BIO 1M03 Exam Review Questions With Correct Answers

1. Darwin described evolution using the phrase "descent with modification." Please select the response that describes most accurately from a modern perspective what the phrase entails. A) Evolution takes a long time - it is a gradual process - and produces decent results. B) Evolution is a natural phenomenon that is ongoing, changing individuals even today. C) Closely related species are similar at the genetic, developmental, and structural levels. D) Populations living today are identical to populations that lived in the past. - Answer Closely related species are similar at the genetic, developmental, and structural levels. Please select the response that presents the most-accurate statement. A) Mycobacterium tuberculosis populations can evolve drug resistance over time. B) Evolution by natural selection involves variation among individuals. C) If all individuals in a population were to survive equally effectively, then natural selection would operate to favour individuals who produce the most offspring. D) Between 1976 and 1978, a finch population in the Galápagos Islands adapted to drought conditions. E) All other responses are correct. - Answer All other responses are correct. Imagine that you were conducting fieldwork on Daship Island, whereon temperature had started to increase year after year; please select the response that states whether evolutionary biologists would expect natural selection to operate as a consequence from this change and explains most accurately why. A) Yes, because mutations would be expected to occur more frequently in hotter environments. B) Yes, because traits that allow individuals to survive and reproduce more effectively in hotter environments would be expected to increase in frequency. C) No, because the environment always is changing, so the increase in temperature would constitute nothing new. D No, because the only change that might manifest would be for organisms from other, colder environments to move to the hotter conditions on the island. E) Yes, because individuals would be expected to adapt to the hotter conditions and pass traits acquired during th - Answer Yes, because traits that allow individuals to survive and reproduce more effectively in hotter environments would be expected to increase in frequency. A two-allele locus known as gene hackman is studied in a snail population that is in Hardy-Weinberg equilibrium. The frequency for the dominant phenotype is 99%. The frequency for q is A) 0.9 B) 0.81 C) 0.18 D) 0.1 E) 0.01 - Answer 0.1 Sediment analysis shows that some areas in Cootes Paradise formerly were connected by streams; those particular streams dried up over the past decade, leaving microscopic 'water-bears' populations in 'suspended animation;' after being revived, individuals from the populations were mated with each other and produced offspring with equivalent fitness to their parents, so were assigned to the same taxon. Please select the response that presents the most-appropriate process or concept to explain the observation. A) vicariance B) dispersal C) biological species concept D) morphological species concept E) phylogenetic species concept - Answer biological species concept Please consider the cartoon that is presented below and state, by providing a name, whose view on organisms is presented and, by providing one word, what type of thinking it involved; you might, for instance, put name: Plato thinking: typological name: ______________ thinking: ______________ - Answer Darwin/Wallace population Darwin described evolution with the phrase "descent with modification." Please select the response that describes most accurately from a modern perspective what the phrase entails. A) Evolution takes a long time - it is a gradual process - and produces decent results. B) Evolution is a natural phenomenon that is ongoing, changing individuals even today. C) All species are identical at the genetic, developmental, and structural levels. D) Populations living today are related (genetically) to populations that lived in the past, but they are non-identical. - Answer Populations living today are related (genetically) to populations that lived in the past, but they are non-identical. BIOLOGY 1M03 student Kate Selegshun (Nate's sister) observes that females in a water bear species prefer males that have much longer stylets (mouth parts) and all males have much longer stylets than do females. This process underlying the observed pattern most likely involves: Question options: a)sexual selection. b)-93 c)remedied by applying urine. d) disassortative mating. e) assortative mating. - Answer sexual selection BIOLOGY 1M03 student Nate Selegshun observes that short-spined females in a sea urchin species prefer males that are characterised by short spines and long-spined females prefer long-spined males. The phenomenon is known as: Question options: a) disassortative mating. b) inbreeding. c) sexual selection. d) assortative mating. e) genetic surfing. - Answer assortative mating. Imagine a human population wherein Human Immunodeficiency Virus (HIV) infection were common and several alleles were to reside at the locus for gene Simmons, which affects resistance to HIV infection; one allele, S4, were to confer highest resistance; and you were to genotype many individuals. Please predict by selecting the most-accurate response how observed genotype frequencies would compare to genotype frequencies expected under Hardy-Weinberg equilibrium conditions. A) Because human populations are so large, genotypes automatically would be in Hardy-Weinberg equilibrium proportions. B) Too few S4 homozygotes would be present. C) More heterozygous than homozygous genotypes containing S4 must be present. D) Allele S4 would be present at a greater frequency than expected under Hardy-Weinberg equilibrium. E) The frequency for allele S4 would equal p4. - Answer Allele S4 would be present at a greater frequency than expected under Hardy-Weinberg equilibrium. In human populations, birth weight depends partially on alleles that occur at multiple gene loci, and babies with intermediate weights are characterised by the greatest survival likelihoods, as Doc Roc informed his sisters after they had given birth to heavy would-be lawyers. Please select the response that summarises the most-likely outcome from natural selection operating on human baby birth weight. Question options: a)Average birth weight would remain the same; total phenotypic variation would remain the same; allele frequencies would remain unchanged. b)Average birth weight would increase; total phenotypic variation would decrease; allele frequencies would change. c)Average birth weight would decrease; total phenotypic variation would remain the same; allele frequencies would remain unchanged. d)Average birth weight would remain the same; total phenotypic variation would increase; allele frequencies would remain - Answer Average birth weight would remain the same; total phenotypic variation would decrease; allele frequencies would change. BIOLOGY 1M03 student Evan Lushon (Eve's brother) analyses a gene locus in two distinct squirrel populations, occupying adjacent territories on McMaster University campus; population 1 contains many individuals and is characterised by large genetic diversity; population 2 contains few individuals, all homozygous for an allele that is absent in population 1. The process underlying the observed pattern most likely involves: Question options: a) urination. b) founder events followed by genetic drift c) founder events. d) a population bottleneck that separated a single large population into two. e) a genetic bottleneck in population 2. - Answer a genetic bottleneck in population 2. Imagine a population wherein two alleles for the B gene locus were found in the following genotype proportions: B1B1 = 0.33 B1B2 = 0.33 B2B2 = 0.33 Please select the response that presents the expected frequencies for genotypes B1B1; B1B2; B2B2, respectively, in the population assuming that the population could be described as being 'in' Hardy-Weinberg equilibrium. Question options: a) 0.216; 0.497; 0.286 b) 0.073; 0.394; 0.533 c) 0.333; 0.333; 0.333 d) 0.250; 0.500; 0.250 e) 0.370; 0.330; 0.300 - Answer 0.250; 0.500; 0.250 Please consider the wings in bats and birds and select the most-correct response about them. Question options: a) Their wings and insect wings are homologous. b) Their wings are homologous; their limbs represent homoplasy. c) Both have highly modified hand and finger bones; these modifications are homologous. d) Their wings would be represented on a cladogram as two independent character states. e) Both their wings and limbs represent homoplasy. - Answer Their wings would be represented on a cladogram as two independent character states. Please select the response that explains best why a hard-core population geneticist would discount self-reproduction as an evolutionary mechanism. Question options: a) It occurs rarely. b) It has no effect on allele frequencies. c) It reduces fitness. d) It fails to violate the assumptions on which the Hardy-Weinberg equilibrium principle is predicated. e) It has no effect on genotype frequencies. - Answer It has no effect on genotype frequencies. Imagine that you were conducting fieldwork on Daplane Island, whereon rainfall had started to increase year after year; please select the response that states whether evolutionary biologists would expect natural selection to operate as a consequence from this change and explains most accurately why. Question options: a) No, because the only change that might manifest would be for organisms from other, dry environments to move to the wetter conditions on the island. b) Yes, because traits that were acquired by individuals in their lifetimes to survive and reproduce more effectively would be expected to be transmitted to offspring. c) Yes, because past mutations could have produced variation in heritable traits among individuals that could have led to differential survival in wetter environments. d) No, because the environment always is changing, so the increase in rainfall would constitute nothing new. e) Yes, because - Answer Yes, because past mutations could have produced variation in heritable traits among individuals that could have led to differential survival in wetter environments. Sediment analysis shows that some regions in a desert once comprised a large, continuous lake-and-marsh ecosystem; today, it predominantly is dry, with tiny, isolated springs, each spring harbouring its own, microscopic 'water-bear' species. Please select the response that presents the most-appropriate process or concept to explain the observation. Question options: a) phylogenetic species concept b) morphological species concept c) variance d) allopatric speciation e) dispersal - Answer allopatric speciation Please select the response that predicts in accordance with the theory of evolution by natural selection what would happen to beak size and shape in medium ground finches in the Galápagos Islands in the future. Question options: a) Beaks may fluctuate in size and shape, but they will remain roughly constant over the long term. b) Beaks will continue to get deeper and wider. c) Beak changes will occur before changes in the environment to prepare individuals. d) Beaks will continue to get deeper, but they should eventually begin to get narrower. e) Beak changes will depend on the environment, even if Peter and Rosemary Grant retire. - Answer Beak changes will depend on the environment, even if Peter and Rosemary Grant retire. After a large crater was found off the coast near Mexico and dated to have been formed 65 Ma, most biologists became convinced that the impact hypothesis for the end Cretaceous (i.e., K-Pg) extinction was correct. Please select the response that most-accurately describes why the evidence was considered so persuasive. Question options: a) High iridium levels, shocked quartz, and microtektites associated with the crater were consistent with the impact hypothesis. b) The sides lining the crater contained charcoal and soot, evidence that intense heat had been produced at some point in the past. c) Nothing but a gigantic impact could have left a meteorite inside a crater that large. d) The meteorite itself was found at the bottom of the crater. e) The crater contained fossils of giant dinosaurs known as Doc rockyii, which no longer exist. - Answer High iridium levels, shocked quartz, and microtektites associated with the crater were consistent with the impact hypothesis. Imagine a population wherein two alleles for the A gene locus were found in the following genotype proportions: A1A1 = 0.3025A1A2 = 0.495A2A2 = 0.2025 Please select the response that presents the observed proportions for the A1 and A2 alleles, respectively. Question options: a) 0.515; 0.485 b) 0.55; 0.45 c) 0.37; 0.63 d) 0.608; 0.392 e) 0.27; 0.73 - Answer 0.55; 0.45 SINEs are genes that jump from place to place among chromosomes. Using the data that are presented subsequently, please select the response that presents SINEs that provide synapomorphic character states identifying whales and hippos as closest relatives (a "?" indicates uncertainty whether a SINE is present in a species). a) 22, 25, 27, 29 b) 25, 29 c) 21, 28 d) 30 e) none of the above identify only SINES consistent with the 'whippo' hypothesis - Answer no other responses identify only SINES consistent with the 'whippo' hypothesis A two-allele locus known as gene wilder is studied in an orangutan population that is in Hardy-Weinberg equilibrium. The frequency for the dominant phenotype is 99%. The frequency for heterozygotes is: Question options: a) 0.18 b) 0.9 c) 0.1 d) 0.01 e) 0.81 - Answer 0.18 Please identify to which group the biological species concept could be applied by selecting the most-correct response. Question options: a) archaea b) whale species with vestigial hind limbs c) hinnies d) fossil birds e) bacteria - Answer whale species with vestigial hind limbs Please select the response that explains most accurately how the Hardy-Weinberg equilibrium principle may be used by bright BIOLOGY 1M03 students as a model for generating predictions. Question options: a) It specifies expected genotype frequencies in a population under ideal conditions. b) It can be applied only to loci at which reside two alleles, one dominant and one recessive. c) It can be used to specify what allele frequencies should be observed if natural selection is affecting a particular gene locus encoding a phenotype. d) It specifies what conditions need to be controlled in evolutionary studies. e) It is the starting point for all evolutionary studies. - Answer It specifies expected genotype frequencies in a population under ideal conditions. Please select the response that presents a phenomenon that a hard-core population geneticist would identify as unassociated with evolution. Question options: a) founder events b) outbreeding c) gene flow d) mutation e) assortative mating - Answer assortative mating Please select the response that presents the most-accurate statement. Question options: a) Mycobacterium tuberculosis populations in patients can become drug resistant over time. b) Evolution by natural selection is random. c) The largest, strongest, and most dominant individuals in a population produce the most offspring. d) In 1977, individual finches in the Galápagos Islands adapted to drought conditions by growing deeper beaks and passed those changes to their offspring. e) None among the other responses is correct. - Answer Mycobacterium tuberculosis populations in patients can become drug resistant over time. Please select the response that describes most correctly why the term 'genetic drift' is appropriate. Question options: a) From an evolutionary perspective, it leads nowhere. b) It is most remarkable in its effects in small populations, in which allele frequencies fluctuate stochastically. c) It ultimately is the source for genetic variability. d) It describes situations in which allele frequencies drift upwards stochastically. e) It results from populations drifting into different habitats. - Answer It is most remarkable in its effects in small populations, in which allele frequencies fluctuate stochastically. Extinct and transitional forms in the fossil record provide support for the pattern component in the theory of evolution by natural selection; please select the response that best explains why. Question options: a) They prove that evolution occurs. b) They support the hypothesis that species evolve to become more complex over time. c) They support the hypothesis that individuals change over time. d) They support the hypothesis that species have changed through time. e) They support the hypothesis that weak species are eliminated by natural selection. - Answer They support the hypothesis that species change over time. Speciation is caused by genetic isolation and genetic divergence. Please select the response that explains most accurately why genetic isolation is important. Question options: a) Isolation amplifies the effect that mutations have on populations. b) Isolation leads to inbreeding and rapid divergence. c) Allele frequencies always decrease independently in isolated populations. d) Isolation makes independent allele frequency changes between populations more likely. e) Isolation is common and can result from any mechanism that reduces gene flow between populations. - Answer Isolation makes independent allele frequency changes between populations more likely. BIOLOGY 1M03 student Eve O. Lushon observes many distinct snail populations, occupying land by the highway spanning from Hamilton to Toronto; the population in Hamilton has the lowest genetic diversity measure, whereas the population in Toronto has the greatest genetic diversity measure; populations in between have intermediate genetic diversity measures, decreasing with distance from Toronto toward Hamilton. The process underlying the observed pattern most likely involves: Question options: a) sequential founder events, with the original population residing in Toronto. b) sequential founder events, with the original population residing in Hamilton. c) a population bottleneck. d) a genetic bottleneck. e) surfing. - Answer sequential founder events, with the original population residing in Toronto Darwin described evolution with the phrase "descent with modification." Please select the response that describes most accurately from a modern perspective what the phrase entails. Question options: a) All species are identical at the genetic, developmental, and structural levels. b) Evolution takes a long time - it is a gradual process - and produces decent results. c) Evolution is a natural phenomenon that is ongoing, changing individuals even today. d) Populations living today are related (genetically) to populations that lived in the past, but they are non-identical. - Answer Populations living today are related (genetically) to populations that lived in the past, but they are non-identical. Recent work has shown that homologous genes are involved in the early development of ray-finned fish fins and lobed-fin fish limbs. Do these data support the data in the fossil record or conflict with it? Question options: a) Support— if fins and limbs are homologous, then their development should involve homologous genes. b) Conflict—ray-finned fins have bones arranged differently than they are - linearly - in limbs, so their development should involve different genes. c) Neither support nor conflict—ray-finned fins and lobed-fin limbs represent Trumpaplasy, so cannot be compared in a meaningful manner. d) Support—if fins and limbs are homoplasous, then their development should involve homoplasous genes. e) Conflict—fins and limbs have different functions, so their development should involve different genes. - Answer Support— if fins and limbs are homologous, then their development should involve homologous genes.