Bio 1B Practice Test

A cow's herbivorous diet indicates that it is a(n) A) primary consumer. B) secondary consumer. C) decomposer. D) autotroph. E) producer.

A

If this were a marine food web, the smallest organism might be A) A. B) F. C) C. D) I. E) E.

A

In general, the total biomass in a terrestrial ecosystem will be greatest for which trophic level? A) producers B) herbivores C) primary consumers D) tertiary consumers E) secondary consumers

A

What is the fundamental difference between matter and energy? A) Matter is cycled through ecosystems; energy is not. B) Energy is cycled through ecosystems; matter is not. C) Energy can be converted into matter; matter cannot be converted into energy. D) Matter can be converted into energy; energy cannot be converted into matter. E) Matter is used in ecosystems; energy is not

A

Which of the following organisms fix nitrogen in aquatic ecosystems? A) cyanobacteria B) chemoautotrophs C) phytoplankton D) legumes E) fungi

A

Which of the following pyramids cannot be inverted? A) production B) biomass C) numbers D) A and B only E) A, B, and C

A

Which of the following terms encompasses all of the others? A) heterotrophs B) herbivores C) carnivores D) primary consumers E) secondary consumers

A

) Long-term ecological research at the Hubbard Brook Experimental Forest indicates that A) intensive logging can dramatically increase levels of nitrate and calcium ions retained in the soil. B) the amount of nutrients leaving an intact forest ecosystem is controlled by the plants themselves. C) selective logging can actually increase species richness in temperate forests. D) A and C only E) A, B, and C

B

Agricultural lands frequently require nutritional supplementation because A) genetically engineered crops require more nutrients. B) the nutrients that enter the plants grown on those lands do not return to that soil. C) the prairies that comprise good agricultural land tend to be nutrient-poor. D) grains raised for feed must be fortified, and thus require additional nutrients. E) both A and B

B

Aquatic ecosystems are unlikely to be limited by insufficient A) nitrogen. B) carbon. C) phosphorus. D) iron. E) sodium.

B

For most terrestrial ecosystems, pyramids of numbers, biomass, and energy are essentially the same-they have a broad base and a narrow top. The primary reason for this pattern is that A) secondary consumers and top carnivores require less energy than producers. B) at each step, energy is lost from the system as a result of keeping the organisms alive. C) as matter passes through ecosystems, some of it is lost to the environment. D) biomagnification of toxic materials limits the secondary consumers and top carnivores. E) top carnivores and secondary consumers have a more general diet than primary producers

B

The total biomass of photosynthetic autotrophs present in an ecosystem is known as A) gross primary productivity. B) standing crop. C) net primary productivity. D) secondary productivity. E) trophic efficiency.

B

To recycle nutrients, the minimum an ecosystem must have is A) producers. B) producers and decomposers. C) producers, primary consumers, and decomposers. D) producers, primary consumers, secondary consumers, and decomposers. E) producers, primary consumers, secondary consumers, top carnivores, and decomposers.

B

Which of the following best explains why energy cannot cycle through an ecosystem? A) the law of conservation of energy B) the second law of thermodynamics C) the competitive exclusion principle D) the green world hypothesis E) the principle of biomagnification

B

Which of the following statements is correct about biogeochemical cycling? A) The phosphorus cycle involves the rapid recycling of atmospheric phosphorus. B) The phosphorus cycle is a sedimentary cycle that involves the weathering of rocks. C) The carbon cycle is a localized cycle that primarily reflects the burning of fossil fuels. D) The carbon cycle has maintained a constant atmospheric concentration of CO2 for the past million years. E) The nitrogen cycle involves movement of nitrogen very little of which is chemically altered by either the biotic or abiotic components of the ecosystem.

B

How is it that the open ocean produces the highest net primary productivity of Earth's ecosystems, yet net primary productivity per square meter is relatively low? A) It contains greater concentrations of nutrients. B) It receives a greater amount of solar energy per unit area. C) It has the greatest total area. D) It contains more species of organisms. E) Its producers are generally much smaller than its consumers.

C

If the flow of energy in an arctic ecosystem goes through a simple food chain from seaweeds to fish to seals to polar bears, then which of the following is true? A) Polar bears can provide more food for people than seals can. B) The total energy content of the seaweeds is lower than that of the seals. C) Polar bear meat probably contains the highest concentrations of fat-soluble toxins. D) Seals are more numerous than fish. E) The carnivores can provide more food for people than the herbivores can.

C

If you were tracking a nutrient molecule through an ecosystem, which of the following statements would you expect to verify? A) Molecules move through all ecosystems at the same constant rate, as the laws of physics would predict. B) Because of the liquid nature of the aquatic ecosystem, nutrient molecules move through it rapidly compared with forest ecosystems. C) Vertical mixing is essential for high productivity in aquatic ecosystems. D) A and B only E) A, B, and C

C

In the nitrogen cycle, the bacteria that replenish the atmosphere with N2 are A) Rhizobium bacteria. B) nitrifying bacteria. C) denitrifying bacteria. D) methanogenic protozoans. E) nitrogen-fixing bacteria

C

Many homeowners mow their lawns during the summer and collect the clippings, which are then hauled to the local landfill. Which of the following alternatives would cause the least disturbance to local ecosystems? A) Don't mow the lawn-have sheep graze it and put the sheep's feces into the landfill. B) Collect the clippings and burn them. C) Either collect the clippings and add them to a compost pile, or don't collect the clippings and let them decompose on the lawn. D) Collect the clippings and wash them into the nearest storm sewer that feeds into the local lake. E) Dig up the lawn and cover the yard with asphalt.

C

Subtraction of which of the following will convert gross primary productivity into net primary productivity? A) the energy contained in the standing crop B) the energy used by heterotrophs in respiration C) the energy used by autotrophs in respiration D) the energy fixed by photosynthesis E) all solar energy

C

The high levels of pesticides found in birds of prey is an example of A) eutrophication. B) predation. C) biological magnification. D) the green world hypothesis. E) chemical cycling through an ecosystem.

C

) When levels of CO2 are experimentally increased, C3 plants generally respond with a greater increase in productivity than C4 plants. This is because A) C3 plants are more efficient in their use of CO2. B) C3 plants are able to obtain the same amount of CO2 by keeping their stomata open for shorter periods of time. C) C4 plants don't use CO2 as their source of carbon. D) C3 plants are more limited than C3 plants by CO2 availability. E) B and D only.

D

) Which of these ecosystems accounts for the largest amount of Earth's net primary productivity? A) tundra B) savanna C) salt marsh D) open ocean E) tropical rain forest

D

29) If this were a terrestrial food web, the combined biomass of C + D would probably be A) greater than the biomass of A. B) less than the biomass of H. C) greater than the biomass of B. D) less than the biomass of A + B. E) less than the biomass of E.

D

Aquatic primary productivity is often limited by which of the following? A) light B) nutrients C) pressure D) A and B only E) A, B, and C

D

As big as it is, the ocean is nutrient-limited. If you wanted to investigate this, one reasonable avenue would be to A) follow whale migrations in order to determine where most nutrients are. B) observe Antarctic Ocean productivity and compare that to other areas. C) experimentally enrich some areas of the ocean and compare them to unmanipulated areas. D) B and C only E) A, B, and C

D

How does inefficient transfer of energy among trophic levels influence the typically high risk of extinction shared by most top predators? A) Predators are sparsely distributed. B) Predators have relatively small population sizes. C) Predators are more disease-prone than animals at lower trophic levels. D) A and B only E) A, B, and C

D

Nitrogen is available to plants only in the form of A) ammonium. B) nitrite. C) nitrate. D) A and C only E) A, B, and C

D

Organisms in which of the following groups can be primary producers? A) cyanobacteria B) zooplankton C) flowering plants D) A and C only E) A, B, and C

D

Some aquatic ecosystems can have inverted biomass pyramids because A) phytoplankton are much larger than zooplankton. B) phytoplankton have a relatively short life cycle. C) consumption of phytoplankton by zooplankton is so rapid that the standing crop of phytoplankton remains relatively low. D) B and C only E) A, B, and C

D

The difference between net and gross primary productivity would likely be greatest for A) phytoplankton in the ocean. B) corn plants in a farmer's field. C) prairie grasses. D) an oak tree in a forest. E) sphagnum moss in a bog.

D

Which of the following are responsible for most of the conversion of organic materials into CO2, which can be utilized in primary production? A) autotrophs B) bacteria C) fungi D) B and C only E) A, B, and C

D

Which of the following statements about energy flow is incorrect? A) Secondary productivity declines with each trophic level. B) Only net primary productivity is available to consumers. C) About 90% of the energy at one trophic level does not appear at the next. D) Eating meat is probably the most economical way of acquiring the energy of photosynthetic productivity. E) Only about one-thousandth of the chemical energy fixed by photosynthesis reaches a tertiary-level consumer.

D

Which of these ecosystems has the highest net primary productivity per square meter? A) savanna B) open ocean C) boreal forest D) tropical rain forest E) temperate forest

D

All of the following are likely results of land-clearing operations such as deforestation and agricultural activity except A) destruction of plant and animal habitats. B) erosion of soil due to increased water runoff. C) leaching of minerals from the soil. D) rapid eutrophication of streams and lakes. E) decreased carbon dioxide in the atmosphere.

E

Burning fossil fuels releases oxides of sulfur and nitrogen. Ultimately, these are probably responsible for A) the death of fish in Norwegian lakes. B) rain with a pH of 3.0. C) calcium deficiency in soils. D) B and C only E) A, B, and C

E

How does phosphorus normally enter the atmosphere? A) respiration B) photosynthesis C) rock weathering D) geological uplifting (subduction and vulcanism) E) It does not enter the atmosphere in biologically significant amounts.

E

Human-induced modifications of the nitrogen cycle can result in A) eutrophication of freshwater ecosystems. B) increased availability of fixed nitrogen to primary producers. C) accumulation of toxic levels of nitrates in groundwater. D) A and C only E) A, B, and C

E

If you wanted to convert excess grain into the greatest amount of animal biomass, to which animal would you feed the grain? A) chickens B) mice C) cattle D) carp (a type of fish) E) mealworms (larval insects)

E

Production, consumption, and decomposition are important ecosystem processes. Which of the following could be decomposers? A) bacteria B) vertebrates C) invertebrates D) A and C only E) A, B, and C

E

The amount of chemical energy in consumers' food that is converted to their own new biomass during a given time period is called A) biomass. B) standing crop. C) biomagnification. D) primary production. E) secondary production

E

The main decomposers in an ecosystem are A) fungi. B) plants. C) insects. D) prokaryotes. E) both A and D

E

The producers in ecosystems include organisms in which of the following groups? A) prokaryotes B) algae C) plants D) B and C only E) A, B, and C

E

Trophic efficiency is A) the ratio of net secondary production to assimilation of primary production. B) the percentage of production transferred from one trophic level to the next. C) the ratio of net production at one trophic level to the net production at the level below, expressed as a percentage. D) usually greater than production efficiencies. E) both B and C

E

Which of the following is primarily responsible for limiting the number of trophic levels in most ecosystems? A) Many primary and higher-order consumers are opportunistic feeders. B) Most predators require large home ranges. C) Nutrient cycles involve both abiotic and biotic components of ecosystems. D) Nutrient cycling rates tend to be limited by decomposition. E) Each energy transfer is less than 100% efficient.

E

Which of the following situations is consistent with the green world hypothesis? A) Milkweed plants are eaten by monarch caterpillars. B) Some gypsy moths cannot feed and thus die because others moths have defoliated the trees in the area. C) Webworms cooperate with each other to build a protective silken structure around themselves. D) A mild winter improves the survival rate of overwintering cutworms. E) Grasshoppers in a corn field are killed by a viral infection

E

Which of the following statements is (are) true? A) An ecosystem's trophic structure determines the rate at which energy cycles within the system. B) At any point in time, it is impossible for consumers to outnumber producers in an ecosystem. C) Chemoautotrophic prokaryotes near deep-sea vents are primary producers. D) There has been a well-documented increase in atmospheric carbon dioxide over the past several decades. E) both C and D

E

You have a friend who is wary of environmentalists' claims that global warming could lead to major biological change on Earth. Which of the following statements can you truthfully make in response to your friend's suspicions? A) We know that atmospheric carbon dioxide has increased in the last 150 years. B) Through measurements and observations, we know that carbon dioxide and temperature were correlated even in prehistoric times. C) Global warming could have significant effects on United States agriculture. D) A and C only E) A, B, and C

E