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40 Cards in this Set
- Front
- Back
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What kinds of evidence demonstrate that differentiated cells in a plant or animal retain their full genetic potential?
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For example, a single cell removed from a carrot’s root and placed in a growth medium may begin dividing and eventually grow into an adult plant, or clone. This plant cloning shows that a mature plant cell can dedifferentiate and then redifferentiate to give rise to all the specialized cells of a new plant. The same principal is demonstrated through regeneration in animals. When a salamander loses a leg, certain cells in the leg stump reverse their differentiated state, divide, and then redifferentiate to give rise to a new leg.
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What is the difference between oncogenes and proto-oncogenes? How does one turn into the other? What purpose do proto-oncogenes serve?
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Oncogenes are genes that cause cancer while proto-oncogenes are normal genes with the potential to become cancer-causing oncogenes. A mutation or virus must occur in the cell’s DNA in order for a proto-oncogene to become an oncogene. Proto-oncogenes are necessary for normal control of cell division.
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A muttion in a single gene may cause a major change in the body of a fruit fly, such as an extra pair of legs or wings. Yet it takes the combined action of many genes to produce a wing or leg. How can a change in just one gene cause such a big change in the body? What are such genes called?
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These genes are called homeotic genes, and they are master control genes that regulate many other genes that actually create the anatomical identity of parts of the body during embryonic development.
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If your nerve cells have exactly the same genes, how can they be so different?
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Although nerve cells and skin cells have exactly the same genes, each cell type must be expressing certain genes that are not expressed in the other cell type which causes them to be so different.
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In making recombinant DNA, what is the benefit of using a restriction enzyme that cuts DNA in a staggered fashion?
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In making recombinant DNA, it is beneficial to use a restriction enzyme that cuts DNA in a staggered fashion because such an enzyme creates DNA fragments with “sticky ends,” single-stranded regions whose unpaired bases can hydrogen-bond to the complementary sticky ends of other fragments created by the same enzyme.
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Could two pieces of DNA with different nucleotide sequences produce the same RFLP pattern? Why or why not?
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Two pieces of DNA with different nucleotide sequences could produce the same RFLP pattern depending on if they affect restriction sequences. If the nucleotide differences are not part of any recognition sequences, the two pieces of DNA will produce the same RFLP pattern. If the nucleotide differences affect one or more restriction sequences, the RFLP patterns will be different.
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Why are bone marrow stem cels ideally suited as targets for gene therapy?
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Bone marrow stem cells are ideally suited as targets for gene therapy because they multiply throughout a person’s life.
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Why is genetically modifying a human gamete morally different from genetically modifying a human somatic cell? Do you think it's OK to genetically modify a human gamete? Why or why not?
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Modifying a human somatic cell will only affect the individual patient. However, modifying a human gamete will affect an unborn child as well as all of his or her descendents. I do not think it is OK to genetically modify a human gamete. I do not think it would be morally right to attempt to eliminate genetic defects in children and their descendents. I think we should refrain from interfering with the evolution process.
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Why does a founder event favor macroevolution in the founding population?
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A founder event favors macroevolution in the founding population because a small founding population is subject to extensive sampling error in the composition of its gene pool.
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What environmental factor accounts for the relatively high frequency of the sickle-cell allele in tropical Africa?
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The presence of the disease malaria accounts for the relatively high frequency of the sickle-cell allele in tropical Africa.
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What were the two main points in Darwin's The Origin of Species?
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The two main points in Darwin’s The Origin of Species were descent of diverse species from common ancestors and natural selection as the mechanism of evolution.
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Explain why the following statement is incorrect; "Pesticides have created pesticide resistance in insects."
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The statement “Pesticides have created pesticide resistance in insects” is incorrect because an environmental factor does not create new traits such as pesticide resistance, but rather selects among the traits that are already represented in the population.
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Why are amall, isolated populations more likely to undergo speciation than a large one?
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Small, isolated populations are more likely to undergo speciation than large ones because a small gene pool is more likely to be changed substantially by genetic drift and natural selection.
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Compare/contrast macroevolution and microevolution.
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Microevolution is a change in the gene pool of a population, often associated with adaptation; macroevolution is a change in a life-form, such as the origin of a new species, that is noticeable enough to be evident in the fossil record.
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How does the punctuated equilibrium model account for the relative rarity of transitional fossils lin king newer species to older ones?
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The punctuated equilibrium model accounts for the relative rarity of transitional fossils linking newer species to older ones because the time required for speciation in most cases is relatively short compared to the overall duration of the species’ existence. Thus, on the vast geologic time scale of the fossil record, the transition of one species to another seems abrupt.
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To distinguish a particular clade of mammals within the larger clade that corresponds to class Mammalia, why is hair not a useful characteristic?
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Hair is not a useful characteristic to distinguish a particular clade of mammals within the larger clade that corresponds to class Mammalia because hair is a primitive character common to all mammals and cannot be helpful in distinguishing different mammalian subgroups.
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How do penicillins kill certain bacteria?
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Penicillins kill certain bacteria by preventing the bacteria from making cell walls.
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Which organelles of eukaryotic cells probably descended from endosymbiotic bacteria?
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Mitochondria and chloroplasts probably descended from endosymbiotic bacteria.
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What was the hypothesis Stanley Miller was testing with his experiments?
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The hypothesis that Stanley Miller was testing with his experiments was that conditions on the early Earth favored synthesis of organic molecules from inorganic ingredients.
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How do bacteria help restore the atmospheric carbon dioxide required by plants for photosynthesis?
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Bacteria helps restore the atmospheric CO2 required by plants for photosynthesis by decomposing the organic molecules of dead organisms and organic refuse such as leaf litter, the metabolism of bacteria releases carbon from the organic matter in the form of CO2.
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Name 5 products you've used today that come from angiosperms.
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Wheat bread, cotton clothing, a towel, my wooden desk, and apple cider.
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You discover a new species of plant. Under the microscope, you find that it produces flagellated sperm. A genetic analysis shows that its dominant generation has diploid cells. What kind of plant do you have?
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Because this new species of plant produces flagellated sperm and its dominant generation has diploid cells, I can determine that this plant is a fern.
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Why are coal, oil, and natural gas called "fossil" fuels?
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Coal, oil, and natural gas are called “fossil” fuels because they are derived from ancient organisms that did not decay completely after dying.
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Name some adaptations of plants for living on land.
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Some adaptations of plants for living on land include cuticle, stomata, vascular tissue, lignin-hardened cell walls, gametangia, protected embryos, and differentiation of the body into a subterranean root system and stems and leaves above ground.
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What is the name of the phylum to which humans belong? For what anatomical structure is the phylum named? Where in your body is this anatomical structure found?
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The name of the phylum to which humans belong is chordata. This phylum is named for the notochord. This is found in the human body in cartilage disks between your vertebrae.
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What embryonic stage is common to the development of all animals?
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Blastula is the embryonic stage common to the development of all animals.
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What 4 features do we share with invertebrate chordates such as lancelets?
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Four features we share with invertebrate chordates are a dorsal, hollow nerve chord; notochord; gill structures at some time during development; and post-anal tail at some time during development.
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What role does a long period of parenteral care play in culture?
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A long period of parental care extends opportunity for parents to transmit the lessons of the past to offspring.
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Name several abiotic factors that might affect the community of organisms living inside a home fish tank.
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Abiotic factors that might affect the community of organisms living inside a home fish tank include light, water, temperature, and chemicals added.
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What 2 values would you need to know to figure out the human population density of your community?
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You would need to know the number of people and the land area in which they live to figure out the human population density of your community.
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Why does the set of evolutionary adaptations characterizing a species tend to limit geographic distribution of that species?
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The set of evolutionary adaptations characterizing a species tends to limit the geographic distribution of that species because, to the extent that the species is adapted to particular environmental conditions, it is not so well equipped to survive and reproduce where there are different conditions to which the species is not adapted.
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How does the age structure of the U.S. population explain the current surplus in the Social Security fund? If the system is not changed, why will the surplus give way to a deficit sometime in the next few decades?
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The age structure of the U.S. population explains the current surplus in the Social Security fund because the largest population segment, the boomers, are currently in the work force in their peak earning years, paying into the system. If the system is not changed, the surplus will give way to a deficit sometime in the next few decades because the boomers will retire over the next few decades and begin drawing from the system at a time when there will be fewer employees paying into Social Security.
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How can a keystone predator help maintain species diversity within a population?
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A keystone predator can help maintain species diversity within a population by preying on the dominant competitor.
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According to the energy pyramid model, why is eating grain-fed eef a relatively inefficient means of obtaining the energy trapped by photosynthesis?
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According to the energy pyramid model, eating grain-fed beef is a relatively inefficient means of obtaining the energy trapped by photosynthesis because only 10% of the energy trapped by photosynthesis is turned into biomass by the plant, and only 10% of that energy is turned into meat of a grazing animal, so eating grain-fed beef obtains only about 1% of the energy of photosynthesis.
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What would happen to the carbon cycle if all the detrtivores suddenly went o "strike" and stopped working?
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If all the detritivores suddenly went on “strike” and stopped working, carbon would accumulate in organic mass, the atmospheric reservoir of carbon would decline, and plants would eventually be starved for CO2.
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How could a community apear to have realtively little diversity even though it is rich in species?
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A community could appear to have relatively little diversity even though it is rich in species if one or a few of the diverse species accounted for almost all the organisms in the community, with the other species being rare.
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What is an introduced species? Why are introduced species often able to outcompete natvie organisms?
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An introduced species is a species that has been accidentally or intentionally transferred by humans from one location to another location where it does not occur naturally. Introduced species usually have relatively few pathogens, parasites, and predators to slow population growth and so may outcompete native organisms for resources.
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What is the greenhouse effect? How could the greenhouse effect be related to global warming?
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The slowing of the heat escaping from Earth due to Carbon dioxide and other gases in the atmosphere absorbing infrared radiation is the greenhouse effect. As the carbon dioxide concentration in the atmosphere increases, more heat is retained, which could account for global warming.
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Why is fragmentation of populations of endangered species increasing?
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The fragmentation of populations of endangered species is increasing because, by destroying habitat, human activities are fragmenting the populations of many species into subpopulations that live in the separate patches of habitat that remain.
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What are the 3 main causes of the biodiversity crisis?
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Three main causes of the biodiversity crisis include habitat destruction, introduced species, and overexploitation.
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