AP Bio Exam #1 Part B
Finches with bigger beaks are better able to crack thick-walled seeds and produce more surviving offspring.
A biologist spent many years researching the rate of evolutionary change in the finch populations of a group of islands. It was determined that the average beak size (both length and mass) of finches in a certain population increased dramatically during an intense drought between 1981 and 1987. During the drought, there was a reduction in the number of plants producing thin-walled seeds. Which of the following statements might best explain the increase in average beak size in the finch population during the drought?
Collecting fossils from rock layers deposited prior to the Permian period that contain some early vertebrate bones
A group of students summarized information on five great extinction events. The students are sampling a site in search of fossils from the Devonian period. Based on the chart, which of the following would be the most reasonable plan for the students to follow?
0.495
A particular gene has two alleles, a dominant allele A and a recessive allele a. The frequency of allele A is 0.55. If the population is in Hardy-Weinberg equilibrium with respect to the gene, then what is the expected frequency of genotype Aa?
The progeny of a cross between two different lizard species fail to develop properly.
All of the following are examples of prezygotic genetic isolating mechanisms EXCEPT:
After many generations, the offspring of the introduced guppies will mature at an older age and larger size because of selective pressure from the new predator.
Evolutionary biologists have observed variation in the average age and size of mature individuals in a population of small freshwater guppies. Guppies found in pools with pike cichlids— a predator fish that preys primarily on larger guppies—reproduce at a young age and are small at maturity. Guppies found in pools with killifish —a different predator fish that preys primarily on smaller guppies—reproduce at an older age and are larger at maturity. Which of the following predicts the most likely outcome of moving a population of guppies from a pool with pike cichlids to a pool with killifish?
Gene flow is unlikely to occur between the two populations because they are geographically isolated.
Figure 1. The distribution of individuals from two populations of the same species at different elevations Researchers investigating two populations of the same species recorded the elevation at which individuals from each population were found (Figure 1). Which of the following claims is best supported by the data in Figure 1 ?
The two species have a different number of chromosomes, resulting in a postzygotic barrier.
Goats and sheep belong to the same family but different genera. While they often live together in the same pastures, the hybrid offspring that are occasionally produced between the two species rarely survive. When such a hybrid does survive, it is usually sterile. Which of the following best explains the mechanism that maintains reproductive isolation between goats and sheep?
leave the greatest number of reproducing descendants
In Darwinian terms, the fittest individuals of a species are those that
Humans are more closely related to a jawless fish like a lamprey than to a mollusk like a sea slug.
In the chart above, the numbers represent the number of amino acid differences between the beta chain of humans and the hemoglobins of the other species. Which of the following statements is supported by the data?
Insects that are naturally resistant to the pesticide will survive and reproduce more than the insects that are sensitive to the pesticide.
Pesticides are chemicals that are often sprayed on crops to kill plant-eating insects, preventing damage to the crops. While pesticides are effective initially, many researchers claim that any single pesticide will see reduced effectiveness in as little as ten to fifteen years. Which of the following best supports the claim by scientists that the pesticides will eventually lose their effectiveness?
1,133
The TAS2R38 gene encodes a receptor protein that influences the ability to taste bitterness. The gene has two alleles: a dominant, wild-type allele that enables an individual (taster) to taste bitterness and a recessive, mutant allele that interferes with the ability of an individual (nontaster) to taste bitterness. Three single nucleotide mutations in the coding region of the TAS2R38 gene are associated with the nontaster allele. The nucleotides present at the three positions are shown in the table below. A cladogram representing the evolutionary relatedness of selected primates is shown below. In a sample of 2,400 people, 1,482 were found to have the dominant (taster) phenotype. Assuming that the population is in Hardy-Weinberg equilibrium, approximately how many individuals in the sample are expected to be heterozygous for TAS2R38?
II, I, III, IV
The gene encoding the catalytic subunit of cytochrome c oxidase (MT-CO1) is found in the mitochondria of all animals. The gene evolves rapidly and is often used to determine evolutionary relationships among species. Table 1 shows DNA sequence differences among four animal species (I, II, III, and IV). Which of the following cladograms best represents the evolutionary relationships among the four species?
65 mya
Which mass extinction was responsible for the demise of the dinosaurs?
House sparrows that lay smaller-than-average clutches of eggs produce fewer viable offspring, while larger-than-average clutches of eggs result in malnourished chicks that have a higher mortality rate.
Which of the following describes a scenario that would result in the phenotypic change shown in the graph? Responses
Mass extinctions reduce the diversity of organisms initially.
Which of the following is a true statement about all mass extinctions?
It is the only time the supercontinent has formed.
Which of the following is not true about the Mass Extinction 250 million years ago?
Iridium, which is common in meteorites but rare on Earth, is found in sedimentary rock that contains the last appearance of many species in the fossil record.
Which of the following observations best supports the hypothesis that a large object collided with Earth in a period of time associated with a mass extinction?
They produce viable but sterile offspring.
Which of the following observations would provide the strongest evidence that two plants belong to different biological species?
The skulls of birds and crocodilians have an opening that is absent in the skulls of other reptiles.
Which of the following pieces of evidence best supports the hypothesis that birds and crocodilians (crocodiles and alligators) are more closely related to each other than they are to other organisms? Responses
If the three animals denoted by A, B, and C are alligator, lizard, and earthworm, the earthworm would likely be species A.
Which of the following statements is TRUE regarding the cladograms above, all of which show the relatedness between species (A-I)?
Gradualism
Which rate of speciation is depicted above?
Land-dwelling and tetrapods
Which shared derived characters are seen in both reptiles and amphibians?
Cartilaginous Fishes
Which species would be considered the outgroup?
Whales & Other Mammals
Which two organisms have the most recent common ancestor?
Individuals with different adaptations in shell shape and leg length best exploited the food resources and left more surviving offspring on each island.
While there is only one species of Galápagos Island tortoise, there are several subspecies. Larger islands with more wet highlands have lush vegetation near the ground. Tortoises there tend to have high-domed shells and shorter necks, which restrict upward head movement. They also have shorter limbs. They are the heaviest and largest of the subspecies. Smaller, drier islands are inhabited by tortoises with longer necks and limbs and with shells that are elevated above the neck, which allow them to browse taller vegetation. Based on the information given, which of the following is a plausible explanation for the ancestry of the tortoise subspecies?
