AP Biology Unit 8

A fish population of 250 in a pond has a maximum annual rate of increase of 0.8. If the carrying capacity of the pond is 1,500 for this species, what is the expected population size after one year?

417

A photosynthetic organism would be represented by which species?

A

Hydrangea macrophylla is a species of plant with blue or pink flowers. Flower color in Hydrangea macrophylla plants is thought to be determined primarily by soil conditions rather than by inherited differences. Which of the following will provide the most direct evidence that flower color in Hydrangea macrophylla is due primarily to soil conditions?

Growing cuttings from the same Hydrangea macrophylla plant under controlled conditions that vary only with regard to soil pH

A group of researchers suggest that the concentration of available phosphate in this particular section of the British river does not have a significant impact on which plant species grow. Alternatively, another group of researchers hypothesize that levels of available phosphate do affect which plant species grow at this location. Which of the following observations would best support this alternative hypothesis?

Increased fertilizer use near this section of the river has led to increased runoff of phosphates into the river.

Which of the following changes to the environment will most likely lead to more energy entering the meadow community represented above?

Increasing the light available to the plants

Which of the stream types had a statistically lower macroscopic invertebrate species diversity than the seasonal streams?

Intermittent streams only

Which of the following best supports the alternate hypothesis that zebra mussels display characteristics of an invasive species?

Lacking natural predators and able to outcompete native species of mussels and other freshwater species for food, zebra mussels have experienced exponential population growth and rapid expansion into new habitats.

As depicted in the diagram, honeybees communicate the location of flower patches to members of their hives with waggle dances that give information about the direction and distance to the flowers. Which of the following statements about how honeybees communicate the position of flower patches is most consistent with the model?

The farther the target flowers from the hive, the longer the waggle phase.

Mosquitoes are frequently a target of insect control strategies because of their ability to spread disease. One strategy is to introduce guppies, a type of freshwater fish, into areas where mosquitoes are a problem. Guppies can consume large numbers of mosquito larvae, which cuts down on the number of mosquitoes living to adulthood. Researchers assessing the effectiveness of the guppy solution are concerned that the introduction of guppies might cause more problems than it is fixing. Guppies are hardy, tolerant of a wide range of environmental conditions, and fast-reproducing. Which of the following predicts the most likely ecological problem that would occur if guppies are introduced into new areas to control the mosquito population?

The guppies might have no natural predators, which will result in a dramatic increase in the guppy population and an increase in competition for other native species.

Decades of seal hunting eliminated many fur seal breeding colonies. Since that time, fur seals have recolonized several islands in the Pacific Ocean. Scientists studying the populations of fur seals on three recently colonized islands observed different population growth rates among the three populations. Which of the following best explains the different population growth rates on the recently colonized islands?

The islands differed in the amount of available space for breeding, resulting in higher growth rates on islands with more available breeding space.

Researchers were studying species diversity in a savanna rangeland community in southwest Queensland, Australia. Researchers counted the numbers of plants species in four different categories at two nearby sites within the savanna rangeland; one lightly grazed by herbivores and one heavily grazed by herbivores (Figure 1). Which of the following best predicts the results of a drought in the savanna research area with regards to community resilience to this environmental change?

The lightly grazed area is likely to recover more quickly from the drought due to greater biodiversity.

The researcher claims that there is no selective advantage to fur color, so light and dark fur color phenotypes are present in similar frequencies in the fourth generation of this mouse population. Based on the data in Figure 1, which of the following best evaluates this null hypothesis?

The null hypothesis is rejected, because the change to a darker background color led to an increase in the dark-colored fur phenotype.

The Irish Lumper variety of potato was introduced into Ireland in the early 1800s. The Lumper soon became the only variety of potato grown in much of Ireland. The potato blight destroyed most of the Lumper crop between 1845 and 1852 resulting in the death of about 1 million Irish from starvation. A researcher suggests that the Irish monoculture (growing a single crop) of the Lumper potato did not significantly change the overall resistance of the potato crop in Ireland to diseases. Which of the following observations best refutes this null hypothesis?

The number of fatalities from the Irish potato famine was greater than the rest of the European countries combined.

Based on the information in Figure 1, which of the following best predicts a short-term effect of removing secondary consumer X from the community?

The one with a significantly larger shaded white circle in the primary consumer level. Answer choice A

Which of the following correctly identifies the dependent and independent variables in this experiment?

The percentage of plants showing phototropism is the dependent variable, and the color of the light is the independent variable.

Figure 1 represents the feeding relationships between selected organisms in the Chesapeake Bay. Decades of overharvesting have reduced the populations of both blue crabs and rockfish. However, recent efforts have increased the number of rockfish in the bay. Based on Figure 1, what is the most likely result of the increase in rockfish?

The population of blue crabs will decrease because predation by rockfish will increase.

The population of Japanese sika deer in central Japan was determined each year from 2005 to 2014. The sika deer population underwent logistic growth starting at 26,000 deer in 2005 and stabilized at 58,000 deer between 2012 and 2014. Based on these data, the rmax for this population was determined to be 0.57. Central Japan contains a variety of habitats, including forests and grasslands. Sika deer benefit from the resources in grasslands more than forests; if deforestation occurred, producing more grasslands in the region, the carrying capacity for sika deer population would increase. What would the population size of sika deer be one year after the carrying capacity increased to 70,000 as a result of deforestation? Assume rmax does not change.

The population would grow to 63,667 deer in a year, and the growth rate would decrease the following year.

Meerkats live together in groups to help raise and protect their offspring. Meerkat pups are most vulnerable when they are away from their burrow foraging for food. Adult meerkats exhibit sentinel behavior, standing upright and making alarm calls to warn other members in the group that predators are nearby. In a study of meerkat behaviors, scientists observed meerkat foraging groups and recorded the presence or absence of pups along with the frequency of adult sentinel behavior. The scientists determined that sentinel behavior increased when pups were present in the foraging group. Which of the following correctly identifies the dependent and independent variables in the described study?

The presence of pups is the independent variable, and the frequency of sentinel behavior is the dependent variable.

Wolves, once native to Yellowstone National Park, were hunted to the point of complete extinction in the park. As a result, the elk population in the park flourished, putting extra demands on the carrying capacity of the park. Many other species, such as certain trees and beavers, were negatively affected by the increase in elk. Years later, wolves were reintroduced into the park. While the elk population decreased after the wolves returned, the beaver and songbird populations began to increase as did the populations of various plant species. Which of the following best explains how wolves are a keystone species in this ecosystem?

Wolves help balance the population sizes of other species, allowing more species to thrive in the wolves' presence than in their absence.

In a study of energy flow, the following data were collected: Each human requires 55 grams of protein per day. An acre of soybeans produces 200,000 grams of protein per year. A cow grazing on one acre of land produces 19,000 grams of protein per year. Based on these data, an acre of land would support: 10 humans per year on a diet of soy, or 0.9 human per year on a diet of beef. Which of the following statements best explains these relationships in terms of energy transfer?

Only 10% of the energy on each level of the trophic pyramid is available for use by the next level. The rest is lost as heat or used for growth and repair.

In 1991, researchers at Adak Island observed the first attack by a killer whale on a sea otter in historical times. The researchers hypothesized that the population sizes of the larger marine mammals that the killer whales normally prey on declined, so the killer whales were starting to prey on different prey, including the smaller sea otters. Which of the following best predicts the effects of an increase in killer whale predation on sea otters on the Adak Island ecosystem?

The sea urchin population will increase and the kelp population will decrease, leading to reduced total biomass and diversity in the Adak Island ecosystem.

A population of 250 birds inhabit the canopy of a tropical rain forest that has a carrying capacity of 400 birds. What is the maximum population growth rate (rmax) if the population grows to 283 in one year?

0.35

Germination would be expected to occur first in which beaker?

1

Based on the data in the figure, a student claimed that since 2007, the carrying capacity of wolves in Yellowstone National Park has been 100 wolves, and the maximum annual per capita growth rate of gray wolves is 0.6 wolves per wolf per year. Which of the following is closest to the calculated wolf population size in 2017 based on the student's claim?

103

Based on information in Figure 1, which of the following is closest to the annual growth rate of the wolf population in Yellowstone National Park from 1996 to 2004 ?

17 wolves per year

Which of the following best estimates the population size of the sea lions in 2000 based on the data shown in Figure 1?

175,000

The difference in carrying capacity between the two species when cultured separately is closest to which of the following values?

350 individuals per 5.0 mL

Based on the data, which of the following is the best approximation of the rate of growth per week in section II from day 14 to day 21 ?

4.5 g/week

Based on the data in Figure 1, which of the following statements is most accurate about the species diversity of the four different environments that the students analyzed?

Based on the data, there is no statistical difference between the species diversity of plants in the light, moist environment and in the dark, moist environment.

In some species of bats, adult females regurgitate (bring up food from the stomach) to feed their young. In addition, adult bats regurgitate to feed other adults that have not recently eaten. The adults receiving the food may be unrelated bats who have previously participated in food sharing and are members of the same social group. Scientists claim that sharing among unrelated adult bats increases the fitness of the species. Which of the following best supports the scientists' claim?

Bats that do not find food over a 24-hour period may die, preventing their alleles from being passed on within the social group.

Scientists have found that the existing populations of a certain species of amphibian are small in number, lacking in genetic diversity, and separated from each other by wide areas of dry land. Which of the following human actions is most likely to improve the long-term survival of the amphibians?

Building ponds in the areas of dry land to promote interbreeding between the separated populations

Producers within very deep regions of the ocean most likely introduce energy into ecosystems through which of the following processes?

Capturing electrons from inorganic molecules

Which of the following describes the mechanism by which a plant stem grows toward light?

Cells on the dark side of the stem elongate more than those on the lighted side.

Which of the following investigations would enable researchers to test the claim that an increased concentration of algae has a negative effect on the number of aquatic invertebrates in the ecosystem?

Counting the number of aquatic invertebrates at different concentrations of chlorophyll a in the water

Which of the following best describes the change in coyote behavior in the presence of wolves?

Decreases, no effect, no effect, increases, increases

Which of the following statements is consistent with the data shown in the figures?

Different patterns of energy availability in ecosystems will affect species richness.

Which of the following statements correctly describes a typical trend during the initial stages of succession in a terrestrial ecosystem?

Diversity of plant species increases.

Which point on the curve in the diagram above best represents the carrying capacity of the environment for the population shown?

E

Testosterone oxido-reductase is a liver enzyme that regulates testosterone levels in alligators. One study compared testosterone oxido-reductase activity between male and female alligators from Lake Woodruff, a relatively pristine environment, and from Lake Apopka, an area that has suffered severe contamination. The graph above depicts the findings of that study. The data in the graph best support which of the following claims?

Environmental contamination reduces total testosterone oxido-reductase activity in females.

The food web represented above does not include bacteria and fungi. Which of the following best describes a consequence of having no bacteria and fungi in the food web?

Grasses will have no direct access to chemical components recycled from dead organisms.

Identify the experimental design that would determine which AIP mimic would most effectively inhibit the production of hemolysin toxin.

Grow S. aureus in separate culture media containing one AIP mimic each and measure the production of hemolysin toxin. The most effective AIP mimic will be in the culture producing the lowest amount of hemolysin.

To investigate whether an organism in the study is capable of both photosynthesis and respiration, a comparison of which treatment groups is most appropriate?

I and II

In an investigation of interspecies competition, researchers grew the unicellular protozoan Paramecium aurelia in a 5 mL culture and Paramecium caudatum in a separate 5 mL culture. P. aurelia and P. caudatum were grown together in a third 5 mL culture. Each day a small sample of each culture was removed so the total number of individuals could be estimated, and the remainder of the population was transferred to fresh growth medium. The experimental results are represented in the graphs below. Which of the following conclusions is best supported by the results of the experiment?

Neither population grows as large when cultured together as each does when cultured separately.

Which of the following communities is likely to be most stable?

One with high species diversity

In the early 1970s, researchers hypothesized that carbon was the limiting nutrient in many aquatic ecosystems. To test this hypothesis, the researchers divided a small lake in two roughly equal halves with an impermeable curtain that was fastened and sealed to the bedrock of the lake. Beginning in 1971 the researchers treated one side of the lake with sucrose and the other side with both sucrose and phosphate. From 1971 to 1983 the researchers monitored the phytoplankton biomass in both parts of the lake. The results are shown in Figure 1. Which of the following claims is best supported by the data?

Phosphate was a limiting factor for phytoplankton in the lake.

Which of the following additions to the experimental design will best help test whether the observed habitat preferences were the result of competition between species?

Placing two individuals from the same population together inside the enclosure

Which of the following observations would best support this alternative hypothesis?

Previous dips in plankton abundance coincided with other El Nino events.

Which of the following most accurately explains an impact of Burmese pythons on the Everglades community in southern Florida using the data provided?

Python predation has caused a trophic cascade that changed the mosquitoes' niche.

Which of the following is an accurate interpretation of the data in Figure 1?

R. richardsoni is found significantly more frequently on Species 3 and Species 4 compared to Species 1 and Species 2.

Which of the following statements is most consistent with the data in Figure 1 ?

Snakes display behaviors that allow them to absorb or radiate heat as required.

Based on the data in the table, which of the following best predicts the results of a study in which natural populations of T. atratus and T. sirtalis are observed together in an environment that includes a freshwater pond?

T. sirtalis will be observed near the water whether or not T. atratus is present.

Scientists hypothesize that the invasive Burmese pythons are responsible for recent increases in human Everglades virus infections. Evaluate this alternate hypothesis using the data provided.

The alternate hypothesis is supported because the invasive Burmese pythons caused mosquitoes to switch to feeding on cotton rats. This means that mosquitoes are more likely to carry the Everglades virus when they bite humans.

Which of the following describes how the vent bacteria harvest energy to produce organic compounds for use by the vent community?

The bacteria function as chemoautotrophs, extracting energy from hydrogen-rich inorganic molecules.

Which of the following correctly identifies the dependent variable and the independent variable for the experiment?

The dependent variable is the percent change in the amount of nicotine, and the independent variable is the time interval the plants were exposed to the hornworms.

A massive increase in the growth of a specific species of algae resulted in record-breaking levels of a potentially dangerous toxin being released into the water. A researcher hypothesizes that the unusual growth of this algal species was caused by an increase in water temperature. The researcher designs an experiment to test the hypothesis. Which of the following is the dependent variable in the researcher's experiment?

The growth of the algae

Which of the following correctly identifies the dependent variable and the independent variable for the experiment?

The independent variable is the type of alarm, and the dependent variable is the percent of squirrels responding.

What do the data in Figure 1 suggest about a null hypothesis that the East China Sea ecosystem is unaffected by climactic events?

The null hypothesis is rejected since there are statistical effects of EAWM and PDO on surface sea temperature and copepod abundance.

Bison in Yellowstone National Park have a food-limited carrying capacity that determines how their population grows. If the population grows too large, some bison will either starve or migrate to search for more food. The park is able to support a maximum population of 4,500 bison. Park conservation officials must watch the population and prevent the bison from overpopulating, since they would migrate to nearby farms, causing agricultural damage and creating hazards to drivers. The bison begin to migrate when the population reaches 4,000 because of competition for food. If the current population size of bison is 3,652 and the maximum growth rate of the population is 0.28, calculate the population size after one year and determine whether the park will need to take measures to control the population.

The population will be 3,845 after a year. The bison will not pose a problem until the following year, and no conservation action will need to take place.

Scientists studying a wild population of mantled howler monkeys found the average birth rate to be 0.22 and the average death rate to be 0.12. At the start of the study, the population consisted of 13 monkeys. Assuming no immigration or emigration, which of the following best describes the change in population size that will occur over the next year?

The population will increase because more monkeys are being born each year than are dying.

Identify the independent variable for the experimental results shown in Figure 2.

The presence of wolves

Some researchers link changes in the distribution of these species to warming of the oceans due to climate change. Which of the following pieces of data best supports this alternative hypothesis?

The prey of these species require colder waters to survive, and owing to warming in the oceans, they are moving farther north, to higher latitudes, where the water is colder.

Zebra mussels are an invasive species that has become widely established throughout the United States. Figure 1 shows the percent change in the population sizes of selected groups of organisms in the Hudson River since the introduction of zebra mussels. In this study chlorophyll-containing bacteria are considered phytoplankton and all other bacteria are considered bacterioplankton. Which of the following hypotheses about the effect of zebra mussels on the Hudson River community is best supported by the data in Figure 1 ?

The reduction in primary productivity has resulted in an unstable community that will eventually collapse.

Of the following, which explains why the zooplankton also dipped during the same year and then seemed to cycle over the next three years?

The reduction in the phytoplankton population meant that the zooplankton's energy source was drastically reduced, leading to the decrease in the zooplankton population size. After the dip, the phytoplankton provided a steady energy source, and the zooplankton population fluctuated around its carrying capacity.

Which of the following is the most likely cause of the change in mean aspen height from 1998 to 2010 ?

The reintroduction of wolves led to a decrease in the population of elk, allowing aspen trees to grow taller.

Based on Figure 1, which of the following is the most likely short-term effect of a decrease in the killer whale population?

The sea otter and kelp populations will increase, while the sea urchin population will decrease.

Beaked whales feed at various depths, but they defecate at the ocean's surface. Nitrogen-rich whale feces deposited in surface waters supply nutrients for algae that are eaten by surface dwelling fish. Which of the following best predicts what would happen if the whale population decreased?

The surface fish populations would decline due to reduced populations of algae.

Yellow-billed cuckoos typically hatch in midJuly. Emerging cicadas are a primary food source for nesting cuckoos. Which of the following best predicts the effect of wildfires on yellow-billed cuckoo populations?

The yellow-billed cuckoo population will decline because the cicadas will emerge before the hatching season begins.

A scientist interested in investigating how human population trends might affect local animal species' richness stipulates a null hypothesis that animal biodiversity in rural areas will be unaffected in the future by the human population trends shown in Figure 1. Which of the following would best refute this null hypothesis?

Urbanization causes habitat fragmentation.

The marine iguana, Amblyrhynchus cristatus, is endemic to the Galápagos Islands and is especially vulnerable to El Niño events. These iguanas feed on red and green algae. During an El Niño climate event, surface waters and their currents in the central and eastern Pacific Ocean become significantly warmer than usual. Also during El Niño years, land masses experience increased rainfall. A researcher suggests that El Niño conditions cause a significant decrease in the size of the Galápagos marine iguana population. Which of the following would best support this alternative hypothesis?

Warm surface water contains fewer nutrients needed by red and green algae than cooler surface waters does.

Which of the following populations have significantly decreased in size between 1996 and 2011?

White-tailed deer and raccoons only

In the year 2000, specimens of Caulerpa taxifolia,a green alga used in tropical aquariums, were found off the coast of California. Native to the Indian Ocean, C. taxifolia is known for aggressive growth and an ability to compete with sea grasses.It is currently on an international list of invasive species. Which of the following best predicts the consequences of the introduction of C. taxifolia to the California coast?

Without natural herbivores or competitors,C. taxifolia will grow rapidly and crowd out native species of producers.

Which of the following best explains the data in Table 1 ?

Yeast respond to nutritional stress with sexual reproduction, producing new genetic combinations, or dormancy.

Researchers were studying the effects of microbes on the growth of the yellow bedstraw plant, Galium verum. They grew yellow bedstraw plants under four treatments: in the presence of soil bacteria only, arbuscular mycorrhizal (AM) fungi only, both bacteria and AM fungi, or neither. After 6 months, they measured the biomass of the plants (Figure 1). Which of the following best describes a statistical relationship indicated in Figure 1 ?

Yellow bedstraw plants grow significantly more in the presence of both soil bacteria and AM fungi (treatment 4) than in the presence of soil bacteria alone (treatment 2).

How do the data in Figure 1 support the alternative hypothesis that increased use of Bt corn reduces the impact of corn farming on the natural environment?

he toxin in Bt corn kills only the corn pests, leaving other insects unharmed.

The graph indicates that the sheep population most likely is

stable after 1850 under the effects of density-dependent regulating factors

In the Arctic Ocean, the predominant primary producers are phytoplankton. Phytoplankton are consumed by zooplankton, which in turn are eaten by codfish. In years when there is more open water (less ice coverage), there are more zooplankton and fish than in years with less open water (more ice coverage). Based on the graph above, the difference is most likely because

the ice blocks the light, so in years with more ice coverage, there is less photosynthesis by the phytoplankton

The population density at point Q indicates that

the reproductive rate equals the death rate

All of the following are density-dependent factors that limit animal populations EXCEPT

weather