AP Bio Homework Part 2
A scientist is attempting to provide support for the hypothesis that RNARNA was the first genetic material. Which of the following would be a workable alternate hypothesis? A RNARNA, like DNADNA, is a carrier of genetic information and contains the nitrogen bases adenine, guanine, and cytosine. B RNARNA can be observed to self-replicate without the assistance of proteins, while DNADNA always requires protein-based enzymes to replicate. C RNARNA exists in both single-stranded and double-stranded configurations; however, it is less stable compared with DNADNA. D Transfer RNARNA and ribosomal RNARNA are products of transcription, but they are not translated as is mRNAmRNA.
B
Female European corn borer moths (Ostrinia nubilalis) produce the sex pheromone 11−11−tetradecenyl acetate (11−TDA11−TDA), which attracts males of their species. 11−TDA11−TDA can be produced in two forms, EE and ZZ, each with a different three-dimensional shape. Researchers have discovered two different strains of the European corn borer moth living in the same area. Females of the EE strain produce primarily the EE form of 11−TDA11−TDA and females of the ZZ strain produce primarily the ZZ form of 11−TDA11−TDA. Males of both strains are more attracted to the form of 11−TDA11−TDA produced by the females of the same strain. Which of the following best predicts a long-term effect of the differences between the EE and ZZ strains? A The difference between the forms of the sex pheromone 11−TDA11−TDA produced by EE and ZZ strains will act as a prezygotic reproductive barrier leading to sympatric speciation. B The difference between the forms of the sex pheromone 11−TDA11−TDA produced by EE and ZZ strains will act as a postzygotic reproductive barrier, leading to allopatric speciation. C Since the EE and ZZ strains are both part of the same species, they will produce fertile offspring, leading to a single strain that produces both forms of 11−TDA11−TDA. D Since the EE and ZZ strains are found in the same geographic area, they will hybridize, leading to a single strain that produces the dominant form of 11−TDA11−TDA.
A
Scientists want to determine whether the rapid economic growth in China between 1950 and 2000 caused a mass extinction of animal species during that time period. A mass extinction event is considered to occur when the rate of species extinction far exceeds the background extinction rate. The scientists collected data on the number of extinctions of selected vertebrate species in China between 1950 and 2000, as shown in Table 1. Extinction rates were ascertained by measuring the average percent of species lost (PSL)(PSL). Which of the following is the null hypothesis most relevant for evaluating the data in Table 1 ? A There is no significant difference between the extinction rate of animals between 1950 and 2000 in China and the background extinction rate. B There is no significant difference between the extinction rates of mammals, birds, amphibians, and reptiles in China. C There is a significant difference between the extinction rate for mammals in China and the background extinction rate for mammals. D Because of climate change, habitat loss, pollution, and excessive exploitation of resources, China experienced a mass extinction event between 1950 and 2000.
A
Some scientists claim that amphibians are currently experiencing a period of mass extinction. Which of the following should be included in an alternative hypothesis that would best support this claim? A The current extinction rate of amphibians compared with the background rate of extinction as determined by the fossil record B The extinction rate of amphibians in the 21st21st century compared with the extinction rate of amphibians during the 20th20th century C The number of species of amphibians currently alive compared with the number of amphibian species known to be extinct D The number of new amphibian species being discovered per year compared with the number of amphibian species becoming extinct during the same time period
A
Dr. Robert Hazen has worked to develop a hypothesis that explains the origin of life on Earth. His work has focused on hydrothermal vents, which are cracks in the ocean floor. Water heated by molten rock beneath the crust escapes from these vents at very high temperatures, producing hot, high‑pressure environments at the vents on the ocean floor. In order to provide evidence that these vents may be areas where life originated, which of the following states a null hypothesis Hazen might have used to begin his research? A Organic molecules were transported to the hydrothermal vents via a meteorite, thereby seeding them with precursors for more complex molecules. B The temperatures and pressures found in hydrothermal vents resemble conditions described in currently accepted origins of life hypotheses. C Organic waste sinking to the ocean floor would have used the unique hot water environment as an energy source to begin manufacturing food. D Chemosynthetic organisms can best develop in the hydrothermal environment, manufacturing nutrients for other living things to feed on.
B
Finch beak depth was measured before and after a severe drought in 1977. The averaged results are shown in Figure 1. After the drought, there were fewer seeds available for the finches to eat and the seeds that did remain were larger and harder to crack open. Researchers claim that when large, hard seeds are the predominate food source, the average beak depth of these finches tends to increase in subsequent generations. Figure 1. Finch beak depth before and after the 1977 drought Using the evidence provided, which of the following best justifies the researchers' claim? A Finch beak depth increased after the drought because the overall numbers of finches decreased, reducing competition for resources. B Finch beak depth increased as a consequence of selective pressure after the drought because the remaining seeds were larger and harder. C Finch beak depth increased after the drought due to intraspecific competition since finches with deeper beaks attract more mates. D Finch beak depth increased after the drought due to increased predation since finches with deeper beaks can fight off predators more effectively.
B
Paleoclimatic analysis has generated a claim that there is a possible correlation between an extinction event around 29 million years ago that allowed grasslands to become abundant and the adaptive radiation of several groups of butterflies. Which of the following proposes the best alternative hypothesis for the claim? A Climate analysis conducted by sampling pollen preserved in amber shows an increase in grass pollen 29 million years ago, but there is no significant difference between speciation rate, as well as species richness with regard to butterflies, before and after 29 million years ago. B Climate analysis conducted by sampling pollen preserved in amber shows an increase in grass pollen 29 million years ago, which indicates there was an increase in grasslands that correlates to an increase in butterfly speciation during the same time period. C There is a correlation between the rapid and wide-ranging decrease in species richness of insects in general 29 million years ago and the increase in species richness and diversity among the butterfly population during the same time period. D Evidence of rapid speciation among butterfly species 29 million years ago is evenly distributed among all environments of that period.
B
Commercial bananas are grown as a monoculture, with all banana plants cloned from one original banana plant. The commercial strains of bananas are seedless, so each new banana plant has to be manually planted from a cutting of an existing banana root. In the 1950s, the Gros Michel banana strain, the dominant export banana at that time, was destroyed by the fungus Fusarium oxysporum. A new Fusarium resistant variety, the Cavendish banana, was developed and is currently the banana strain grown for export. Recently, a Fusarium strain that successfully attacks the Cavendish strain has been documented. Which of the following best provides reasoning supporting a method that would help protect commercial banana crops from infection by pathogenic organisms such as Fusarium fungi? A The commercial banana strains should be exposed to XX-rays to encourage random mutations that will then be passed to offspring, producing resistance to pathogenic organisms. B The Cavendish banana plants should be exposed to pathogenic organisms under controlled conditions, so the plants can be encouraged to mutate and develop resistance to the pathogens. C The commercial banana strains should not be grown in monocultures, since many pathogenic organisms are able to evolve rapidly in response to a single selective pressure. D Growing the Cavendish strain under different conditions will allow natural selection to produce the variation needed to resist infection by pathogenic organisms.
C
Many scientists claim that the synthesis of the first organic molecules from inorganic precursors was possible because of the highly reducing atmosphere found on primitive Earth. Which of the following is an appropriate null hypothesis that could be used when investigating the claim? A The level of atmospheric oxygen on modern Earth is significantly higher than on primitive Earth. B Organic molecules were transported to primitive Earth by a meteorite or other celestial event. C The synthesis of organic molecules from inorganic molecules is possible under current atmospheric oxygen levels as well as those found on primitive Earth. D The absence of a significant quantity of atmospheric oxygen is required for the synthesis of organic molecules from inorganic precursors.
C
One of the oldest known mammalian fossils belongs to a small furry species, Hadrocodium wui, that lived 195 million years ago. For the following 100 million years, only a small number of groups of mammalian fossils are found in the fossil record. By 65 million years ago, the nonavian dinosaurs were extinct. By 55 million years ago, there were 130 mammal genera, including 4,000 different species that occupied a wide variety of habitats. Which of the following best describes the cause of the rapid increase in the number of mammalian species between 65 and 55 million years ago? A It took over 100 million years for enough random mutations to occur in the genomes of early mammals to provide the variation needed for the observed speciation. B It took over 100 million years for the early mammals to disperse over a wide enough geographic area to allow allopatric speciation to occur. C After the dinosaur extinction, many ecological niches became available, leading to the adaptive radiation of mammals. D After the dinosaur extinction, mammal population sizes increased, allowing species to become more easily detectable in the fossil record.
C
Rock pocket mice live in the deserts of the American southwest. Ancestral pocket mice all had light-colored coats that blended in with the region's rocks and sandy soil, keeping the mice hidden from predatory owls. About 1.7 million years ago, a series of volcanic eruptions spewed out wide trails of black lava into the middle of rock pocket mouse territory. Currently there are two color morphs of rock pocket mice: light-colored mice that are typically found in habitats with sandy soil, and dark-colored mice that are typically found in habitats with dark-colored lava rocks. Which of the following best justifies the claim that alleles that may be adaptive in one type of environment can be deleterious in another because of different selective pressures? A Light- and dark-colored mice survive in many environments because they are able to avoid predation by moving into tunnels. B Light-colored mice are more likely to survive than dark-colored mice in habitats with lava rocks and sandy soil. C Light-colored mice are significantly more susceptible to predation by owls in habitats with lava rocks than in habitats with sandy soil. D Dark-colored mice are more likely to survive than light-colored mice in habitats with lava rocks and sandy soil.
C
A small number of lizards from a mainland population have been deposited on four isolated islands because of the effects of a rare strong storm. Which of the following best predicts the outcome of these lizards reproducing for many generations on the islands? A Courtship rituals specific to each island lizard species prevent the lizards from interbreeding. B Speciation results from bottleneck events that happened before the ancestral species reached the islands. C The different species that currently exist are the result of hybridization between lizards from different islands. D The isolation prevents gene flow; thus, the lizards on different islands experience prezygotic isolation.
D
Which of the following best explains how the ecological conditions are likely to be different in the two models? A In model A the ecological conditions remain unchanged for long periods of time and then change drastically; in model B the ecological conditions change drastically from generation to generation. B In model A the ecological conditions remain unchanged; in model B the ecological conditions change gradually over long periods of time. C In model A the ecological conditions are changing drastically from generation to generation; in model B the ecological conditions remain unchanged. D In model A the ecological conditions change gradually over a long period of time; in model B the ecological conditions remain unchanged for long periods of time and then change drastically.
D
