Unit 7 Practice Exam

  1. When sea otters become extremely rare on the California coast, their usual prey (sea urchins) became overabundant and consumed most of the kelp that was the principal habitat for a diversity of fishes and invertebrates. Which statement best describes this situation?
  1. This is an example of mutualism between sea urchins and sea otters
  2. Sea otters are keystone species
  3. Sea urchins are keystone species
  4. Sea urchins are parasitic on kelp
  1. The combination of conditions that a species can tolerate in the presence of competitors is a ______.
  1. Niche overlap
  2. Fundamental niche
  3. Realized niche
  4. Niche differentiation
  1. What is true of the theory of island biogeography?
  1. Immigration rates should be lower on small islands far from land than on large islands close to land
  2. Speciation rates balance extinction rates
  3. Immigration rates should be higher on small islands far from land
  4. It only applies to oceanic islands
  1. Which of the following is an example of a parasite manipulating its host?
  1. Ants harvesting honeydew from treehoppers and protecting them from spiders
  2. Ants living in special structures in acacia trees and defending the trees
  3. Cleaner shrimp removing parasites from the gills of fish
  4. A nematode causing infected ants to display their reddened posterior area, raising the possibility of bird predation.
  1. All else being equal, which island is expected to have a higher species richness?
  1. Recently created volcanic islands are expected to have more species than older islands
  2. Smaller islands are expected to have more species richness
  3. More remote (farther from mainland) islands will have higher species richness
  4. Islands at lower latitudes are expected to have more species richness
  1. Which example supports the hypothesis that predators hold populations below carrying capacity?
  1. In communities where predators are rare, the prey population is also rare
  2. Wolf predation has no effect on the prey population
  3. A wolf control program in Alaska decreased the abundance of wolves to 55% to 80% below pre-control density. During this time period, the moose population tripled
  4. Predators that prey on the young and individuals of reproductive age are shown to have less impact on the prey population than predators that target the old and sick
  1. Which of the following statements describes a response of predators to prey?
  1. Moose are capable of killing of maiming wolves by licking them
  2. A hoverfly mimics a wasp
  3. A species of fish takes the appearance of its surroundings
  4. A species of fish hides in a hole until another fish swims past that it can attack and eat
  1. Which of the following would you predict for a species of barnacle if defenses are inducible?
  1. Shell thickness decreases and attachment strength remains the same in areas of high predation
  2. Shell thickness remains the same and attachment strength increases in areas of high predation
  3. Shell thickness increases and attachment strength remains the same in areas of high predation
  4. Shell thickness and attachment strength increase in areas of high predation
  1. Which interaction belongs in the +/- category of interactions between species?
  1. Commensalism
  2. Pollination
  3. Mutualism
  4. Parasitism
  1. Which is an example of Mullerian mimicry?
  1. Some frogfish look extremely similar to sponges, corals, or algae and are therefore difficult to spot.
  2. The harmless bee fly looks very much like a stinging wasp
  3. Many different species of stinging wasps look very similar, with black and yellow banded bodies
  4. Certain vegetarian species of Australian possums look very much like vegetarian squirrels or lemurs
  1. Which of the following describes the pattern of tree species richness?
  1. There is no relationship between tree species diversity and latitude
  2. Tree species diversity increases with decreasing latitude
  3. Tree species diversity increases with increasing latitude
  4. Tree species diversity decreases with increasing latitude and longitude
  1. You notice an interaction between two species. Removal of either species results in decreased fitness of the other species. What kind of interaction do these species normally have?
  1. Consumption
  2. Commensalism
  3. Mutualism
  4. Competition
  1. What event would be considered primary succession?
  1. The logging of an area leaves only the soil
  2. Following a succession event, a specific sequence of species begins to appear
  3. A landslide causes the removal of the soil and the organisms that live in the area, leaving the rock exposed
  4. A flood removes all the mammals from an area
  1. Birds that follow moving ants in tropical forests benefit by catching prey that jumps out of the ants’ path. The ants are unaffected by the birds behavior. This interaction is an example of
  1. Competition
  2. Consumption
  3. Commensalism
  4. Mutualism
  1. In many parts of North America, Alliariapetiolata (garlic mustard) is an invasive plant species. Garlic mustard secretes chemicals from its roots that inhibit the growth of other plant species. If, over time, other plants evolve defenses to resist the toxic chemical, then _____ has occurred.
  1. Intraspecific competition
  2. Mutualism
  3. Coevolution
  4. Secondary succession
  1. Which of the following statements about competition is true?
  1. The principle of competitive exclusion allows species with the same niche to coexist
  2. Competitors can coexist by developing ways to benefit the other species
  3. When two competitors have slightly different fundamental niches, the pooror competitor can take refuge in areas that are beyond the better competitors tolerance
  4. Competition never leads to the complete exclusion of one species.
  1. Which of the following is an example of ecosystem studies?
  1. How species interact with an ecosystem
  2. Study of behavioral interactions of predators and prey
  3. Changes in the abundance of a species through time
  4. How the energy in sunlight dissipates as it flows through an ecosystem
  1. Which of the following is true about the components of ecosystems?
  1. Secondary consumers are in the second trophic level
  2. All autotrophs use the Sun’s energy to produce chemical energy
  3. Primary producers are autotrophs or “self-feeders”
  4. Primary consumers are organisms that feed on dead organisms and their waste products
  1. Which of the following is true or net primary productivity?
  1. Deserts and arctic regions have the highest productivity
  2. Temperate areas are more productive than tropical areas
  3. There is no productivity in the depths of oceans
  4. Marine productivity is highest along coasts and in areas where water wells up from the ocean bottom to the surface
  1. Which organisms would be found in the same trophic level?
  1. A pack of wolves and a herd of deer
  2. A plant and an herbivore
  3. Pine trees and garden snakes
  4. Crickets and cows
  1. Which of the following is true of biomagnification?
  1. Biomagnification is more likely to occur for compounds that are easily excreted by consumers
  2. Biomagnification is not an environmental problem
  3. The concentration of toxin can more than double at each level of the food chain
  4. Biomagnification is only a problem in terrestrial environment because the ocean dilutes toxins to a negligible level
  1. Of the many links in a nutrient cycle, which one most often limits the overall rate at which nutrients move through an ecosystem?
  1. Decomposition of detritus
  2. Plant nutrient uptake and conversion to tissue
  3. Plant and animal death and their addition to the dead biomass
  4. Animal consumption and conversion to tissue
  1. The global carbon cycle involves the movement of carbon among ecosystems. Which of the following is the largest pool of carbon?
  1. The atmosphere
  2. Human-induced changes
  3. Terrestrial ecosystems
  4. The ocean
  1. Which of the following statements about biogeochemical cycles is true?
  1. Nutrients remain in an animal until the animal’s death
  2. Nutrients are taken up directly from soil by animals and incorporated into their tissues
  3. Nutrients cannot move from one trophic level to a higher trophic level the way energy can
  4. If a plant dies, the nutrients and the plant biomass become litter
  1. Which of the following statements about food webs is true?
  1. A food web depicts a single species as it changes demographically
  2. Several species can be present in each trophic level
  3. The overall average number of trophic levels found in a food web is about seven
  4. Food webs show which species are keystone species
  1. The energy invested in the production of new tissue by autotrophic organisms is termed _____.
  1. Gross photosynthetic efficiency
  2. Net primary productivity
  3. Gross primary productivity
  4. Maintenance
  1. Humans have substantially altered the global nitrogen cycle over the past century. How?
  1. Global warming has reduced the conversion of nitrogen gas to ammonium and other ionic forms
  2. Humans have dramatically increased nitrogen availability as a side effect of internal engine fuel combustion
  3. The number of gigatons of nitrogen produced has declined in recent years
  4. Humans are now responsible for almost doubling the amount of nitrogen available by natural means
  1. Several major human impacts on ecosystems are farming, logging, burning, and soil erosion. These processes all result in accelerated nutrient loss by what common mechanism?
  1. Environmental pollution
  2. Loss of animal habitat
  3. Soil compaction
  4. Vegetation removal
  1. Why are changes in the global carbon cycle important?
  1. Less atmospheric carbon means that there are less fossil fuels available
  2. Carbon dioxide is a greenhouse gas
  3. More atmospheric carbon dioxide means that there is less carbon available for the growth of terrestrial plants
  4. The global carbon cycle is the only factor affecting Earth’s climate
  1. How does NPP differ from GPP?
  1. NPP is the amount of energy available at each trophic level, whereas GPP is the sum of all the NPPs.
  2. NPP is dependent on climate, whereas GPP is an intrinsic attribute of the species producing energy
  3. NPP is the amount of productivity available for decomposers
  4. NPP is the amount available for primary consumers, whereas GPP is the amount produced by plants and other producers
  1. Which of the following statements about human impacts on Earth is true?
  1. Until the twentieth century, most species extinctions occurred on continents and were caused by overhunting and introduced species
  2. Newly threatened species are at risk from deforestation and other forms of habitat destruction
  3. Most newly threatened species live on islands
  4. Species introduced by humans are not a serious threat to biodiversity, and in fact they increase levels of biodiversity
  1. Which of these statements about endemic birds is true?
  1. Areas with the highest species richness of birds are evenly distributed in the tropics.
  2. The highest species richness occurs in tropical islands
  3. The highest species richness occurs in the Andes
  4. Areas with the lowest species richness of birds are evenly distributed in the temperate zone
  1. What is the effect of biodiversity on ecosystem productivity?
  1. Decreased biodiversity increases productivity
  2. Increased biodiversity increases productivity
  3. Sometimes biodiversity increases productivity, and sometimes it decreases productivity
  4. Because productivity is increased with higher biodiversity, there will be pressure to evolve new species in where biodiversity is low
  1. When scientists count species in a region, they are studying ______.
  1. Species diversity
  2. Genetic diversity
  3. Ecosystem diversity
  4. Species richness
  1. Humans are causing species extinctions. Which taxonomic group has the highest percentage of threatened species?
  1. Mammals
  2. Birds
  3. Amphibians
  4. All of these groups have similar percentages of threatened species
  1. The species-area relationship can estimate the rate of extinction based on projections of ______.
  1. Climate change impacts
  2. Human population growth
  3. Habitat destruction
  4. Invasive species introductions to an area
  1. What makes conservationists consider red pandas especially important to save from extinction?
  1. They have relatively large body size
  2. They occur in the middle of phylogenetic trees
  3. They lack close relatives and represent a highly distinct lineage
  4. They only occur in China
  1. Researchers set out to catalog all the angiosperms present in a state park. This is an example of ______.
  1. Environmental sequencing
  2. An all-taxa survey
  3. A taxon-specific survey
  4. Habitat destruction
  1. Which process results directly in habitat destruction?
  1. Introducing invasive species
  2. Pollution
  3. Damming rivers
  4. Overhunting
  1. What is a characteristic of habitat fragmentation?
  1. It is higher in areas uninhabited by people
  2. It results in higher species diversity
  3. Species that prefer habitat edges do better than species that prefer habitat interiors
  4. Species that were formed by geographic separation (allopatric species) are more successful