers. A) DNA degradation B) ubiquitin tagging C) replication regulation D) posttranslational regulation E) posttranscriptional regulation F) transcriptional regulation G) reparation regulation H) ribosome assembly regulation
D; E; F
DNA methyltransferases (DNMTs) play a major role in gene regulation. Sort the items to their respective bins. A) create original DNA methylation patterns B) add a methyl group resulting in 5-methylcytosine C) maintain established DNA methylation patterns D) act on cytosine bases located adjacent to a guanine base E) act on CpG dinucleotides located in repetitive DNA sequences of heterochromatin
DNMT1: C DNMT3a and DNMT3b: A All DNMTs: B, D, E
A regulatory sequence of DNA that is 10,000 base pairs away from the gene it regulates is mutated. The result is that the gene being regulated is now expressed at a higher rate compared to when this regulatory sequence was not mutated. What would this sequence of DNA best be called? A) zinc finger motif B) insulator C) activator protein D) enhancer E) silencer
E
Alternative forms of a gene are called ___ A) chromosomes B) recessives C) traits D) phenotypes E) alleles
E
DNA is methylated on which nucleotides? A) uracil B) guanine C) thymine D) adenine E) cytosine
E
Which of the following is an example of genomic imprinting in humans? A) Human males have only one Y-chromosome and one X-chromosome. B) The maternal and paternal alleles of a gene pair are both expressed. C) A random pattern of autosomal allele inactivation is observed. D) One of the two X-chromosomes in females is randomly expressed and the other is repressed. E) In some allele pairs, only the paternal sourced allele is expressed, and in others, only the maternal sourced allele is expressed.
E
Regarding regulation of the lac operon, in the absence of glucose, CAP (dependent on ___) binds to the CAP site and facilitates transcription (positive control). Transcription of the operon is inhibited in the presence of glucose (catabolite repression). A) Inhibits B) stimulated C) cAMP and adenyl cyclase D) CO2 and a-ketoglutarate dehydrogenase E) absence F) presence G) faciliates H) inhibited I) NADPH2 and NADPH dehydrogenase
E; C; G; H; F
Histones can be covalently modified. Place the terms in the appropriate blanks to complete the sentences. Terms can be used once, more than once, or not at all. The amino acids near the ___ ends of histones are typically modified. The principal chemical modifications to histones are the addition of ___, ___, or ___ groups. Histone modifications occur at specific amino acids of histones H2A, H2B, H3, and ___. The shorthand nomenclature of H3K9ac describes that the ___ at position 9 of histone 3 has a(n) ___ group. A) methyl B) lysine C) sulfhydryl D) H4 E) N-terminal F) H1 G) C-terminal H) phosphate I) acetyl
E; I; A; H; D; B; I
Acetylation of the lysine side chain removes its ___, preventing the ionic interaction with phosphate and ___ the interaction between the histone and the DNA. As a result, genes are more accessible ___. A) but stay repressed B) negative charge C) increasing D) and able to be expressed E) decreasing F) positive charge
F; E; D
Where do they bind and what are their effects? Drag the appropriate items to their respective bins. A) important in basal levels of transcription B) bind at more distant regions, such as enhancers and silencer sequences C) are important in tissue specific and developmental regulation D) assemble at promoter regions adjacent to the site of transcription E) are responsible for altered transcription
General transcription factors A; D Activators and repressors B; C; E
