Biology Questions
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Parsimony suggests that parental care in birds, crocodiles, and some dinosaursa. evolved independently multiple times by convergent evolution.b. evolved once in an ancestor common to all three groups.c. is a homoplastic trait.d. is not a homologous trait.
Natural selection can lead to speciationa. by causing small populations to diverge more than large populations.b. because the evolutionary changes that two populations acquire while adapting to different habitats may have the effect of making them reproductively isolated.c. by favoring the same evolutionary change in multiple populations.d. by favoring intermediate phenotypes.
Sieve tubes and sieve elements area. homoplastic because they have different function.b. homologous because they have similar function.c. homoplastic because their common ancestor was single-celled.d. structures involved in transport within animals.
Plate tectonics can contribute toa. volcanoes and earthquakes.b. formation of supercontinents.c. increased weathering and CO2 sequestration.d. All of the choices are correct.
The forelimb of a bird and the forelimb of a rhinocerosa. are homologous and symplesiomorphic.b. are not homologous but are symplesiomorphic.c. are homologous and synapomorphic.d. are not homologous but are synapomorphic.
In order to determine polarity for different states of a charactera. there must be a fossil record of the groups in question.b. genetic sequence data must be available.c. an appropriate name for the taxonomic group must be selected.d. an outgroup must be identified.
Problems with the biological species concept include the fact thata. many species reproduce asexually.b. postzygotic isolating mechanisms decrease hybrid viability.c. prezygotic isolating mechanisms are extremely rare.d. All of the choices are correct.
Natural selection cana. enhance the probability of speciation.b. enhance reproductive isolation.c. act against hybrid survival and reproduction.d. All of the choices are correct.
Speciation by allopolyploidya. takes a long time.b. is common in birds.c. leads to reduced numbers of chromosomes.d. occurs after hybridization between two species.
Hybridization between incompletely isolated populationsa. always leads to reinforcement due to the inferiority of hybrids.b. can serve as a mechanism for preserving gene flowbetween populations, thus preventing speciation.c. occurs only in plants.d. never affects rates of speciation.
Overall similarity of phenotypes may not always reflect evolutionary relationshipsa. due to convergent evolution.b. because of variation in rates of evolutionary change of different kinds of characters.c. due to homoplasy.d. All of the choices are correct.
The principle of parsimonya. helps evolutionary biologists distinguish among competing phylogenetic hypotheses.b. does not require that the polarity of traits be determined.c. is a way to avoid having to use outgroups in a phylogenetic analysis.d. cannot be applied to molecular traits.
Character displacementa. arises through competition and natural selection, favoring divergence in resource use.b. arises through competition and natural selection, favoring convergence in resource use. c. does not promote speciation.d. reduced speciation rates in Galápagos finches.
Cladisticsa. is based on overall similarity of phenotypes.b. requires distinguishing similarity due to inheritance from a common ancestor from similarity for other reasons. c. is not affected by homoplasy.d. None of the choices is correct.
During the history of life on Eartha. there have been major extinction events.b. species diversity has steadily increased.c. species diversity has stayed relatively constant.d. extinction rates have been completely offset by speciation rates.
Allopatric speciationa. is less common than sympatric speciation.b. involves geographic isolation of some kind.c. is the only kind of speciation that occurs in plants.d. requires polyploidy.
Prezygotic isolating mechanisms include all of the following excepta. hybrid sterility.b. courtship rituals.c. habitat separation.d. seasonal reproduction.
Leopard frogs from different geographic populations of the Rana pipiens complex a. are members of a single species because they look very similar to one another. b. are different species shown to have pre- and postzygotic isolating mechanisms. c. frequently interbreed to produce viable hybrids.d. are genetically identical due to effective reproductive isolation.
Genetic drift and natural selection can both lead to rapid rates of evolution. However,a. genetic drift works fastest in large populations.b. only drift leads to adaptation.c. natural selection requires genetic drift to produce new variation in populations.d. both processes of evolution can be slowed by gene flow.Answer
Homologous structuresa. are structures in two or more species that originate as the same structure in a common ancestor.b. are structures that look the same in different species.c. cannot serve different functions in different species.d. must serve different functions in different species.