Mastering Biology Chapter 22, BIO EXAM 3
Homology
"the study of likeness" , provides further evidence for the relatedness of organism
Functional genomics face two major challenges:
- the large number of genes in eukaryotic genomes - the distinctive pattern of gene expression in different tissues at different times
The CAP-cAMP complex binds the DNA at a ...
... CAP binding site just upstream of the promoter
If cAMP levels are low...
... CAP is not active and transcription is not increased
The amount of cAMP and the rate of lac transcription are...
... inversely related to the concentrarion of glucose
Binding of this site aids RNA polymerase to bind the...
... promoter and increases transcription rate
When glucose is high (and cAMP levels are low), even when lactose is available...
.... the lac operon fails to transcribe frequently
When glucose is low and cAMP is high...
...cAMP binds to a protein called the catabolite activator protein (CAP)
Predict whether a bacterial colony with a mutation in a required gene for lactose metabolism will grow on: a) An agar plate containing only glucose. A) Yes B) No b) An agar plate containing only lactose. A) Yes B) No
1. Yes 2. NO
Which term describes a trait that increases an individual's ability to survive in a particular environment?
Adaptation An adaptation is a trait that increases an individual's ability to survive in a particular environment.
Overview of gene regulation: Eukaryotic gene expression can be regulated at 3 steps within the nucleus
1. chromatin remodeling: DNA packaged with proteins into complex structures that must be opened for transcription to occur 2. transcriptional regulation: transcription can be initiated only when specific proteins bind to the promoter and to specific regulatory sequences 3. alternative splicing: allows a single gene to code for several different products
Isolating mutants with respect to a particular trait is a 2 step process
1. generate a large number of individuals with mutations at random locations in their genomes 2. use genetic screening on the mutants to find individuals with defects in the process or pathway in question. In this approach, we will use replica plating.
Darwin's Process of Evolution by Natural Selection
1. individuals that make up a population vary in their traits 2. some of these trait differences are heritable, meaning they are passed on to offspring 3. In each generation, many more offspring are produced that can survive. Only some individuals in the population survive long enough to produce offspring. Of these, some will produce more offspring than others. 4. individuals with certain heritable traits are more likely to survive and reproduce. natural selection occurs when individuals with certain traits produce more offspring than do individuals with certain traits produce more offspring than do individuals without those traits. these selected traits will increase in frequency in the population from one generation to the next, causing evolution
long answer question 4. In negative control of transcription, a gene is activated when _____. A) a kinase adds a phosphate to DNA B) lactose is transported into the cell C) a regulatory protein binds to DNA D) a regulatory protein is removed from DNA 5. Why must a small amount of the lacZ and lacY genes always be expressed in E. coli, even in the presence of the repressor coded for by the lacI gene? Hint: What does the protein code for by the lacY gene do?
4. D 5. it has to be present in the cell in order for lactose to enter the cell
4. In the shotgun genome sequencing approach, 160 kb genomic DNA fragments are broken into 1 kb fragments (in "shotgun clones") that are sequenced. Why is this step required (ie—why not use the 160 kb genomic DNA fragments as templates for sequencing reactions)? 5. How are the DNA sequences of the many different 1 kb fragments in shotgun clones used to reconstruct the original 160 kb genomic DNA fragments?
4. because the sequencing can only work if the fragment is 1kb or smaller. 5. computer will look for overlapping regions
Once an mRNA is in the cytoplasm, gene expression is controlled by molecules that regulate the following;
4: the life span of mRNAs 5. The efficiency of translation-to translate or not to translate 6: the activation or inactivation of protein products
Where are the Galapagos Islands located?
600 miles west of Ecuador, near the equator
Which of the following would you expect to find in an inducible system? A. A repressor protein, which is bound to DNA in absence of any other factor. B. A repressor protein, which is bound to DNA in the presence of a corepressor. C.An activator protein, which is bound to DNA in absence of any other factor. D.An activator protein, which is bound to DNA only in the absence of an inhibitor.
A. A repressor protein, which is bound to DNA in absence of any other factor.
Which of the following statements best describes the outcome from culturing E. coli mutant for lacI- (encoding a lac repressor protein) on agar indicator plates coated with X-Gal and containing only lactose? A. Blue bacterial colonies will grow. B. White bacterial colonies will grow. C. No bacterial colonies will grow. D. Some bacterial colonies that grow will be blue and others will be white.
A. Blue bacterial colonies will grow
What is the correct sequence of events in generating the Southern blot above? A. First separate DNA fragments on an agarose gel, then transfer DNA to filter paper, expose paper to radioactive DNA probe, and finally detect DNA probe with X-ray film. B. First expose DNA fragments to radioactive probe, then separate DNA fragments on an agarose gel, transfer DNA to filter paper, and finally detect DNA probe with X-ray film. C. First transfer DNA to filter paper, followed by separation of DNA fragments on an agarose gel, expose paper to radioactive DNA probe, and finally detect DNA probe with X-ray film. D. First separate DNA fragments on an agarose gel, followed by exposure of DNA fragments to radioactive DNA probe, transfer DNA to filter paper, and finally detect DNA probe with X-ray film.
A. First separate DNA fragments on an agarose gel, then transfer DNA to filter paper, expose paper to radioactive DNA probe, and finally detect DNA probe with X-ray film.
A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true?
A. The amount of available food may have increased. and C. The number of predators that prey upon squirrels may have decreased.
To test for opening of chromatin only in areas with transcriptionally active genes, we can isolate chromatin from red blood cells and treat with DNAase... Following DNAase treatment of red blood cell chromatin, could you still detect the presence of ovalbumin, a gene not expressed in red blood cells? A) Yes B) No C) No way to predict
A. Yes
... to test Lamarck's idea of the "inheritance of acquired characteristics," the tails of mice were cut off, and the mice were allowed to mate? In this experiment, the progeny will: A. all have tails B. have much shorter tails than their parents. C. all lack tails
A. all have tails
What is the natural function of restriction enzymes? Restriction enzymes protect bacteria by: A. cleaving (cutting) the DNA of infecting viruses. B. cleaving (cutting) their own DNA. C. methylating their own DNA. D. methylating the DNA of infecting viruses.
A. cleaving (cutting) the DNA of infecting viruses.
... instead of cropping off the mouse's tail they had chosen those with the shortest tails for breeding with others with short tails for several generations? Tail length will _______ from generation to generation. A. decrease B. increase c. remain unchanged
A. decrease
You are using a DNA microarray to test the effect of a toxin on gene expression. To perform this experiment, you administer the toxin to cells grown in culture for several days. As a negative control, you culture cells without the toxin. You generate cDNA from cells under each condition and label the cDNA with fluorescent tags for use in a microarray—cDNA from cells exposed to the toxin was labeled in green and cDNA from control cells without the toxin was labeled in red. To identify genes whose expression was unchanged by the toxin after probing a DNA microarray with your labeled cDNA, you would search for spots on the microarray that: A. either fluoresced in yellow or did not fluoresce. B. either fluoresced in red or did not fluoresce. C. either fluoresced in red or yellow. D. either fluoresced in green or red. E. fluoresced in yellow.
A. either fluoresced in yellow or did not fluoresce.
Which of the following levels of gene expression regulation allows the most efficient (i.e.--most energetically favorable) response to environmental change? A. transcriptional control B. translational control C. post-translational control
A. transcriptional control
Which of the following pieces of evidence most strongly supports the common origin of all life on Earth?
All organisms use essentially the same genetic code.
What would happen in an in vitro dideoxy DNA sequencing mixture containing the four ddNTPs and no dNTPs?
All the products would be one nucleotide longer than the primer
Which of these conditions should completely prevent the occurrence of evolution in a population over time?
All variation between individuals is due only to environmental factors.
You are doing a genetics experiment with the fruit fly, Drosophila melanogaster. In the "P" generation, you cross two true-breeding flies. The female parent is homozygous for dominant body color alleles and is homozygous for recessive wing development alleles (♀= BBnn - brown body color and wingless). The male parent is homozygous for recessive body color alleles and is homozygous for dominant wing development alleles (♂ = bbNN - black body color and normal wings). You now take an F1 female and cross her to a true-breeding black body color, wingless male. You count 1600 offspring in the F2 generation. If the body color and wing development genes are linked and no recombination occurred, you would expect to count: Answer choice F2 offspring (#, phenotype, genotype) A 400 brown, winged flies (BbNn) 400 black, winged flies (bbNn) 400 brown, wingless flies (Bbnn) 400 black, wingless flies (bbnn) B 0 brown, winged flies (BbNn) 800 black, winged flies (bbNn) 800 brown, wingless flies (Bbnn) 0 black, wingless flies (bbnn) C 200 brown, winged flies (BbNn) 600 black, winged flies (bbNn) 600 brown, wingless flies (Bbnn) 200 black, wingless flies (bbnn) D 600 brown, winged flies (BbNn) 200 black, winged flies (bbNn) 200 brown, wingless flies (Bbnn) 600 black, wingless flies (bbnn) E 800 brown, winged flies (BbNn) 0 black, winged flies (bbNn) 0 brown, wingless flies (Bbnn) 800 black, wingless flies (bbnn)
B 0 brown, winged flies (BbNn) 800 black, winged flies (bbNn) 800 brown, wingless flies (Bbnn) 0 black, wingless flies (bbnn)
Is the following statement True or False? "In his book The Origin of Species, Darwin clearly stated how variations came about and how they were transmitted." A. True B. False
B. False
To test for opening of chromatin only in areas with transcriptionally active genes, we can isolate chromatin from red blood cells and treat with DNAase... Following DNAase treatment of red blood cell chromatin, could you still detect the presence of b-globin, a red blood cell-specific gene? A. Yes B. No C. No way to predict
B. NO. Globin genes are found in oxygen transport so it is expressed in red blood cells. Beta-globin is expressed in cell type so would be broken up.
Which of the following statements about the lac operon is FALSE? A. When lactose binds to the lac repressor protein, the lac repressor protein can no longer bind to the operator. B. When lactose binds to the operator, transcription is stimulated. C. When the lac repressor protein binds to the operator, transcription is inhibited. D. When lactose binds to the lac repressor protein, the shape of the lac repressor protein is changed. E. The lac repressor protein has binding sites for both DNA and lactose.
B. When lactose binds to the operator transcription is stimulated.
Which of the following statements best describes the outcome from culturing E. coli mutant for lacZ- (encoding β-galactosidase) on agar indicator plates coated with X-Gal and containing only glucose? A. Blue bacterial colonies will grow. B. White bacterial colonies will grow. C. No bacterial colonies will grow. D. Some bacterial colonies that grow will be blue and others will be white.
B. White bacterial colonies will grow
Which of the following statements best describes the outcome from culturing E. coli mutant for lacI- (encoding a lac repressor protein) on agar indicator plates coated with X-Gal and containing only glucose? A. Blue bacterial colonies will grow. B. White bacterial colonies will grow. C. No bacterial colonies will grow. D. Some bacterial colonies that grow will be blue and others will be white.
B. White bacterial colonies will grow.
Indicator plates coated with X-Gal can be used to detect
Beta- Galactosidase activity. Blue colonies express Beta-Galactosidase and White colones do NOT express Beta-Galactosidase
A scientist wants to insert a human gene into a bacterial plasmid. Both the human and plasmid DNA have available recognition sequences for the restriction endonucleases HindIII, EcoRI, and BamHI pictured below. What enzymes should be used for digestion (cutting) the DNA in order to insert the human gene into the plasmid? The enzyme ______ should be used to cut the human gene and the enzyme ______ should be used to cut the plasmid. A. HindIII; BamHI B. EcoRI; BamHI C. BamHI; BamHI D. BamHI; EcoRI E. BamHI; HindIII
C. BamHI; BamHI
Which of the following statements best describes the outcome from culturing E. coli mutant for lacZ- (encoding β-galactosidase) on agar indicator plates coated with X-Gal and containing only lactose? A. Blue bacterial colonies will grow. B. White bacterial colonies will grow. C. No bacterial colonies will grow. D. Some bacterial colonies that grow will be blue and others will be white.
C. No bacterial colonies will grow
A series of Hfr strains that have genotype m+ n+ o+ p+ q+ r+ are mixed with an F- strain that has genotype m- n- o- p- q- r-. Conjugation is interrupted at regular intervals and the order of the appearance of genes from the Hfr strain is determined in the recipient cells and indicated in the table below: HFR strain Order of transfer (earliest) (latest) Hfr5 m+ q+ p+ n+ r+ o+ Hfr4 n+ r+ o+ m+ q+ p+ Hfr1 o+ m+ q+ p+ n+ r+ Hfr9 q+ m+ o+ r+ n+ p+ Which of the following statements regarding the experiment above is FALSE? A. The transfer of DNA that takes place during conjugation between the Hfr and F- cells allows bacterial genes to be mapped. B. The time required for individual genes to be transferred indicates their relative positions on the bacterial chromosome. C. The orientation of the F factor is identical in each of the different Hfr strains. D. In each of the Hfr strains, the F factor has been inserted into a different location in the bacterial chromosome. E. Minutes in bacterial chromosome mapping are the equivalent to map units in eukaryotes.
C. The orientation of the F factor is identical in each of the different Hfr strains.
Which of the following statements regarding X inactivation in mammals is FALSE? A. The process is entirely random. B. X inactivation may occasionally occur in males. C. This process ensures a homogenous phenotype in heterozygotes. D. X inactivation occurs early in embryonic development.
C. This process ensures a homogenous phenotype in heterozygotes.
Can a tortoiseshell cat be male? A.Yes, all cats of this phenotype are male. B. No, it is not possible for male cats to have the tortoiseshell phenotype. C. Yes, in rare circumstances, tortoiseshell males cats are possible. D. Yes, both males and females are equally likely to be tortoiseshell.
C. Yes, in rare circumstances, tortoiseshell males cats are possible. The male could be XXY.
What happens when a dideoxyribonucleotide triphosphate (ddNTP) is incorporated into the 3' end of a growing DNA strand by DNA polymerase? A.ddNTPs permanently bind to the active site of DNA polymerase. B.ddNTPs cause DNA polymerase to break apart into small fragments. C.ddNTPs stop DNA polymerization because they lack a hydroxyl (-OH) group at their 3′ end. D.ddNTPs have no effect upon DNA polymerization. E.ddNTPs cause the release of primers from the template DNA.
C. ddNTPs stop DNA polymerization because they lack a hydroxyl (-OH) group at their 3′ end.
Which of the following levels of gene expression regulation allows the most rapid response to environmental change? A. transcriptional control B. translational control C. post-translational control
C. post-translational control
We want to use DNA microarray technology to determine which protein-coding genes are expressed in heart versus lung tissue. To begin the experiment, what do we need to extract from these tissues? A. Complementary DNA (cDNA) B. Ribosomal RNA (rRNA) C. microRNA (miRNA) D. Messenger RNA (mRNA) E. Double-stranded DNA (dsDNA)
D. Messenger RNA (mRNA)
Since DNA sequencing is based on termination of nucleic acid polymerization, why are normal deoxynucleotides (dNTPs) also included in the reaction? A. to enhance the chain termination ability of the deoxynucleotides B. to provide a substrate for DNA polymerase C. to produce a range of DNA synthesis products that terminate at every occurrence of a particular base D.to create DNA synthesis products long enough to allow running a gel E.normal deoxynucleotides are not required in the reaction
C. to produce a range of DNA synthesis products that terminate at every occurrence of a particular base
You just drank a large glass of milk and the level of lactose in your intestines is high, while the level of glucose is low. How will this condition influence the β-galactosidase activity of E. coli in your intestines? β-galactosidase activity will be: A. Low, because the cAMP-CAP complex will be unable to bind the CAP binding site. B. Low, because cAMP levels in the E. coli will be very high. C. High, because galactoside permease will open in response to low glucose levels, flooding the cells with lactose. D. High, because the functional CAP protein will bind to the CAP binding site and the lac repressor will not bind the operator. E. The level of β-galactosidase activity cannot be determined.
D. High, because the functional CAP protein will bind to the CAP binding site and the lac repressor will not bind the operator.
Which of the following statements regarding transduction is TRUE? In transduction: A. phage DNA integrates into the bacterial chromosome where it remains as an inactive prophage. B.DNA transfer is prevented in the Davis U-tube due to the presence of a filter that prevents physical contact between different bacterial strains. C.donor bacterial genes cannot be recombined into the recipient bacterial chromosome. D.a piece of the bacterial chromosome occasionally gets packaged into a viral particle. E.the addition of DNase to culture media prevents DNA transfer from donor to recipient bacterial cells.
D. a piece of the bacterial chromosome occasionally gets packaged into a viral particle.
A form of transcriptionally active chromatin is referred to as: A. a Barr body. B. heterochromatin. C. a chromosome. D. euchromatin. E. None of these
D. euchromatin.
When tryptophan is present in the culture medium, transcription of tryptophan-synthesizing genes in E. coli is stopped by a repressor binding to the: A. trp repressor B. trp operon C. trp promoter D. trp operator E. trp polymerase
D. trp operator
Like dNTPs, ddNTPs are picked up by ______ _________ and added to a growing ______ ________
DNA polymerase, DNA chain
The elaborate structure of chromatin allows
DNA to be packaged in the nucleus.
You have the following DNA template and want to use PCR to amplify the double-stranded region that is underlined. Which of the following primers should you use? LOOK AT LEARNING CAT. for pic. A. 5'-TACCAGGTAC-3' and 5'-AATGGGTAAA-3' B. 5'-CTTCTGACTG-3' and 5'-CGCAAGGCCA-3' C. 5'-ATGCATGCTG-3' and 5'-TTTCAGCATG-3' D. 5'-ATGGTCCATG-3' and 5'-TTACCCATTT-3' E. 5'-ATGGTCCATG-3' and 5'-TTTACCCATT-3'
E. 5'-ATGGTCCATG-3' and 5'-TTTACCCATT-3'
When a gene is duplicated, which of the following may occur? A.Production of the gene's product may increase. B. The two copies may become expressed in different tissues. C. One copy of the gene may accumulate deleterious (damaging) base substitutions and become functionless. D. The two copies may diverge and acquire different functions. E. All of the above.
E. All of the above.
The single, universal regulatory mechanism in eukaryotes for controlling gene expression includes: A. control of the genes transcribed and the rate they are transcribed. B. control of the processing of mRNA after it is transcribed from DNA. C. control of mRNA in the cytoplasm after it leaves the nucleus, including changes to mRNA before translation begins. D. control of polypeptides after they have been synthesized but before they are functional. E. All of these mechanisms are used; there is no single universal mechanism.
E. All of these mechanisms are used; there is no single universal mechanism.
Gene X is transcribed only in liver cells. In which of the following will the gene X sequence be found? A. kidney cDNA library B. kidney genomic library C. liver cDNA library D. A and B E. Both B and C
E. Both B and C kidney has the same genome as the liver
Imagine you are using a DNA microarray to test the effect of a drug treatment on gene expression. To perform this experiment, you administer the drug to cells grown in culture for several days. As a negative control, you culture cells under similar conditions without the drug. You generate cDNA from cells under each condition, however, you accidentally label both pools of cDNA, from drug-treated and non-treated cells with a green fluorescent tag. Following probing a DNA microarray with your labeled cDNA, you would: A. See every spot on the DNA microarray light up in green. B. Be able to detect differences in gene expression. C. See every spot on the DNA microarray light up in red. D. Be unable to determine what genes are being expressed. E. None of these answers are correct.
E. None of these answers are correct.
In the ______ (presence/absence) of lactose, the lac ______ binds to the lac ______ site. A. presence; operator; repressor B. presence; repressor; promoter C. absence; operator; promoter D. absence; operator; repressor E. absence; repressor; operator
E. absence; repressor; operator
To identify the required genes for lactose metabolism, Monod and Francois Jacob isolated _________ mutants that could NOT metabolize lactose
E. coli
What two different kinds of chromatin can be distinguished by staining the nucleus?
Euchromatin and Heterochromatin
Which of the following statements about natural selection is true?
Natural selection favors individuals that reproduce more than others. Individuals who are better able to survive and reproduce are more likely to be selected for than individuals who don't survive or cannot reproduce.
Imagine you are using a DNA microarray to test the effect of a drug treatment on gene expression. To perform this experiment, you administer the drug to cells grown in culture for several days. As a negative control, you culture cells under similar conditions without the drug. You generate cDNA from cells under each condition and label the cDNA with fluorescent tags for use in a microarray—cDNA from drug-treated cells was labeled in red and cDNA from negative control cells labeled in green. To search for genes whose expression was inhibited by drug treatment, after probing a DNA microarray with your labeled cDNA, you would search for spots on the microarray that fluoresced in:
Green
Which term describes the ability of a trait to be passed on to offspring?
Heritability Heritability is the ability of a trait to be passed on to offspring.
Which of the following statements is an accurate combination of postulates 1 and 2 of natural selection?
Heritable variation exists for traits among individuals in a population.
DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that:
Humans and chimpanzees share a relatively recent common ancestor.
Which of the following statements is an accurate combination of postulates 3 and 4 of natural selection?
Individuals experience differential success in their ability to survive or reproduce. Variation in fitness is required for selection to change the characteristics of a population over time. Remember that selection also requires that the variation in fitness be related to a heritable trait.
X-GAL
Is a dye used to detect Beta-Galactosidase activity
The theory of evolution through natural selection is considered a scientific theory because _____.
It is broad enough in scope to explain many observations. It is supported by a massive body of evidence from many disciplines. It is general enough to provide many testable hypotheses
What must be true of any organ that is described as vestigial?
It must be homologous to some feature in an ancestor.
Which pair of chickens should a farmer breed to produce larger chickens?
Large hen, large rooster
The relationship of cyclic AMP (cAMP) and glucose
Low glucose levels cause elevated levels of cyclic AMP (cAMP). The enzyme adenylyl cyclase produces cAMP from ATP and is inhibited by glucose
Two types of STRs
Microsatellites Minisatellities
The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?
Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.
Does the ability of a Mycobacterium tuberculosis cell to infect a new host depend on its drug-resistant phenotype?
No, drug-susceptible cells and drug-resistant cells are equally likely to infect a new host. A cell's drug susceptibility or resistance does not affect its ability to infect another host, although a cell's drug resistance would increase that cell's chances to spread in an environment containing antibiotics due to increased survival.
Which of the following statements about evolution by natural selection is correct?
Populations, not individuals, change when natural selection occurs.
DNA microarrays are used to
RNA expression patterns
Imagine you are using a DNA microarray to test the effect of a drug treatment on gene expression. To perform this experiment, you administer the drug to cells grown in culture for several days. As a negative control, you culture cells under similar conditions without the drug. You generate cDNA from cells under each condition and label the cDNA with fluorescent tags for use in a microarray—cDNA from drug-treated cells was labeled in red and cDNA from negative control cells labeled in green. To search for genes whose expression was enhanced (increased) by drug treatment, after probing a DNA microarray with your labeled cDNA, you would search for spots on the microarray that fluoresced in:
Red
mRNA degradation
Regulatory molecules can speed up ______ _______
______ __ __ ______ of a gene results in activation of expression of that gene - this is similar to use of a "double negative" in language
Removal of a repressor
the duplicated gene may:
Retain its original function and provide additional quantities of the same product undergo mutation resulting in a beneficial altered protein, thus creating an important new gene be a nonfunctional pseudogene, a remnant of a functional copy of the gene that does not produce a working product
__________ (use of high-frequency sound waves) breaks a genome into pieces approximately 160 kilobases long
Sonication
In 1959, doctors began using the powerful antibiotic methicillin to treat infections of Staphylococcus aureus, but within two years, methicillin-resistant strains of S. aureus (MRSA) appeared. How did the resistant strains of S. aureus emerge?
Staphylococcus aureus bacteria that were able to synthesize cell walls using a protein that was not affected by methicillin survived the methicillin treatments and reproduced at higher rates than did other individuals. Over time, these resistant individuals became increasingly common. Evolutionary change comes about as the proportion of individuals in the population displaying a particular trait increases from generation to generation.
Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ?
The appendix has a substantial amount of defensive lymphatic tissue.
In the United States today, about half of the corn crop is genetically engineered with a protein that is toxic to corn borers, an insect pest of corn. Which of the following conditions would be necessary for evolution of resistance to the toxic protein to occur in the corn borer?
The corn borer must have or generate (by mutation) heritable variation in resistance to the toxic protein. The resistant corn borers must survive better or reproduce more than nonresistant corn borers.
Which of the following statements describes the evolution by natural selection of Mycobacterium tuberculosis bacteria in their new environment?
The drug-resistance trait is an adaptation to the environment in which human hosts are medicated with the antibiotic rifampin. Bacterial cells have higher fitness when they are drug resistant in the new environment in which people have been medicated with antibiotics.
A group of small fish live in a lake with a uniformly light-brown sandy bottom. Most of the fish are light brown, but about 10% are mottled. This fish species is often prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction of what will happen to this fish population?
The proportion of mottled fish will increase over time. The mottled fish will tend to escape predation because they are camouflaged against the mottled lake bottom. The mottled fish will most likely produce more offspring.
The new strands are denatured from the template and separated by length
The shortest fragments could be one base longer than the primer strand
Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution?
The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical.
If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing?
These bacteria should be outcompeted and replaced by bacteria that have lost these genes.
Which of the following statements best describes theories?
They are supported by, and make sense of, many observations.
True or false? It would be difficult to assess whether the drug-susceptible or drug-resistant phenotype in a population of Mycobacterium tuberculosis was more fit in an environment without antibiotics.
True In an environment without antibiotics, individual cells probably would not differ in their reproductive rates or their survival. Without the application of the drug (antibiotic), it would be very difficult to analyze any differences—one wouldn't even be able to sort the cells!
True or False: A cell does NOT express all of its genes all of the time
True. Cells are very selective about the genes they express, how strongly they are expressed, and when they are expressed. Gene expression occurs when a gene product is actively being synthesized and used in a cell. Regulation of gene expression s critical to the efficient use of resources and thus survival.
True or False: Translation initiation can be altered.
True. Translation initiation can be altered.
Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?
Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits.
Which of the following statements about VNTRs and DNA fingerprinting is TRUE?
VNTRs are repeated segments of DNA and the number of repeats varies among individuals.
What are the four postulates of natural selection?
Variation in population, heritable variation, selection, differential survival or reproduction
Which one of the following researchers developed a theory of evolution that was very similar to Charles Darwin's?
Wallace
Which of the following statements concerning DNA microarray technology is FALSE?
When cDNAs are added to a DNA microarray, complementary sequences that anneal with oligonucleotides on the microarray must be identified by eye.
translational control
______ ______ allows the cell to prevent the translation of an mRNA molecule that has already been transcribed.
Post-translational control
______ _______ occurs when the cell fails to activate a manufactured protein by chemical modification
Heterochromatin is found in the inactive __________
X chromosome of mammals
genetic homology
_____ ______ is a similarity in the DNA sequence of different species. ex: genetic code
Transcriptional control
______ _____ occurs when the cell does not produce mRNA.
Operon
______ is a unit made up of linked genes that is thought to regulate other genes responsible for protein synthesis.
The chromosome remains condensed and appears as _________, under the microscope. Condensation ___________
a Barr body, physically prevents DNA from being transcribed.
What is a pseudogene?
a gene whose sequence is similar to that of functioning genes but does not produce a functioning product.
Charles Darwin was the first person to propose
a mechanism for evolution that was supported by evidence.
An adaptation is _____.
a trait that gives an organism a reproductive advantage in the current environment Evolutionary adaptations are inherited characteristics that enhance an organism's ability to survive and reproduce in a particular environment.
The replica plating approach to identify mutant cells:
a. grow mutant bacterial colonies on master plates containing a medium with glucose b. transfer cells from each colony to a piece of sterilized velvet c. transfer cells to a plate with a medium containing only lactose. This new plate is called a replica plate d. compare the colonies on the master plate and replicate
The level of expression of different genes can be highly variable because, it
allows cells to respond to environmental changes.
Dideoxynucleotide triphosphate (ddNTPs)
are identical to dNTPs expect that they lack the 3' hydroxyl group
STRs
are small sequences repeated down the length of a chromosome.
The Galapagos Islands were the first place on Earth to _____.
be declared a world heritage site
Tourism on the Galapagos Islands is being restricted by requiring tourists to _____.
be escorted by trained guides at all times
Of the following anatomical structures, which is homologous to the bones in the wing of a bird?
bones in the flipper of a whale
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?
by the principle of convergent evolution by identifying the bones as being homologous structures
The role that humans play in artificial selection is to
choose which organisms breed, and which do not.
Design an experiment using indicator plates to test if E. coli produce β-Galactosidase when both glucose and lactose are present
control plate with NO lactose and glucose experimental plate with just glucose experimental plate with just lactose experimental plate with both glucose and lactose cells on glucose only plate should be white cells on lactose only should be blue this is to see if the lactose needs glucose to produce the beta-galactosidase or if they are dependent of each other in the plate with both glucose + lactose there will only be white cells b/c only using glucose
In addition to the use of dNTPs in the synthesis reactions _____ are also used
ddNTPs
Sequencing begins by
denaturing template DNA The single-stranded DNA is mixed with DNA polymerase, primers, the 4 normal dNTPs, and small amounts of the 4 fluorescently tagged ddNTPS
A challenge to traditional (pre-1860) ideas about species came from embryology, when it was discovered that _____.
embryos of dissimilar organisms, such as sharks and humans, resemble each other Early in development, the similarities among all vertebrate embryos are more apparent than the differences.
The wing of a bat is homologous to the _____ of a whale.
flipper
_____ ______ is important because the originial gene is still functinal and produces a normal product
gene duplication
genes that make up gene families are hyposthesized to have a risen from a common ancestral sequence through
gene duplication
within a species, genes that are extremely similar to each other in structure and function are considered to be part of the same ______ ______
gene family
The paternally and maternally-inherited X-chromosomes are
generally shut down with equal probability
When Darwin wrote On the Origin of Species, he knew very little about the subject of _____, an essential component of evolutionary theory today.
genetics
the complete DNA sequence of an organism is its _______. The human ____ sequence was published in February 2001 as part of the Human _______ Project
genome
_______ provides a list of the genes present in an organism. ________ __________ looks at when those genes are expressed and how their products interact.
genomics, Functional genomics
Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals?
homologous; analogous
Which species is threatening the natural wildlife on the Galapagos Islands?
humans
DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that
humans and chimpanzees share a relatively recent common ancestor.
The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because
humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin.
repeated sequences are _________ and vary among individuals much more than any other type of sequence
hypervariable
Once a genome has ben sequenced, how can we determine which bases constitute genes?
identifying genes is relatively straightforward in prokaryotes but is much more difficult in eukaryotes, who have many noncoding sequences in their genomes Computer programs are used to scan a prokaryotic genome sequence in both directions in order to identify open reading frames (ORFs) - long stretches of sequence that lack a stop codon but are flanked by a star codon and a stop codon
Where are the Solomon Islands located?
in the South Pacific
One of the X chromosomes in each cell of a female is ______________ early in development
inactivated by DNA methylation
Natural selection is based on all of the following except
individuals adapt to their environments and, thereby, evolve.
lactose, the_______ , binds directly to the ____ ________ protein (ex: post-translation control) causing it to release from the operator and ending negative control of the operon
inducer, lac repressor
Developmental homology
is a similarity in embryonic traits ex: is the gill pushes found during embryonic development in chicks, humans, and cats
The group of genes involved in lactose metabolism was thus termed the ____ _____
lac operon
The lacI protein is a ____ ______ ____that prevents transcription of the lac operon by binding to a site called the operator
lac repressor protein
a fourth gene, called ____ was discovered to part of the lac operon
lacA
3 E. coli genes involved in lactose metabolism
lacZ, lacY and lacI
transposable elements
mobile DNA elements
all heterozygotes for a particular X-linked trait will exhibit _______
mosaicism
lacI
mutants are called constitutive mutants because they produce beta-galactosidase and galactoside permeate even when lactose is absent
lacZ
mutants lack functional beta-galactosidase
lacY
mutants lack the membrane protein galactoside permease and so cannot transport lactose into the cell
Jacob and Monod coined the term _______ for a set of coordinately regulated bacterial genes that are transcribed together into one mRNA
operon
Microsatellites
or a simple sequence repeats are repeating units of 1 to 5 bases
Minisatellites
or variable number terminal repeats (VNTRs), are repeating units of 6 to 500 bases
DNA fingerprinting
refers to any technique for identifying individuals on the basis of unique features of their genomes
structural homology
refers to similarities in adult morphologies ex: is the common structural plan found in the bones of the limbs in vertebrates. n may cases traits are similar in different species because the species in question were related to each other by common descent
What kind of protein might lacI encode?
regulatory protein/ repressor protein/ inhibitor protein
Szilard and Monod hypothesized that the lacI gene codes for a ________ that exerts negative control over the lacZ and lacy Y genes. They hypothesized the repressor would bind ________ to the DNA on or near the promoter for the lacZ and lacY genes.
repressor, directly
DNA microarrays, are support to which _____ ______ ______ ______corresponding to all of the genes of an organism are affixed
short single stranded oligonucleotides
eukaryotic genomes have several thousand loci called
short tandem repeats (STRs)
__________ ____________ involves breaking up the genome into a set of overlapping fragments that are sequenced, and these sequences are then put into the correct order
shotgun sequencing
Why does the presence of extinct forms and transitional features in the fossil record support the theory of evolution by natural selection? The presence of extinct forms and transitional features in the fossil record supports the hypothesis that:
species have changed through time
Heterochromatin
stains densely and is generally not transcribed. Any genes in heterochromatin are thus inactivated. orange region on pic
Euchtomatin
stains lightly. It contains DNA that is transcribed into mRNA purple region on pic
What happens when a dideoxyribonucleotide triphosphate (ddNTP) is incorporated into the 3' end of a growing DNA strand by DNA polymerase?
stop elongation of the DNA chain by not being able to form a phosphodiester bond with their 3′‐carbon atom.
chromatin must be drastically remodeled around a ________ to allow transcription
targeted gene
Globin
the coding genes are expressed at different developmental time-points and differ in their affinity for Oxygen
In eukaryotic organisms, genes contain introns, and most of the genome does not code for a product - thus, it is not possible to scan for ORFs
the most effective strategy for identifying genes is to use reverse transcriptase to produce a cDNA version of each mRNA, and sequence a portion of resulting molecule to produce an expressed sequence tag, or EST. ESTs represent protein-coding genes
If two modern organisms are distantly related in an evolutionary sense, then one should expect that
they should share fewer homologous structures than two more closely related organisms.
Which of the following sets of animals are likely to be found on the Galapagos Islands?
tortoises, finches, blue-footed boobies
The ______ cat is a common example of mosaicism. While multiple genes contribute to feline coat-color, the gene responsible for this phenotype is ______ and has an orange and black allele
tortoiseshell, X-linked
the lacZ, lacY and lacA genes are
transcribed together and are thus coordinately regulated
What 3 forms of gene expression in bacteria?
transcriptional control ,translational control, post-translational control
Scientists studying evolution on the Solomon Islands described which animal as the 'poster child' for the biological species concept?
white-eye bird
