Unit 1
Based on the second law of thermodynamics, how much biomass of phytoplankton would be needed to produce 1 kilogram (kg) of large fish in this food web?
1,000 kg
In a given ecosystem, producers convert solar energy into 15,000kcal of chemical energy stored in organic compounds. Which of the following is the most likely amount of energy available to secondary consumers?
150 kcal
A temperate grassland biome has a gross primary productivity of 3,480kilocalories/meter2/year and a net primary productivity of 2,000kilocalories/meter2/year. Which of the following is the approximate number of kilocalories/meter2/year available to herbivores in that biome?
200kilocalories/meter2/year
Which of the following best explains why terrestrial trophic pyramids usually do not have levels higher than tertiary consumers?
A large proportion of energy is lost as heat as it is transferred up the pyramid, so there is not enough energy available to support another level.
The largest area of old-growth forest in the United States is located in ______?
Alaska
Predation
An interaction in which one organism captures and feeds on another organism
The following question(s) refer to the following processes. (A) Nitrification (B) Denitrification (C) Assimilation (D) Ammonification (E) Nitrogen fixation Plant roots absorb ammonium ions and nitrate ions for use in making molecules such as DNA, amino acids, and proteins.
Assimilation
Which of the following types of organisms are required to complete the nitrogen cycle, including the process of denitrification?
Bacteria
A field is abandoned, and an invasive plant that can live in nutrient-poor soil moves into the field. If the land is later cleared of this invasive species and it is discovered that the soil has an abundance of nitrogen compounds, what conclusion can best be made?
Bacteria in soil and in root nodules converted free nitrogen into nitrogen compounds.
Which of the following world regions contain the greatest area of rain forest?
Brazil and Indonesia
What represents a carbon source?
Burning fossil fuels - It is a source because it releases carbon that has been stored in coal, oil, or natural gas, which are carbon sinks.
How does the burning of fossil fuels contribute to the net increase in atmospheric carbon?
Carbon that has been sequestered underground is added to the carbon cycling between the atmosphere and the biosphere.
This rate of reaction can be measured in the dark by determining the amount of oxygen gas consumed in a period of time.
Cellular respiration
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
Commensalism
This biome is found in shallow waters off the coastline and is Earth's most biologically diverse marine biome.
Coral reefs
Which process most directly results in the storage of carbon as coal and oil over millions of years?
Decomposition
Which process in the nitrogen cycle releases nitrogen gas into the atmosphere?
Denitrification of soil nitrates by bacteria
Which of the following pathways indicate how nitrogen is added to the largest nitrogen reservoir?
Denitrifying bacteria and volcanic activity
This biome contains plants that are adapted to prevent water loss due to the low average rainfall and high temperatures year-round.
Desert
Which of the following best describes the movement of energy in an ecosystem?
Energy is harnessed by producers, and available energy decreases with each trophic level transfer.
Which of the following processes leads to precipitation?
Evaporation rate
Scientists calculated the net primary productivity at two different forest sites. Both forests have the same gross primary productivity. Forest AA has a net primary productivity of 1,650kcal/m2/year, and forest BB has a net primary productivity of 1,110kcal/m2/year. Which of the following statements is best supported by the data?
Forest A producers have lower rates of cellular respiration than forest B producers.
Which of the following statements is true of aquatic biomes?
Freshwater biomes are a vital source of drinking water.
This biome contains a nutrient-rich environment created by falling leaves and trapped organic materials from the large trees, and it provides the ecosystem service of filtering pollutants from water.
Freshwater wetlands
The total rate of photosynthesis in a given area.
Gross primary productivity
Which of the following best describes gross primary productivity in an ecosystem?
Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.
Which of the following major reservoirs of freshwater are missing from the diagram?
Ice caps
Energy is transferred along food chains from one stage to the next. Which statement best explains how the energy is transferred?
If a primary producer stores 10,000kcal of energy, then a tertiary consumer will have 10kcal of energy available.
What is the part of the hydrologic cycle that is most directly affected by impervious building materials, such as concrete and asphalt?
Impervious materials directly decrease the amount of water infiltration and increase the amount of runoff.
The diagrams above show an area that was once a pasture that has since undergone changes to the vegetation over time. Which of the following changes in the hydrologic cycle is most likely to occur as a result of the change in vegetation in the area?
Increased infiltration
Which of the following biomes is best characterized as an area that forms the narrow band along the coast that experiences a range of environmental conditions (including daily changes in sunlight, temperature, and water) ?
Intertidal zones
Which of the following best describes a symbiotic relationship?
Intestinal bacteria inhabit the gut of humans.
Which trophic level has the least available energy in kilojoules in this food web?
Killer whale
In reef ecosystems, corals often have microalgae living inside them. The algae supply the corals with nutrients, and the coral give shelter to the algae. Which of the following interactions best describes the relationship between the corals and the algae?
Mutualism
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
Mutualism
The energy available to consumers determined by subtracting the energy used by plants from the total energy transformed by the process of photosynthesis.
Net primary productivity
Which of the following best describes the net primary productivity of an ecosystem?
Net primary productivity is the amount of energy lost through respiration by producers subtracted from the gross primary productivity of an ecosystem.
Which of the following processes is illustrated by the downward arrows from the atmosphere that show the conversion of nitrogen gas into usable forms available to producers?
Nitrogen fixation
Which of the following elements is most likely to limit primary production in freshwater lakes?
Phosphorus
What is a similarity between phosphorous and nitrgoen?
Phosphorus and nitrogen are both required for plant growth.
What reduces the amount of carbon dioxide in the atmosphere?
Photosynthesis
Which of the following trophic levels represents a primary producer in an aquatic food chain?
Phytoplankton
Which of the following best describes the flow of energy in most terrestrial and near-surface marine ecosystems?
Producers use energy from the sun to make organic matter, such as sugars, from carbon dioxide and water and are then consumed by organisms higher in the food chain.
In a typical forest ecosystem, dead trees and fallen trees are most important because of their role in which of the following?
Providing habitats for wildlife
The movement of phosphorus between biological organisms and soil is in a steady state in an undisturbed system, why?
Readily available organic phosphorus in the soil is assimilated by plants.
Two bird species coexist by feeding on the same type of insects in different parts of a tree. One bird species hunts insects near the top of the tree. The other bird species hunts insects near the base of the tree. Which of the following concepts is demonstrated between the two bird species?
Resource partitioning
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?
Resource partitioning of the seeds reduces competition, and the five different species can live in the same tree.
This freshwater biome is characterized by fast-flowing water that can originate from underground springs or runoff, which carries sediment and organic material.
Rivers
The following question(s) refer to the following. (A) Safe Drinking Water Act (B) Clean Water Act (C) Comprehensive Environmental Response Compensation and Liability Act (CERCLA) (D) Resource Conservation and Recovery Act (E) Toxic Substances Control Act Requires minimum safety standards for community water supplies
Safe Drinking Water Act
This biome is characterized by long dry seasons and is dominated by grasses, shrubs, and grazing animals.
Savanna
What continent greatest remaining natural biodiversity?
South America
Which of the following best identifies a key component of the hydrologic cycle that powers the movement of water?
Sun
The majority of the nitrogen on Earth can be found in which of the following reservoirs?
The atmosphere
Which of the following biogeochemical cycles includes the processes of buffering ocean pH and photosynthesis?
The carbon cycle
In a fish species, the number of eggs that hatch and survive for one year varies depending on the number of eggs that were produced. As the number of eggs produced increases past a threshold number, the survival rate of the offspring decreases. Which of the following statements best explains why only a limited number of offspring can survive in a fish population?
The chance of survival decreases when there is intraspecific competition for resources among surviving yearlings.
Which of the following best describes what is represented by the arrows in the food web?
The flow of energy
Which of the following describes the most likely change to terrestrial biomes resulting from warmer average global temperatures?
The global distribution of midlatitude biomes, such as grasslands and temperate rain forests, would increase.
What best describes the most likely direct effect of a decline of the small fish population on the marine food web? (small fish eat jellyfish)
The jellyfish population will increase because of decreased predation.
Which of the following biogeochemical cycles is correctly paired with its largest reservoir?
The nitrogen cycle and the atmosphere
One of the major storage reservoirs of carbon, stored in the form of carbon dioxide is _______?
The ocean
What happens to phosphates in the phosphorous cycle?
The phosphates absorbed by animal tissue through consumption eventually return to the soil.
Six white-tailed deer and six sika deer were enclosed in a pasture for observation during an eight-year study in central Texas. White-tailed deer are a native species to central Texas, while sika deer are a nonnative species to central Texas. White-tailed deer feed on flowering plants and the tips of trees and shrubs but do not eat grass. Sika deer feed on flowering plants, the tips of trees and shrubs, and grass. All other grazing animals were kept out of the pasture during the study. The number of sika deer more than doubled after the eight years, while the population of white-tailed deer decreased by 50 percent.; Which of the following statements best supports the results from the study?
The sika deer out competed the white-tailed deer in consuming flowering plants and shrubs.
Which of the following is the best explanation for why there is such a small amount of phosphorus that moves into aquatic systems?
There is not a gaseous phase of the phosphorus cycle, and therefore the movement of phosphorus into oceanic reservoirs is very slow.
Farmers in a suburban coastal town started using no-till agriculture, a practice that reduces soil erosion from their farmland. Which of the following long-term effects no-till agriculture will have on the ecosystem surrounding the farmland.
There will be less algal growth in the nearby ocean.
Which of the following best describes soil in many tropical rain forests?
They are quickly depleted nutrients when the forest is removed.
The thick forest of this biome tends to be well adapted to short growing seasons.
Tiaga
This biome has the highest net primary productivity, in part because of consistently warm temperatures and abundant sunlight.
Tropical Rainforest
This biome is warm and wet, with little seasonal variation in temperature and frequent precipitation.
Tropical rain forest
Which of the following terrestrial biomes has the highest net primary productivity?
Tropical rain forest
Which of the following terrestrial biomes has the highest primary productivity per unit area?
Tropical rain forest
The following question(s) refer to the qualities of water samples. Acidity Turbidity Hardness Dissolved oxygen Salinity Caused by suspended particulates
Turbidity
Which of the following best describes an example of resource partitioning in an ecosystem?
Two different bird species feed from the same oak tree; one eats acorns, and the other eats insects in the bark.
Which of the following best helps to explain why phosphorus is often a limiting factor in many ecosystems?
Under many conditions, phosphorus forms stable insoluble compounds.
What represents a carbon sink that holds carbon compounds for the shortest period of time?
Vegitation - Carbon dioxide can move into plants to be stored as glucose much more quickly than sedimentary rocks and fossil fuels can be stored. Carbon compounds are held for the shortest amount of time in vegetation
Which of the following best describes a terrestrial ecosystem that will have the highest net primary productivity?
Warm temperatures, high rainfall, and consistent sunlight
One part of the hydraulic cycle includes _____?
Water from the ocean evaporates and condenses in the atmosphere.
Wolves were reintroduced into Yellowstone National Park in 1995. In addition to tracking changes in the wolf population, scientists were interested in how the wolves would affect other parts of the Yellowstone ecosystem. In particular, they were interested in changes to the population of elk, the wolves' primary prey. The graph below shows the population size of the wolf and elk populations over time.; Which of the following is a potential disadvantage of reintroducing wolves to Yellowstone?
Wolves leaving the park may prey on livestock in grazing land outside the park.
Hot and low precipitation leads to ____?
dry scrub with frequent fires
For a primary producer, the main function of photosynthesis is to manufacture
glucose
Steady climate and lots of precipitation leads to ____?
highest diversity of tree species
Open oceans produce the largest share of Earth's biomass because the net primary productivity (NPP) of the oceans is
low, but the large expanse of the oceans supports enormous numbers of producers such as phytoplankton
The major biological source of dissolved oxygen in the ocean comes from
photosynthesis by phytoplankton
Phytoplankton are most abundant in the upper few hundred feet of most bodies of water because
sunlight does not penetrate to great depths in water
Conservation of matter
the principle stating that matter is not created or destroyed during a chemical reaction
Primary productivity
the rate at which energy is converted by photosynthetic and chemosynthetic autotrophs to organic substances
Competition
the struggle between organisms to survive in a habitat with limited resources
