Primavera Biology B Unit 4: Evolution Questions and Answers Graded A

Primavera Biology B Unit 4: Evolution Questions and Answers Graded A CHECKPOINT 17 What gas present in today's atmosphere was largely absent from early Earth's atmosphere? oxygen What are some possible sources for early organic molecules? Select all that apply. existing inorganic molecules forming into more complex organic ones by using energy from lightning simple inorganic compounds arriving on Earth through meteorites or other objects Which option correctly replaces X and Y? The Miller-Urey experiment resulted in the formation of several X molecules that are the basis for Y. X: amino acid Y: proteins Study the experiment illustrated by the following image: What aspect of early Earth was the spark meant to recreate? lightning What were the products of experiments that were similar to the one Miller and Urey conducted? organic compounds Which two organelles are thought to have arisen from prokaryotes that became engulfed by other cells according to the theory of endosymbiosis? mitochondria and chloroplasts What does the RNA world hypothesis state about ribozymes? Ribozymes were once more common than they are now. They eventually got replaced by proteins. What functions are central to RNA in the RNA world hypothesis? Select all that apply. RNA can serve as a genetic code. RNA strands can act as enzymes. What are RNA molecules that can act as enzymes? ribozymes CHECKPOINT 18 Which of the following are true of natural selection? Select all that apply. It reduces the frequency of unfavorable traits in a population. It increases the overall fitness of the species. A population contains a lot of diversity in genetic traits. What condition does this describe? variation Overproduction results in more individuals in a population than the resources can support. What does this cause? competition A whale's fin is homologous to which of the following? a human's arm Which of the following evidence for evolution can be obtained from fossils? transitional stages Which of the following would be true of plants found growing in deserts on different continents? Select all that apply. They share special adaptations that are analogous. They show more similarities to other plants on the same continent that they do to each other. Which of the following statements about the beaks of the Galápagos finches is correct? Their beaks were adapted to the finches' particular environment. What is a model that uses DNA comparisons to see how long two different organisms have been evolving independently from each other? molecular clock hypothesis The same DNA strand is analyzed in four species of fish. Two species have more identical nucleotides than the others. What does this mean? They are more closely related. Study the image. Which two species are most closely related? pigeon and spotted dove In a phylogenetic tree, what does a node represent? a shared common ancestor CHECKPOINT 19 Which of the following statements about the Hardy-Weinberg principle are true? Select all that apply. It assumes certain forces are not acting on a population. It is used to model genetic equilibrium. The Hardy-Weinberg principle assumes that certain forces are not acting on a population. If they are acting, they could cause evolutionary change. What are some of these forces? Select all that apply. mutations occurring natural selection occurring Read the statement. A new allele added to the gene pool provides an advantage. The individual with the allele breeds and passes on the trait to their offspring. This describes the evolutionary effects of what process? mutation Read the statement. A natural disaster reduces the size of a population. The allele frequencies in the population may change after the disaster. What type of population does this have the strongest evolutionary effect on? A small-sized population. New individuals are introduced to a population, bringing in new alleles and combinations of genetic traits. What evolutionary process does this describe? gene flow Read the statement. A population has a variety of genetic traits and produces more individuals than resources can support. Individuals within the population compete against each other for resources. Survivors reproduce and pass on beneficial genetic traits to their offspring. What evolutionary process does this describe? natural selection A single phenotype is favored because individuals with its allele have a higher fitness. What form of natural selection does this describe? directional selection What is disruptive selection? a form of natural selection in which individuals with extreme representations of a trait are favored over the average A single average phenotype is favored. What form of natural selection does this describe? stabilizing selection Study the histogram. What form of natural selection does the histogram show? disruptive selection CHECKPOINT 20 What is allopatric speciation? different populations of the same species physically separated from each other forming new species What is sympatric speciation? different populations of the same species in the same geographic area forming new species What is adaptive radiation? the evolution of many species from a single ancestor in a short amount of time What is true about polyploidy and speciation? Select all that apply. Asexual reproduction helps polyploidy lead to speciation. It can happen fast. Study the diagrams below and then answer the following three questions. Which type of evolution is illustrated by diagram A? parallel evolution Which statement correctly defines coevolution? two entirely different species affecting each other's evolution, as in predator-prey relationships A dog is trained to salivate at the sound of a bell. What type of behavior is this, and is it innate or learned? conditioning; learned behavior Which of the following are behaviors that are used to defend against predators? Select all that apply. forming a herd playing dead forming a school What is a result of group behavior that enhances survival? having an easier time finding mates