Unit 9 Progress Check: MCQ | AP Environmental Science

Which of the following best describes why there has been a reduction in ozone depletion over the last half of the twentieth century?

D) A global plan to decrease CFC emissions was enacted by signing the Montreal Protocol. Correct. In order to decrease the ozone hole over Antarctica, CFCs needed to be regulated on a global scale. The Montreal Protocol called for a global reduction in CFC emissions and an eventual phaseout of most forms of CFCs all together. The Montreal Protocol is an international treaty that was signed by 197 countries in 1986.

Which of the following best describes how ocean acidification harms coral reefs?

D) Acidification decreases the amount of carbonate ions, which leads to a decline in the formation of reef infrastructure. Correct. Ocean acidification reduces the carbonate ions dissolved in the ocean, which coral reefs need in order to grow. Acidification makes it harder for corals to build their skeletons.

Which of the following best identifies the primary cause of increasing acidity in the oceans?

D) Carbon dioxide emissions from the combustion of fossil fuels Correct. Burning fossil fuels contributes to an increase in atmospheric carbon dioxide levels, which can be absorbed by the oceans. The carbon dioxide reacts with seawater to form carbonic acid, which increases the acidity of the oceans.

Which of the following gases has the greatest impact on global climate change as a result of having the highest global warming potential (GWP) ?

D) Chlorofluorocarbons Correct. CFC−11 has a GWP of 7020 (20 years) or 5350 (100 years). CFCs have the highest GWP followed by nitrous oxide and then methane.

The graph above shows CO2 measurements taken from Mauna Loa, Hawaii, and the Vostok ice core, which was drilled from ice sheets in Antarctica. Based on the data shown in the graph, which of the following is the most plausible hypothesis about the number of glacial periods that occurred in the past 400,000 years?

D) Four glacial periods occurred in the past 400,000 years. Correct. There are four periods (~360,000-330,000, ~260,000-240,000, ~175,000-135,000, and ~60,000-15,000 years ago) of lower-than-average CO2 levels, indicating extended periods of lower surface temperatures associated with glacial periods.

Hydrochlorofluorocarbons (HCFCs) are human-made chemicals that have been used as temporary replacements for chlorofluorocarbons (CFCs) in refrigerants because they decompose more readily in the atmosphere and thus pose less of a threat to Earth's protective ozone layer. Levels of HCFCs have been measured in the stratosphere, and the concentrations of many different HCFCs have been steadily increasing since the mid- to late 1990s. HCFCs were originally introduced as a solution to help phase out the use of CFCs. Which of the following most likely contributed to the increased levels of HCFCs in the stratosphere over the past 30 years?

D) Leaking of refrigeration and air-conditioning units Correct. The increase of HCFCs in the atmosphere can be attributed to the increased use of HCFCs as substitutes for CFCs as refrigerants, air-conditioning fluids, and other solvents or cleaning agents. Once the use of HCFCs was encouraged to help phase out CFCs and other ozone-depleting gases, HCFC concentrations rose rapidly.

American crocodiles thrive in healthy estuaries and are found distributed across southern Florida, the Caribbean islands, and in parts of northern South America. The American crocodile has always been considered rare in the state of Florida, and restoration efforts have been in effect for decades to aid the crocodile in heavily populated coastal areas. Which of the following best describes how the American crocodile has become endangered in the state of Florida?

D) The increasing use of coastal areas by human has destroyed much of the habitat of the species. Correct. The primary reason for the population decline has been habitat loss in the coastal areas of Florida. Development in the region led to the American crocodile being listed as endangered in 1975.

Since 1901, the sea level across the globe has risen over 20cm20cm. The change in sea level can be affected by land movement. Land movement itself can be caused by subsiding coastal lands, oil and water extraction, and plate tectonics. The diagram shows the relative sea level rise at various coastal locations in the United States from 1960 to 2014. Based on the information in the map, which of the following is a likely consequence for the human population if the sea level continues to change in the same pattern?

D) There will be in an increase in the number of individuals who live in flood prone regions, and there will be an increase in the number of properties at risk of flooding. Correct. Based on the highlighted areas in the map, approximately 25 million people now live in areas that are vulnerable to flooding. The highly populated regions in the Northeast are now more likely to flood, which will increase the number of individuals and the number of properties that would be affected by flooding.

Which of the following changes are linked to an increase in ocean water temperature?

A) An increase in metabolism in marine species and a decrease in dissolved oxygen in ocean water Correct. Metabolic rates of marine species increase as ocean temperature increases because biochemical reactions speed up in warmer water conditions. Also, oxygen cannot dissolve in warm water as easily as in cold water, so levels of dissolved oxygen are reduced.

Which of the following is the primary cause of stratospheric ozone depletion?

A) Chlorine atoms in CFCs Correct. When CFCs rise into the stratosphere, ultraviolet (UV) light breaks carbon-chlorine bonds in CFCs, releasing chlorine (Cl) atoms. The Cl atoms reacts with ozone (O3), breaking the O3 molecules apart.

American crocodiles thrive in healthy estuaries and are found distributed across southern Florida, the Caribbean islands, and in parts of northern South America. The American crocodile has always been considered rare in the state of Florida, and restoration efforts have been in effect for decades to aid the crocodile in heavily populated coastal areas. Which of the following claims about crocodile nests is best supported by the data in the maps?

A) Crocodiles now nest in areas where they did not nest historically as a result of restoration projects at public beaches, county parks, and other areas. Correct. Based on the data in the maps, there is an increase in the number and distribution of nesting sites.

Which of the following would most likely promote biodiversity in a given area?

A) Increased use of habitat corridors between fragmented ecosystems Correct. Habitat corridors connect wildlife populations that have been separated by human activities, such as roads, pipelines, or trails. Corridors connect wildlife populations even in disturbed habitats. This would most likely increase the species richness of a given area.

Since 1901, the sea level across the globe has risen over 20cm20cm. The change in sea level can be affected by land movement. Land movement itself can be caused by subsiding coastal lands, oil and water extraction, and plate tectonics. The diagram shows the relative sea level rise at various coastal locations in the United States from 1960 to 2014. Based on the information in the map, which areas in the United States have experienced the greatest sea level rise?

A) The Northeast and the Gulf of Mexico Correct. According to the map, the greatest increases are along the east coast (especially the Northeast) and in the Gulf of Mexico (especially in Texas and Louisiana).

The stratospheric ozone layer benefits life on Earth by

A) absorbing 99% of incoming UV-B and UV-C radiation Correct. UV-B and UV-C radiation can cause significant damage to DNA and body tissues. The ozone layer absorbs almost all UV-B and all UV-C radiation, preventing it from getting to the surface of Earth, which makes it habitable for living things.

Which of the following best describes an example of a harmful effect of an invasive species on biodiversity?

B) Asian carp outcompete native fish species in rivers in the United States. Correct. An invasive species can outcompete native species for food and habitat, decreasing the number (and biodiversity) of the native species. Asian carp were first introduced in the United States in the 1970s and have spread quickly because they lack any natural predators.

Which of the following correctly identifies the three main characteristics associated with the hole in the ozone layer?

B) CFCs, South Pole, Ultra violet Correct. Chlorofluorocarbons (CFCs) are the main chemical agent responsible for causing the formation of the stratospheric ozone hole. CFCs in the presence of the Sun's energy (UV) in the Antarctic spring break down the O3 in the ozone layer, allowing more UV radiation to enter the stratosphere. This process occurs over the South Pole because cold temperatures that are necessary to catalyze the reaction are only found over Antarctica. Ultraviolet (UV) radiation is the form of radiation that is able to enter the Earth's atmosphere with a decrease in the protective stratospheric ozone layer.

Which of the following best describes why carbon dioxide has a significant effect on global climate change?

B) Carbon dioxide is the largest contributor to anthropogenic greenhouse gas emissions. Correct. In comparison with equal amounts of other greenhouse gases, carbon dioxide has a lower global warming potential. However, because carbon dioxide is released from anthropogenic sources in such large quantities compared with other greenhouse gases, it has a very large effect on global climate change.

Sea surface temperatures in the Caribbean Sea have increased over the past 30 years. Which of the following is the most likely cause for the warming trend?

B) Elevated levels of atmospheric CO2 Correct. Carbon dioxide (CO2) is a greenhouse gas that traps heat near Earth's surface. CO2 (and other greenhouse gases) have increased in the atmosphere, especially over the past 200 years, and are the most likely cause of the increased sea surface temperatures.

Which of the following best describes the cause of the greenhouse effect on Earth?

B) Gases in the atmosphere absorb infrared radiation and radiate the energy back toward Earth's surface. Correct. The greenhouse effect is so named because of how an actual greenhouse is naturally warmed by solar radiation. However, an actual greenhouse is warmed by glass windows trapping heat, while Earth's greenhouse effect is caused by gases (such as CO2 and CH4) in the atmosphere reflecting infrared energy back toward Earth's surface, causing a warming effect.

The graph above shows CO2 measurements taken from Mauna Loa, Hawaii, and the Vostok ice core, which was drilled from ice sheets in Antarctica. Based on the data shown in the graph, which of the following is the most plausible hypothesis for the cause of the trend in CO2 levels from about 5,000 years ago to the present?

B) Human activity, especially the burning of fossil fuels, has led to an increase in anthropogenic carbon dioxide emissions. This has caused a doubling in the concentration of CO2 in the atmosphere.

Which of the following actions best explains a cause of increasing ocean acidification?

B) Reliance on fossil fuels for electricity generation emits carbon dioxide to the atmosphere, which is absorbed by the ocean, leading to a decrease in the pH in the ocean. Correct. Ocean acidification is caused by increased CO2 in the atmosphere and oceans. Burning of fossil fuels increases the addition of CO2 into the atmosphere, which will therefore increase ocean acidification (and decrease the pH of the ocean).

American crocodiles thrive in healthy estuaries and are found distributed across southern Florida, the Caribbean islands, and in parts of northern South America. The American crocodile has always been considered rare in the state of Florida, and restoration efforts have been in effect for decades to aid the crocodile in heavily populated coastal areas. Which of the following best describes a likely unintended consequence of the restoration plan based on the data in the map?

B) There will be an increase in the number of human and crocodile interactions in coastal areas. Correct. As the number and range of crocodiles increase during the ecosystem restoration and management, there is a challenge to integrate the recovering crocodile population into the coastal areas that are heavily used by humans.

Which of the following best describes the effect of increasing global temperature on coral ecosystems?

C) Algae that live symbiotically with the corals leave the reef, causing coral bleaching. Correct. An algae called zooxanthellae live symbiotically with the coral polyp. When the temperature of the water gets too warm, the zooxanthellae leave the safety of the coral to continue photosynthesizing in cooler waters. This causes the coral to lose its coloring from the zooxanthellae and is called coral "bleaching" because the limestone coral is left without the colorful algae to provide color to the coral.

Based on the information in the diagram, which of the following best supports the claim that a change in the duration of warm seasons would result in a higher prevalence of vector-borne diseases?

C) Increased temperatures provide an expanded breeding range and duration, which will likely increase the size of vector populations. Correct. Warmer temperatures in a broader range of locations extend the mating seasons and reproductive opportunities for vectors.

Which of the following could directly lead to a loss of biodiversity as an unintended consequence of human actions?

C) Mangrove forests are removed as part of a beach development project. Correct. The loss of mangrove forests would result in a decrease in local biodiversity. Removal of mangrove forests as part of a commercial construction project is an example of direct human action.

The graph above shows CO2CO2 measurements taken from Mauna Loa, Hawaii, and the Vostok ice core, which was drilled from ice sheets in Antarctica. Which of the following hypotheses is best supported by the graph?

C) Temperatures were warmer 125,000 years ago than the average temperature over the past 400,000 years. Correct. The CO2 levels 125,000 years ago were higher than average, suggesting higher-than-average temperatures.

Hydrochlorofluorocarbons (HCFCs) are human-made chemicals that have been used as temporary replacements for chlorofluorocarbons (CFCs) in refrigerants because they decompose more readily in the atmosphere and thus pose less of a threat to Earth's protective ozone layer. Levels of HCFCs have been measured in the stratosphere, and the concentrations of many different HCFCs have been steadily increasing since the mid- to late 1990s. One important drawback of the use of HCFCs as a replacement for CFCs is that HCFCs

C) are greenhouse gases that contribute to climate change Correct. HCFCs are greenhouse gases with a global warming potential (GWP) in the range of 70 to almost 2000 over a 100-year period.