APES Community Interactions - Study Guide

Directions: Select the choice that best fits each statement. The following question(s) refer to the following possible relationships between organisms in an ecosystem. (A) Commensalism (B) Parasitism (C) Mutualism (D) Predation (E) Competition Exemplified by moss growing on a tree trunk in a forest A Commensalism B Parasitism C Mutualism D Predation E Competition

A Commensalism

Which of the following is the best example of a keystone species? A Sea otter B Sea urchin C Spotted owl D Snail darter E Condor

A Sea otter

A 163 square-kilometer (km2) small island is found 2,000km from the mainland. A second, larger, 230,000km2 island is found 1,000km from the mainland. Based on the theory of island biogeography, which of the following statements is most likely true about the small island when compared with the large island? A The rate of immigration is lower for the small island than for the large island. B The small island has niches that are more like the mainland than the large island. C The small island has more available resources than the large island. D The rate of species extinction is lower on the small island than on the large island.

A The rate of immigration is lower for the small island than for the large island. - More species would migrate to this large island over the small one since the large island is closer and larger.

Intra-specific competion is considered to be more intense than Inter-specific competition, which statement BEST explains why this is? A Their niches overlap 100% B They have similar but not same adatations such as bill type C They typically have different habitats D They migrate to the same places throughout the year

A Their niches overlap 100%

Based on the theory of island biogeography, which of the following is the most likely reason that an island in the ocean that is 5 kilometers from a continent would have a higher number of species than one that is 15 kilometers from a continent? A There are more species that have the ability to travel 5 kilometers than can travel 15 kilometers. B Islands that are closer to continents always have a wider range of habitats than more distant islands do. C There are smaller populations of each species on islands that are at greater distances from continents. D Islands that are closer to continents always have more ecological niches than more distant islands do

A There are more species that have the ability to travel 5 kilometers than can travel 15 kilometers. - It takes less energy and potentially less complicated locomotion to travel 5 kilometers than it does 15 kilometers, so more species are able to travel 5 kilometers than 15 kilometers.

You are an evolutionary entomologist. You have observed beetles who can raise their abdomens and give off a defensive chemical that generally repels predators. You discover a new species of beetle that raises its abdomen in a threatening way similar to the first species, but no defensive chemical is given off. You are most likely to characterize this defensive strategy as a form of A mimicary B predation C poisonious D camoflauge

A mimicary

At which time after clear-cutting does the ecosystem exhibit the greatest species richness? A 50 years B 100 years C 150 years D 200 years E 250 years

B 100 years

The graphs above show the population size and distribution of beak sizes in a finch population on the island of Daphne Major in the Galapagos in 1976 and 1978. Smaller-beaked finches are better suited for eating grasses and small seeds. Larger-beaked finches are better suited for cracking larger seeds and nuts. In 1977 a drought took place and the vegetation of the island was affected by the lack of rain. Which of the following was the average beak size of finches on the island of Daphne Major in 1976? A 8.8 mm B 9.5 mm C 10.2 mm D 13.8 mm

B 9.5 mm - This average beak size for the population in 1976 is 9.5 mm based on the distribution of beak sizes in the graph. It is also noted with a dashed line.

Highly specialized species tend to evolve on islands because of the environmental conditions and resource availability. Based on the theory of island biogeography, which of the following would most likely experience the greatest decline of specialist species if an invasive species emigrated from the mainland? A A small island a far distance from the mainland B A small island in close proximity to the mainland C A large island a far distance from the mainland D A large island in close proximity to the mainland

B A small island in close proximity to the mainland - Being close to the mainland increases immigration of species. A small island has fewer niches available and specialized food webs, which is most likely to cause substantial declines in specialist species.

Little is known about Africa's elusive aardvarks, but new research says they are vulnerable to climate change like many other species. Hotter temperatures are taking their toll on the aardvark, whose diet of ants and termites is becoming scarcer in some areas because of reduced rainfall. Drought in the Kalahari Desert killed five out of six aardvarks that were being monitored for a year, as well as 11 others in the area. The aardvarks' body temperatures plummeted during the night because they were not getting enough energy from diminished food sources. They tried to conserve energy by looking for insects during the warmer daytime, but their efforts to adapt could not save them. Researchers said some birds, reptiles and other animals use aardvark burrows to escape extreme temperatures, reproduce, and hide from predators. They could have fewer refuges available if aardvark populations shrink because of rising temperatures, they said. The aardvark, which lives in many parts of sub-Saharan Africa, is identified as an animal of "least concern" on an international "red list" of threatened species. There are no indications that the population is changing significantly in southern Africa, though it is speculated that numbers may be declining elsewhere because of habitat destruction, the bushmeat trade and other factors. "Study Finds aardvarks suffering as African climate heats up," Christopher Torchia, Phys.org, July 31, 2017. Which of the following best identifies the author's claim? A Aardvarks are shifting the location of their territories as a response to global climate change. B Aardvarks are a keystone species and their decline could have a trophic cascade effect on the ecosystem. C The loss of aardvarks described in the study was an isolated incident because most aardvark populations are increasing globally. D Providing aardvarks with more burrows will help them maintain their body temperature and increase survival rates.

B Aardvarks are a keystone species and their decline could have a trophic cascade effect on the ecosystem. - The article states that many other species use burrows dug by aardvarks, indicating that a decline in aardvark numbers will have dramatic negative effects. Aardvarks are considered a keystone species because they play a critical role in the way the ecosystem functions

The next questions are based on the following table of organisms in an ecological community. The X in a cell indicates that the organism is eaten by the consumer in the first column. Based on the data in the table, which of the following pairs of organisms has two ecological relationships, both competition and predation? A Spiders and shrews B Hawks and snakes C Spiders and snakes D Spiders and grasshoppers

B Hawks and snakes - Hawks and snakes both eat shrews, so they compete for food. Hawks are also predators of snakes.

Which of the following best describes a symbiotic relationship? A Striped bass and bluefish eat the same variety of mackerel. B Intestinal bacteria inhabit the gut of humans. C Mountain lions feed on white-tailed deer. D Marsupial animals carry their young in a pouch.

B Intestinal bacteria inhabit the gut of humans.

A North Carolina timber company proposes to clear-cut 45 hectares of oak-hickory deciduous forest in the Appalachian Mountains. The company has said that the forest will regrow naturally, and 50 years after the clear-cutting the company plans to harvest again, cutting all the oaks and hickories that have at least a 40-centimeter diameter. A local citizens' group claims that this is not a realistic plan. Which of the following, if true, best supports the claim of the citizens' group? A Harvesting oak and hickory will disrupt the soil in the first year after clear-cutting; oaks and hickories cannot germinate that first year. B Oak and hickory are late-successional species; pioneer species will dominate for many decades before the oaks and hickories are reestablished. C Coniferous forests can regrow after having been clear-cut; the biome will change to a boreal forest after clear-cutting. D Populations of large carnivores in the forest will decline after clear-cutting occurs; deer hunting will suffer as a result. E Erosion rates on the slopes of the Appalachian Mountains will decrease after clear-cutting; many new species will move into the forest.

B Oak and hickory are late-successional species; pioneer species will dominate for many decades before the oaks and hickories are reestablished.

Directions: Select the choice that best fits each statement. The following question(s) refer to the following possible relationships between organisms in an ecosystem. (A) Commensalism (B) Parasitism (C) Mutualism (D) Predation (E) Competition Exemplified by ticks feeding on a deer A Commensalism B Parasitism C Mutualism D Predation E Competition

B Parasitism

In a typical forest ecosystem, dead trees and fallen trees are most important because of their role in which of the following? A Providing a valuable source of timber B Providing habitats for wildlife C Contributing to soil erosion D Increasing water runoff E Removing carbon dioxide from the air

B Providing habitats for wildlife

Species such as Wolves and Beavers whose roles in an ecosystem are much more important than their abundance would suggest are called? A Symbiotic B Competitors C Keystone D Alturistic E none of the above

C Keystone

Directions: Select the choice that best fits each statement. The following question(s) refer to the following possible relationships between organisms in an ecosystem. (A) Commensalism (B) Parasitism (C) Mutualism (D) Predation (E) Competition Exemplified by bees consuming nectar and carrying pollen from one flower to another A Commensalism B Parasitism C Mutualism D Predation E Competition

C Mutualism

Based on the data shown in the graph, which of the following best describes how ecologists could determine when this ecosystem is approaching a climax community? A Determine if the keystone species in the ecosystem is present two years after the volcanic eruption B Measure the biomass of the pioneer species present before and after the volcanic eruption C Record the number and type of producers present every year after the eruption D Calculate the net primary productivity of a specific indicator species every year after the eruption

C Record the number and type of producers present every year after the eruption - A high number of late successional plant species would indicate that the ecosystem is approaching a climax community.

Five different species of warblers, seed-eating birds, live in the same species of conifer trees. All of the birds migrate to coniferous forests during the summer, and different species reside in different areas in the same tree. They feed on the seeds of the conifer trees, but the different species do not mate with each other. Which of the following best explains why the different warbler species can all have habitats in the same conifer trees? A Not all the warblers are residents in the forest at the same time of the year because of different migration patterns. B Physiological differences in beak structure allow the warblers to consume different species of seeds through symbiotic relationships. C Resource partitioning of the seeds reduces competition, and the five different species can live in the same tree. D Niche overlap occurs between the five different species, and living in the same tree increases competition for seeds.

C Resource partitioning of the seeds reduces competition, and the five different species can live in the same tree. - The warblers are using the same resource (tree) in slightly different places, and since they are not feeding in the same place, this reduces competition. This concept is known as resource partitioning.

Which of the following best explains why decomposers in soils and water are important to ecosystems? A They remove heavy metals. B They store carbon dioxide. C They recycle nutrients. D They neutralize acid deposition. E They produce more oxygen than they consume.

C They recycle nutrients.

An organism's niche is analogous to its A habitat B physical environment C role in system D adapatations E none of the above

C role in system

The diagrams above show the range of tolerance for soil moisture content for two different species of terrestrial invertebrate: Species 1 and Species 2. The ranges represented are for each species where it occurs alone. Soil moisture content is a limiting factor for both species. If populations of both species are placed together in a new location, which of the following diagrams represents the most likely actual (realized) ranges of the species' distribution of individuals with respect to soil moisture content after five generations? A B C D E

D

This biome contains plants that are adapted to prevent water loss due to the low average rainfall and high temperatures year-round. A Savanna B Boreal forest C Tropical rain forest D Desert

D Desert - Deserts are hot and dry year-round, and plant species are adapted in a variety of ways (small leaves, stems that store water, and modified spines) to reduce water loss.

Which of the following best illustrates an abiotic component of the environment affecting a biotic component of the environment? A Composted manure is added to agricultural soil during spring tilling. B Coral reefs modify the direction of an ocean current. C Plants release O2 into the atmosphere during photosynthesis. D Low phosphorus content in soil limits the growth of vegetation. E A thick planting of ground cover reduces soil erosion on a hillside.

D Low phosphorus content in soil limits the growth of vegetation.

Which tree species grows best with full sunlight? A White oak B Hickory C Dogwood D Sweet gum E Beech

D Sweet gum

The graphs above show the population size and distribution of beak sizes in a finch population on the island of Daphne Major in the Galapagos in 1976 and 1978. Smaller-beaked finches are better suited for eating grasses and small seeds. Larger-beaked finches are better suited for cracking larger seeds and nuts. In 1977 a drought took place and the vegetation of the island was affected by the lack of rain. Which of the following statements best explains the changes in the size and composition of the population of finches after the drought? A The total number of finches in the population increased, and the smaller-beaked finches were more successful in the drier environment. B The total number of finches in the population increased, and the larger-beaked finches were more successful in the drier environment. C The total number of finches in the population decreased, and the smaller-beaked finches were more successful in the drier environment. D The total number of finches in the population decreased, and the larger-beaked finches were more successful in the drier environment.

D The total number of finches in the population decreased, and the larger-beaked finches were more successful in the drier environment. - The population total decreased from 751 to 90 finches, and the proportion of larger-beaked finches to smaller-beaked finches increased because the larger-beaked finches were better able to find food (more hard seeds and nut after the drought).

The graph below shows the results obtained when two species of Paramecium were grown together in the same medium. The graph above best exemplifies A the demographic transition B sustained logarithmic growth C the edge effect D competitive exclusion E the normal distribution

D competitive exclusion

Directions: Select the choice that best fits each statement. The following question(s) refer to the following possible relationships between organisms in an ecosystem. (A) Commensalism (B) Parasitism (C) Mutualism (D) Predation (E) Competition Exemplified by starlings displacing bluebirds from nesting sites A Commensalism B Parasitism C Mutualism D Predation E Competition

E Competition

Directions: Each of the questions or incomplete statements below is followed by five suggested answers or completions. Select the one that is best in each case. A one-hectare pond is sampled in early September. The sample yields 1 small catfish as well as 17 benthic invertebrates that represent 10 species. If the pond is resampled a year later, which of the following would best indicate that the pond had been adversely affected by adjacent development? A An uncommon species has become more numerous. B An increase in low-tolerance species has occurred. C A decrease in high-tolerance species has occurred. D Phylogenetic diversity has increased. E The biodiversity of the pond has decreased.

E The biodiversity of the pond has decreased.

Inter-specific competition can be avoided by? A being active at different times of day B eating different food resources C niche partioning D physical adaptations E all of the above

E all of the above

Prey populations that use large body size to defend against predation most likely do which of the following? A use mimicry B use warning coloration C use venom D speed and agility to avoid predation E protect their young

E protect their young