Q&A Hero

Q: Read the following scenario to answer the following question(s). Malaria is a disease caused by parasitic protists in the genusPlasmodium. The parasite is transmitted to humans by female Anopheles mosquitoes. ThePlasmodium parasite feeds on human red blood cells, eventually destroying them. Humans infected with malaria can exhibit many symptoms. Depending on the severity of the infection, these can range from fever, chills, sweating, and headaches to anemia and kidney failure. Ultimately, malaria can result in death. However, if time and money permit, once a person is infected, they can be treated with different antimalarial drugs. Two commonly used drugs are artemisinin and quinine. In addition, one way to prevent the spread of malaria is to apply pesticides to treat areas with Anopheles mosquitoes. The National Malaria Eradication Program began work in 1947 with the goal of eliminating malaria from the southern United States. In 1947, 15,000 cases of malaria were reported nationwide. By 1950, only 2,000 cases were reported, and by 1951, malaria was considered eradicated from the United States. Today, the disease is most common in Africa and South America, two continents that are highly impoverished. About one million people die from malaria every year, many of them children. In Africa, it is estimated that one in every five childhood deaths is due to malaria. Plasmodium illustrate feeding characteristics of a(n) ________. A) slime mold B) ciliate C) apicomplexan D) algae

Q: Read the following scenario to answer the following question(s). Malaria is a disease caused by parasitic protists in the genusPlasmodium. The parasite is transmitted to humans by female Anopheles mosquitoes. ThePlasmodium parasite feeds on human red blood cells, eventually destroying them. Humans infected with malaria can exhibit many symptoms. Depending on the severity of the infection, these can range from fever, chills, sweating, and headaches to anemia and kidney failure. Ultimately, malaria can result in death. However, if time and money permit, once a person is infected, they can be treated with different antimalarial drugs. Two commonly used drugs are artemisinin and quinine. In addition, one way to prevent the spread of malaria is to apply pesticides to treat areas with Anopheles mosquitoes. The National Malaria Eradication Program began work in 1947 with the goal of eliminating malaria from the southern United States. In 1947, 15,000 cases of malaria were reported nationwide. By 1950, only 2,000 cases were reported, and by 1951, malaria was considered eradicated from the United States. Today, the disease is most common in Africa and South America, two continents that are highly impoverished. About one million people die from malaria every year, many of them children. In Africa, it is estimated that one in every five childhood deaths is due to malaria. If an area infested with female Anopheles mosquitoes is treated with pesticides, and these mosquitos live, continue to breed, and continue to spread malaria, what can we conclude? A) Alleles that are resistant to the pesticides are being selected for, so female Anopheles mosquitoes may continue to infect humans. B) Malaria is not actually caused by thePlasmodium parasite. C) Male Anopheles mosquitoes are also carriers of thePlasmodium parasite. D) The people are becoming resistant to the pesticide.

Q: If you were to view this organism with the right microscope you could see that the entire stalk is covered with smaller hairs than the ones on the opening. What might be the function of these smaller hairs on the stalk? A) camouflage B) movement C) aerobic respiration D) spore production

Q: In the image above, the aquatic organism moves using flagella. It is parasitic and can colonate and reproduce in the human intestine. What type of organism could this be? A) a protozoan B) a slime mold C) phytoplankton D) seaweed

Q: What kind of protist is this? A) ciliate B) plasmodial slime mold C) flagellate D) foram

Q: What kind of prokaryotes are these? A) bacilli B) spirochetes C) cocci D) ciliates

Q: According to this evolutionary tree, the archaea and eukaryotes last shared a common ancestor ________. A) 1.0 billion years ago B) 1.75 billion years ago C) 2.5 billion years ago D) 3.5 billion years ago

Q: Which of the following is a plausible reason for why it may be difficult to treat infections that arise from tooth decay? A) Biofilm bacteria that cause tooth decay begin to produce endospores as a means to deter effects of antibiotics. B) Binary fission in biofilm bacteria that cause tooth decay begins to decrease as the biofilm community becomes more complex, thereby producing fewer bacterial cells for antibiotics to penetrate. C) As the biofilm that causes tooth decay becomes larger, its structure makes it difficult for antibiotics to break through bacterial cell walls. D) Bacteria of the biofilm that cause tooth decay form a symbiotic relationship with the antibiotics and therefore diminish antibiotic effectiveness.

Q: Endosymbiosis explains the origin of the ________ of eukaryotes. A) chloroplasts and mitochondria B) endomembrane system C) nuclear envelope D) membrane-bound organelles

Q: What accounts for the similarity between seaweeds and plants? A) Plants are the ancestors of seaweeds. B) convergent evolution C) evolutionary fitness D) Seaweeds are aquatic plants.

Q: Which of the following is a colonial form of green algae? A) Volvox B) Giardia C) Paramecium D) Plasmodium

Q: A photoautotrophic unicellular organism with a shell made of silica is most likely a(n) ________. A) apicomplexan B) foram C) dinoflagellate D) diatom

Q: ________ are responsible for toxic red tides. A) Plasmodial slime molds B) Dinoflagellates C) Red algae D) Diatoms

Q: Which of the following are most closely related to plants? A) brown algae B) red algae C) slime molds D) green algae

Q: ________ include cells that can function either independently or as a single unit. A) Dinoflagellates B) Forams C) Seaweeds D) Cellular slime molds

Q: Which protozoan group consists solely of parasitic forms? A) apicomplexans B) ciliates C) flagellates D) amoebas

Q: You discover a unicellular organism that moves by what appear to be pseudopodia. You conclude that this organism is ________. A) either a type of amoeba or a type of slime mold B) a type of bacterium C) a type of alga D) either a type of ciliate or a type of apicomplexan

Q: Flagellates, amoebas, apicomplexans, and ciliates are all what type of protist? A) slime molds B) protozoans C) dinoflagellates D) seaweeds

Q: According to the theory of endosymbiosis, which organelles evolved from small prokaryotes that established residence within other, larger prokaryotes? A) vacuoles and lysosomes B) Golgi apparatus and endoplasmic reticulum C) centrioles and ribosomes D) mitochondria and chloroplasts

Q: Eukaryotes that are not fungi, animals, or plants are classified in a "catch-all" category called ________. A) archaea B) bacteria C) seaweeds D) protists

Q: Recent scientific studies of the impact of microbiota on the amount of fat versus lean body mass (i.e., body composition) are described in your text. How do those studies illustrate the importance of microbiota communities in our bodies? A) If transferred to lean humans, intestinal microbiota of obese humans will cause obesity. B) If transferred to obese humans, intestinal microbiota in lean humans will cause exaggerated obesity. C) The studies suggest that mice are an unreliable model organism to use for studies of human intestinal microbiota and obesity. D) The studies suggest that intestinal microbiota may be involved in regulating our digestive processes.

Q: Approximately 1015% of insect species harbor bacteria that make needed nutrients available to the insects. How might you classify these bacteria? A) phytoplankton B) extremophiles C) exotoxins D) endosymbionts

Q: In Yellowstone National Park, hot springs can reach temperatures of 205F (96C). Despite these high temperatures, Aquifex bacteria flourish. How might you classify Aquifex bacteria? A) slime molds B) extremophiles C) amoebas D) algae

Q: ________ is an example of bioremediation. A) Cyanobacteria converting atmospheric nitrogen to a form that plants can use B) The use of an autoclave to kill endospores C) The use of prokaryotes to treat sewage D) A dinoflagellate bloom causing massive fish kills

Q: In the soil, some ________ help to decompose dead organisms and other waste materials, returning vital chemical elements such as nitrogen to the environment. A) slime molds B) animals C) protozoans D) prokaryotes

Q: Food poisoning from Salmonella occurs because of ________. A) an exotoxin secreted by Salmonella bacteria B) an endotoxin produced by Salmonella bacteria C) easy transmission between people living in close contact D) extremophile conditions

Q: Which of the following include the two classes of poisons produced by pathogenic bacteria? A) exotoxins and endotoxins B) chemoautotrophs and chemoheterotrophs C) protozoans and fungi D) bacilli and cocci

Q: All organisms that photosynthesize fit into which nutritional category? A) mixotroph B) heterotrophs C) autotrophs D) parasites

Q: Trichomonas vaginalis is a protozoan that feeds on white blood cells and bacteria living on the cells lining the female human vagina, thereby creating a common sexually transmitted disease often known as "trich."The feeding mechanism of this protozoan makes it a ________. A) parasite B) autotroph C) producer D) mixotroph

Q: Under ideal conditions, prokaryotes are capable of reproducing at a(n) ________ rate. A) negative B) exponential C) infinite D) variable

Q: Prokaryotes reproduce by means of ________. A) mitosis B) binary fission C) budding D) meiosis

Q: Which of the following would likely be the most difficult to kill if you were you to can your own food? A) streptococci B) endospores C) biofilms D) staphylococci

Q: Bacilli are ________ prokaryotes. A) spherical B) comma-shaped C) rod-shaped D) spiral

Q: Spherical bacteria that occur in clusters are ________. A) streptococci B) bacilli C) spirochetes D) staphylococci

Q: Which of the following prokaryotes aid digestion in cattle, deer, and other animals that obtain nutrition from cellulose? A) halophiles B) dinoflagellates C) methanogens D) cocci

Q: The prokaryotic group that tends to inhabit extreme environments belongs to ________. A) Protista B) Archaea C) Euglena D) Bacteria

Q: Which prokaryotic group is most closely related to eukaryotes? A) Bacteria B) Protista C) Archaea D) Bacteria and Archaea are equally closely related.

Q: Variation among pre-cells was due to ________. A) genetic drift B) natural selection C) the bottleneck effect D) mutation

Q: RNAs that can act as enzymes are called ________. A) ribozymes B) ATPs C) lysosomes D) prokaryotes

Q: Why is RNA thought to have been the first genetic material? A) RNA is structurally simpler than DNA. B) RNA has been found on meteorites. C) RNA is capable of self-replication D) Primitive organisms, such as some viruses, have RNA as their genetic material.

Q: Read the following scenario to answer the following questions. As part of a semester-long biology field research course, you are studying reproductive barriers among four different frog species. Your goal is to determine what type of reproductive barrier likely causes the gene pools of the four different frog species to be isolated. These four species share common geographic habitats and are both anatomically and gametically compatible. Your research professor gives you the following figure to consider. After studying the figure, answer the questions that follow. What can you conclude about the breeding characteristics of these four frog species? A) The maximum mating activity of the four frog species at different times reduces and/or removes interbreeding. B) The minimum mating activity of the four frog species at different times reduces and/or removes interbreeding. C) The average mating activity of the four frog species at different times reduces and/or removes interbreeding. D) The individual mating activity of each of the four frog species at the beginning of their mating periods reduces and/or removes interbreeding.

Q: Read the following scenario to answer the following questions. As part of a semester-long biology field research course, you are studying reproductive barriers among four different frog species. Your goal is to determine what type of reproductive barrier likely causes the gene pools of the four different frog species to be isolated. These four species share common geographic habitats and are both anatomically and gametically compatible. Your research professor gives you the following figure to consider. After studying the figure, answer the questions that follow. Based on the independent and dependent variables represented in the figure and the information you have about common geographic habitats as well as anatomical and gametic compatibility of the four frog species, you initially conclude that reproductive barriers may be due to ________. A) habitat isolation B) mechanical isolation C) temporal isolation D) gametic isolation

Q: Read the following scenario to answer the following questions. As part of a semester-long biology field research course, you are studying reproductive barriers among four different frog species. Your goal is to determine what type of reproductive barrier likely causes the gene pools of the four different frog species to be isolated. These four species share common geographic habitats and are both anatomically and gametically compatible. Your research professor gives you the following figure to consider. After studying the figure, answer the questions that follow. If the researchers of this study wanted to collect reliable data about natural behavior, which methodology should they choose? A) The researchers collected multiple male and female frogs from each species and studied them in a lab environment to determine their normal breeding seasons. B) The researchers studied multiple male and female frogs from each species in their natural environments to determine their normal breeding seasons. C) The researchers collected multiple male and female frogs from each species, mixed males and females from each species, and studied the mixed pairs in a lab environment to determine their normal breeding seasons. D) The researchers studied one male and female frog from each species in their natural environments to determine their normal breeding seasons.

Q: Read the following scenario to answer the following questions. In some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." Male ligers are sterile but some female ligers are fertile. In the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. Furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. The production of sterile male ligers is an example of ________. A) sympatric speciation B) the founder effect C) a postzygotic barrier D) a prezygotic barrier

Q: Read the following scenario to answer the following questions. In some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." Male ligers are sterile but some female ligers are fertile. In the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. Furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. The natural differences in the ranges of wild tigers and lions is an example of ________. A) a prezygotic barrier B) a postzygotic barrier C) the impact of mutations D) sympatric speciation

Q: Read the following scenario to answer the following questions. In some zoos, rare crosses between a male lion and a female tiger have produced hybrid offspring called "ligers." Male ligers are sterile but some female ligers are fertile. In the wild, lion and tiger ranges do not naturally overlap, making such a cross unlikely. Furthermore, the solitary behavior of tigers and the social organizations of lions create behavioral differences. Applying the biological species concept, the sterility of ligers reveals that ________. A) a new species called "ligers" is forming B) tigers and lions are actually the same species C) tigers and lions are separate species D) lions are probably a subspecies of tigers

Q: Examine the figure below. According to the figure, cladistic analysis indicates that crocodiles are more closely related to ________ than to ________. A) birds... pterosaurs B) snakes... birds C) Ornithischian dinosaurs pterosaurs D) birds... lizards

Q: Examine the evolutionary relationships represented in the following figure. Based upon this diagram, the two most closely related species are ________. A) leopards and striped skunks B) leopards and European otters C) European otters and coyotes D) coyotes and wolves

Q: Examine the two squirrel populations in the following figure. The populations are separated by a geographic barrier. If after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? A) Hybrid offspring of the two populations begin to appear. B) The two populations are not interbreeding freely. C) One species will increase into a population size twice as large as the other species. D) Polyploidy is creating new species.

Q: Why is it INCORRECT to assume that mass extinctions carry only negative impact on the evolution of life on Earth? A) Mass extinctions are sometimes followed by periods of evolutionary change when other organism groups can flourish and expand in diversity and size. B) Mass extinctions enable scientists to better study embryonic development in two species of organisms and therefore identify possible homology. C) Mass extinctions enable scientists to better study paedomorphosis. D) Mass extinctions disprove Darwin's theory of evolution.

Q: What hypothesis did Luis and Walter Alvarez test in relation to the mass extinction of dinosaurs 65 million years ago (MYA)? A) The mass extinction 65 MYA was caused by a surge of catastrophic cyclones. B) The mass extinction 65 MYA was caused by a slow but steady increase in climate temperatures. C) The mass extinction 65 MYA was caused by an impact of an extraterrestrial object. D) The mass extinction 65 MYA was caused by the loss of preferred plants for food.

Q: When you go outside, it is common to hear a variety of bird songs. These songs vary among bird species as well as bird flocks. Interestingly, some bird species that are highly unrelated have very similar song qualities. What can you conclude from this phenomenon? A) The bird songs are homologous traits. B) The bird songs have achieved speciation after coming from allopatric species. C) The bird songs are analogous traits. D) The bird songs have different molecular DNA.

Q: Which one of the following is the only domain that contains eukaryotes? A) Animalia B) Plantae C) Archaea D) Eukarya

Q: An ancestral species and all its evolutionary descendants define a(n) ________. A) outgroup B) clade C) genus D) ingroup

Q: Molecular systematics might examine all of the following types of data EXCEPT ________. A) proteins B) DNA sequences C) amino acid sequences D) anatomical features

Q: Analogous structures are evidence of ________. A) common ancestry B) divergent evolution C) stabilizing selection D) convergent evolution

Q: Homology is evidence of ________. A) convergent evolution B) polyploidy C) common ancestry D) paedomorphosis

Q: The wing of a penguin is ________ the wing of a butterfly. A) structurally identical to B) superior to C) homologous to D) analogous to

Q: The wing of a bald eagle is ________ the wing of a penguin. A) convergent with B) homologous to C) unrelated to D) analogous to

Q: Of the following taxonomic levels, species found within the same ________ are the most closely related. A) family B) phylum C) order D) domain

Q: Which of the following taxonomic levels is most inclusive? A) order B) genus C) family D) class

Q: The science of naming, identifying, and classifying organisms is called ________. A) biogeography B) systematics C) phylogeny D) taxonomy

Q: ________ is the discipline of biology that focuses on classifying organisms and determining their evolutionary relationships. A) Taxonomy B) Evo-devo C) Systematics D) Biogeography

Q: A period of mass extinction is often followed by ________. A) explosive diversification B) paedomorphosis C) global warming D) continental drift

Q: Dinosaurs (aside from the lineage that produced birds) were extinct by the end of the ________. A) Cretaceous B) Silurian C) Eocene D) Permian

Q: Characid fishes are found naturally only in South America and Africa. Fossils of these fish are not found on any other continents. What is the most likely explanation of this distribution pattern? A) These fishes arose in either Africa or South America and migrated across the South Atlantic Ocean to the other continent. B) Characid fishes arose prior to the separation of the African and South American continents. C) Characid fishes arose in the South Atlantic Ocean and migrated to Africa and South America. D) Convergent evolution is responsible for the distribution of characid fishes.

Q: The Permian mass extinction is associated with ________. A) an asteroid impact B) global warming C) the formation of Pangaea D) the diversification of mammals

Q: Plate tectonics has been responsible for instances of all of the following EXCEPT ________. A) volcanic explosions B) sympatric speciation C) allopatric speciation D) mass extinction

Q: Uranium-235, with a half-life of 713,000,000 years, decays to lead-207. If a rock sample is determined to have one-quarter of the uranium-235 content it had when it formed, the age of the rock sample can be estimated to be approximately ________ years old. A) 178 million B) 713 million C) 28.5 billion D) 1.4 billion

Q: The current geological era is the ________. A) Paleozoic B) Cenozoic C) Mesozoic D) Cambrian

Q: Which of the following would be an example of paedomorphosis? A) starfish regenerating severed limbs B) rapid evolution in a small, isolated population C) two species evolving a similar appearance D) insects that can reproduce in larval stages without reaching mature development stages

Q: Feathers in birds appear to have first evolved for insulation but later conveyed a new advantage in helping create light aerodynamic surfaces. This switch in function is an example of a(n) ________. A) paedomorphosis B) an analogy C) an adaptation D) exaptation

Q: Some fish have bony fins. If the body of water they are in dries out, these fins can be used to help the fish "walk" to another body of water. In this context, bony fins are an example of ________. A) an exaptation B) an adaptation C) a macroevolutionary event D) paedomorphosis

Q: Sympatric speciation specifically EXCLUDES ________. A) behavioral isolation B) postzygotic barriers C) geographic isolation D) temporal isolation

Q: Which of the following describes allopatric speciation? A) A population of squirrels is separated by the Grand Canyon. The two subpopulations evolve into two distinct species. B) A tetraploid plant species evolves from a diploid ancestor. Both the tetraploid and diploid species are found in the same habitat. C) One population breeds in the fall; another population breeds in the spring. D) A male horse and a female donkey mate, producing a sterile hinny.

Q: Speciation requires ________. A) periods of rapid evolutionary change B) geographic isolation C) long periods of time D) genetic isolation

Q: When two frog species, Rana pipiens and Rana sylvatica, mate, the offspring die early in embryonic development. This is an example of ________. A) hybrid sterility B) mechanical isolation C) reduced hybrid viability D) reduced hybrid fertility

Q: The type of reproductive barrier that occurs when two species mate but produce sterile hybrids is referred to as ________. A) mechanical isolation B) temporal isolation C) a postzygotic barrier D) a prezygotic barrier

Q: What type of reproductive isolating mechanism is described by a situation in which female fireflies mate only with males who emit light in a particular pattern? A) habitat isolation B) temporal isolation C) mechanical isolation D) behavioral isolation

Q: A reproductive barrier that prevents individuals from closely related species from interbreeding is an example of ________. A) a prezygotic barrier B) allopatric speciation C) sympatric speciation D) geographic isolation of populations