Unit 1 APC

The atmospheric concentration of carbon dioxide increased from 278 ppm in 1790 to 383 ppm in 2007. What is the approximate percent increase in carbon dioxide concentration from 1790 to 2007? A 38% B 50% C 92% D 105% E 138%

A 38%

Measured on the pH scale A Acidity B Turbidity C Hardness D Dissolved oxygen

A Acidity

Which of the following is an example of a carbon sink? A Deposition of organic matter on the deep ocean floor B Clearing of trees in the Amazon forest C Combustion of fossil fuels in power plants D Decomposition of food waste by bacteria E Nutrient uptake by the roots of grasses in a suburban lawn

A Deposition of organic matter on the deep ocean floor

Ammonia is converted to nitrite, then to nitrate. A Nitrification B Denitrification C Assimilation D Ammonification E Nitrogen fixation

A Nitrification

Which of the following is a characteristic of tropical rain forests? A They rarely receive more than 100 centimeters of rain per year. B Their soils typically have a high pH. C Their soils are relatively poor in nutrients. D They do not exhibit a great deal of species diversity. E They generally occur in the rain shadows of mountain ranges.

A They rarely receive more than 100 centimeters of rain per year. B Their soils typically have a high pH. C Their soils are relatively poor in nutrients. D They do not exhibit a great deal of species diversity. E They generally occur in the rain shadows of mountain ranges.

Which of the following best describes the process of leaching? A Water percolating through soil, dissolving some of its material B The falling of acid precipitation from the atmosphere to Earth's surface C The use of chemicals to reduce the amount of E. coli in wastewater D Rocks embedded in a glacier being carried downslope E The use of drip irrigation on a crop of wheat

A Water percolating through soil, dissolving some of its material

Which of the following best describes the movement of energy in an ecosystem? A Energy is constantly recycled by decomposers for use by producers. B Energy is harnessed by producers, and available energy decreases with each trophic level transfer. C Energy is absorbed by plants through water and soil and then moves up the food chain through consumers. D Energy is magnified as it moves up the trophic levels, and tertiary consumers store the most energy in a food web.

Answer B Correct. Energy is harnessed from the sun by producers and is passed through trophic levels. The second law of thermodynamics explains how 90% of energy is lost between trophic levels.

Where is the majority of fresh water found on Earth? A Groundwater B Ice caps and glaciers C Lakes D Oceans

Answer B Correct. Ice caps and glaciers represent 68.7% of fresh water, which is the majority.

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.

Answer B Correct. Symbiosis is a close, extended relationship between two organisms of different species that benefits at least one member. Both humans and bacteria benefit from this relationship.

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

Answer D Correct. 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 describes gross primary productivity in an ecosystem? A Gross primary productivity is the total amount of energy captured by producers plus the energy used by consumers over time. B Gross primary productivity is the total amount of energy captured by producers minus the energy that producers respire over time. C Gross primary productivity is the total amount of energy lost as heat during energy transfer between trophic levels. D Gross primary productivity is the total amount of solar energy captured by producers through photosynthesis over time.

Answer D Correct. Gross primary productivity is the total rate of photosynthesis of producers in an ecosystem over time.

The net primary production of a pine forest on a lava flow on Mount Fuji is about 175,000kcal/m2/yr175,000kcal/m2/yr, and the plant respiration is estimated to be 115,000kcal/m2/yr115,000kcal/m2/yr. What is the total amount of energy transferred during photosynthesis for this ecosystem? A 60,000kcal/m2/yr60,000kcal/m2/yr B 115,000kcal/m2/yr115,000kcal/m2/yr C 175,000kcal/m2/yr175,000kcal/m2/yr D 290,000kcal/m2/yr

Answer D Correct. The total energy transferred by photosynthesis would be the gross primary productivity (GPPGPP), which can be calculated according to the formula NPP+Rp=GPP(175,00kcal/m2/year+115,000kcal/m2/year=290,000kcal/m2/year)

The underlying subsoil of this biome is permafrost, which prevents both water draining through and deep-rooted plants from growing. Additionally, there is very little precipitation per year. A Temperate grassland B Taiga C Tropical rainforest D Tundra

Answer D Correct. The underlying subsoil of tundra is permafrost, an impermeable, permanently frozen layer that prevents water from draining through it and roots from penetrating it. The tundra also receives less than 4 inches4 inches of precipitation per year.

Of the following organisms, which occupies the lowest trophic level? A Spider B Deer C Lion D Hawk E Snake

B Deer

Which of the following best describes the first law of thermodynamics? A Energy always changes from a more useful, more concentrated form to a less useful, less concentrated form. B In a closed system of constant mass, the energy involved in any physical or chemical change is neither created nor destroyed, but merely changed from one form to another. C Heat always flows from a hot body to a cold body. D Entropy of a system increases as the state of disorganization in the system increases. E In a reversible process, the entropy of the system is constant, whereas in an irreversible process, the entropy of the system increases.

B In a closed system of constant mass, the energy involved in any physical or chemical change is neither created nor destroyed, but merely changed from one form to another.

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

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? A The plants used up all of the phosphorus and potassium and left the nitrogen behind. B Primary succession always produces an abundance of nitrogen. C Bacteria in soil and in root nodules converted free nitrogen into nitrogen compounds. D The plants were able to produce nitrogen in their leaves. E More rock was weathered and broken down to release nitrogen compounds.

C Bacteria in soil and in root nodules converted free nitrogen into nitrogen compounds.

Which of the following is true of carbon as it cycles in nature? A Carbon dioxide is released during photosynthesis. B Carbon compounds rarely exist in the gaseous state. C Carbon sinks include forests and oceans. D The carbon dioxide concentration in the atmosphere is reduced by cutting trees. E Carbon is concentrated in igneous rocks.

C Carbon sinks include forests and oceans.

How does the burning of fossil fuels contribute to the net increase in atmospheric carbon? A Photosynthesis is reduced by virtue of increased smoke and haze. B Carbon released by the burning is not in a form that can be readily absorbed by plants, leaving residual carbon in the atmosphere. C Carbon that has been sequestered underground is added to the carbon cycling between the atmosphere and the biosphere. D Carbon released by the burning is more easily absorbed in the atmosphere than that produced by natural means. E Carbon released by the burning increases plant growth, producing more carbon for the atmosphere.

C Carbon that has been sequestered underground is added to the carbon cycling between the atmosphere and the biosphere.

For a primary producer, the main function of photosynthesis is to manufacture A oxygen B carbon dioxide C glucose D proteins E water

C glucose

The net annual primary productivity of a particular wetland ecosystem is found to be 8,000 kcal/m2 per year. If respiration by the aquatic producers is 12,000 kcal/m2 per year, what is the gross annual primary productivity for this ecosystem, in kcal/m2 per year? A 4,000 B 8,000 C 12,000 D 20,000 E 96,000

D 20,000

Decreased by the breakdown of organic waste A Acidity B Turbidity C Hardness D Dissolved oxygen E Salinity

D Dissolved oxygen

Guano from fish-eating birds is a commercial source of this element. A Carbon B Sodium C Sulfur D Phosphorus E Potassium

D Phosphorus

Traveling southward from the Arctic regions of Canada to the tropics of Panama, one passes through several biomes - tundra, coniferous forest, temperate deciduous forest, and tropical rain forest. This pattern of change in vegetation is primarily the result of A primary and secondary succession B the invasion of exotic species C an increase in mean annual temperature and a decrease in mean annual precipitation D an increase in both mean annual temperature and mean annual precipitation E an increase in the total annual hours of sunlight

D an increase in both mean annual temperature and mean annual precipitation

The major biological source of dissolved oxygen in the ocean comes from A decomposition of organic sediments on the ocean floor B metabolic processes of coral in reefs C oxidation of sulfur by bacteria in ocean vent communities D photosynthesis by phytoplankton E respiration by zooplankton

D photosynthesis by phytoplankton

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