Science Section 3 - Part 2 Flashcards
In what year did the human population reach 2 billion?
1927
By how many more people did the population increase in 1963 compared to 2023?
6 million
All of the following factors directly determine the growth rate of a country
deaths, emigration, immigration, and births
DOES NOT directly determine growth rate - development
The most basic measure of birth rate determines the
number of births per 1,000 individuals per year
Approximately what percentage of people worldwide live in lower-income countries?
80 percent
What BEST describes population growth in less developed and more developed nations?
In less developed countries, population growth occurs quickly, while more developed countries have minimal population growth.
The processes to develop, use, and dispose of resources lead to
environmental degradation
In which decade did fossil fuel use reach the equivalent of 3,000 million tons of oil?
1960s
In the human population system, the number of deaths subtracted from the number of births represents the system’s
flux
The United States has a fertility rate of approximately
1.8
What term describes the fertility rate needed to maintain the current population?
replacement fertility rate
Why do life expectancies differ for men and women?
Men experience greater workplace risks and choose different lifestyles than women.
Why does the crude death rate make a poor indicator of a country’s healthcare?
Countries with an older population will have a higher crude death rate despite proper healthcare.
Which of the following countries does NOT have a lower infant mortality rate than the United States?
a. France
b. China
c. Canada
d. Japan
e. Ireland
China
The infant mortality rate for Black Americans exceeds the overall United States infant mortality rate by a factor of approximately
2
The %<15/%>65 value describes a country’s
age structure
Nigeria has a %<15/%>65 value of
41/3.3
The two halves of an age-structure diagram represent the age distributions
by gender
Which of the following countries has a distinctly shaped age-structure diagram from the others?
a. Germany
b. Ghana
c. Haiti
d. Nigeria
e. Uganda
Germany
What fertility rate would create a column-like pattern in the age-structure diagram of a country?
2.1 maintains a stable population size
Info: Stable populations have a column-like age-structure diagram because the number of individuals of all ages is relatively consistent
Approximately how many individuals aged 30 to 34 did the world have in 2024?
600 million
What countries have an aging population?
Italy, Germany, and Japan
Of Earth’s layers, the thickest layer is the
mantle
What percentage of the Earth consists of iron?
35%
What layer of the Earth has a thickness of less than fifty kilometers?
crust
Of the following gases, the atmosphere contains the greatest amount of
a. methane
b. hydrogen
c. ozone
d. argon
e. carbon dioxide
argon
How do plants obtain nutrients?
Plants obtain the aqueous form of elements from soil water.
What term describes the breakdown of rock to free elements?
weathering
The dust storms of the 1920s and 1930s in the western United States transported
Calcium and magnesium
Ecologists classify soil organisms as
organic matter recyclers
What classification describes the uppermost layer of soil in forests?
O horizon, an additional layer of organic matter which is on top of their A horizon
In what soil type would scientists find an E horizon?
acidic
The C horizon bears many similarities to the
parent material
What component has a large effect on soil properties despite making up a small portion of most soils?
organic matter
What variables do scientists classify as state variables?
topography, parent material, time, climate
What state borders Lake Champlain?
Vermont and New York
Leaching tends to affect
warm moist soils
Compared to leeward soils, windward soils
receive more precipitation
What organisms contribute LEAST to a soil’s biological activity?
macrofauna
What organisms contribute significantly to a soil’s biological activity?
fungi, bacteria, archaea, and protozoa
Earthworms do NOT
reduce habitat acidity
What particle has a diameter between 0.002 mm and 0.05 mm?
silt
Which of the following locations contains soils with large A and B horizons?
a. United States grasslands
b. Sahara desert
c. Canadian Arctic
d. Hawaiian islands
e. Icelandic glacial deposits
United States grasslands
By what percentage has food production decreased worldwide due to soil degradation?
17 percent reduction
Soils recover from degradation more quickly in places with
moderate temperatures and precipitation levels
Why were aqueducts first built?
to avoid pollution
When was the first Roman aqueduct built?
312 BCE
Why do historians think the Roman Empire’s aristocracy declined?
Lead content in water led to adverse neurological effects.
What structures were built to filter trash out of aqueduct water?
settling basins
What aqueduct did Frontinus say could be used to water gardens?
Old Anio
What percentage of water on Earth do lakes, rivers, and reservoirs contain?
.009%
How does most water enter the groundwater system?
river and stream runoff
About how much freshwater is in the atmosphere?
.001%
What geographical formation impedes the flow of groundwater?
aquiclude, an underground layer of impermeable clay in an aquifer
What process involves evaporating water to remove salt?
distillation, which is a form of desalination
How many gallons of water did the average American use per day in 2023?
1,300 gallons
Why is drip irrigation not feasible for most farmers?
large capital investments
What aquifer runs from Texas and New Mexico up to South Dakota?
Ogallala Aquifer
In which Indian state did a flood destroy more than 800,000 homes in 2000?
West Bengal
How can floods, hurricanes, and torrential rains MOST directly improve the environment?
They help improve soil quality.
Which of the following sites would NOT be considered a point source of pollution?
a. a sewage treatment plant
b. a mine in the Rocky Mountains
c. a contaminated pipe
d. a plantation in the Amazon
e. a power plant
a plantation in the Amazon
Locating point sources of pollution PRIMARILY allows for
targeted cleanup efforts
The two major worldwide water-borne diseases are
cholera and hepatitis
What bacterium has caused domestic gastrointestinal disease outbreaks in the United States?
Cryptosporidium
The Giarda intestinal parasite entered natural waters through
hikers
What component of oxygen-demanding waste depletes oxygen?
bacteria
Biochemical oxygen demand is defined as the amount of oxygen
used up by a defined quantity of water over a specified period of time
What is the leading cause of water pollution in the United States?
pathogens
Dissolved oxygen in bodies of water is measured in
parts per million
Eutrophication can be caused by overabundance of
nitrogen and phosphorus
Eutrophication of water will NOT lead to
a. increases in dissolved oxygen
b. increases in biochemical oxygen demand
c. overabundance of nutrients
d. death of native species
e. excessive growth of algae
increases in dissolved oxygen
What locations are the largest contributors to mercury emissions in the United States?
fossil fuel power plants
Exposure to methylmercury can result in damage to the human
central nervous system
Which products were historically manufactured using polychlorinated biphenyls?
a. automobiles and metal tools
b. pesticides and hairsprays
c. cement and paper products
d. perfumes and fertilizers
e. plastics and electrical transformers
plastics and electrical transformers
What company was ordered in 2002 to remove polychlorinated biphenyl-contaminated sediment in the Hudson River?
General Electric
What type of fish does sediment MOST negatively affect?
bottom dwellers
Info: Sediment negatively affects fish by clogging their gills and impeding their access to oxygen. Bottom dwellers like oysters and clams experience these effects the most.
All of the following changes are likely to increase the temperature of water EXCEPT
a. restricting the width of the waterway
b. using water for cooling in industrial settings
c. exposing water to more sunlight
d. slowing the speed of water
e. limiting the flow of chemicals into water
limiting the flow of chemicals into water
All of the following effects are examples of thermal pollution
water organisms increasing their respiration rate
less oxygen being dissolved in the water
the reproduction of water organisms becoming affected
water organisms becoming more susceptible to disease
What organisms make up the base of the aquatic food chain?
algae, microorganisms
Which source of oil entering the ocean is MOST notable?
a. spills from fishing crafts and cruise ships
b. runoff carrying chemicals from agricultural areas
c. products from undersea mining expeditions
d. spills from off-shore drilling and oil tankers
e. pollution from planned construction projects
spills from off-shore drilling and oil tankers
What oil spill was the MOST notorious in the twenty-first century?
Deepwater Horizon oil spill
What term describes all plastic particles smaller than 5mm?
microplastics, which are a health risk to animals and humans
Wastewater refers to
water destined for sewage treatment plants
Whattype of water can be reintroduced to the environment without undergoing treatment?
gray water, which is water used in sinks or showers
What stage of wastewater treatment removes 40 to 50 percent of solid waste material?
primary treatment
Sludge from industrial business areas contains
above average amounts of metals
What function does an aeration tank perform in the wastewater treatment process?
moving effluent into a secondary clarifier
What two regulations did the Clean Water Act establish?
Water Quality Standards; Total Maximum Daily Load
What source of pollutants is considered a point source?
wastewater treatment center
Maximum contaminant levels are BEST described as
enforceable levels to limit contaminants
The introduction of agriculture MOST directly led to
exponential population growth
What location was NOT among the first to develop agriculture?
Western Europe
What biome contains the MOST nutrient-rich soil?
Southeast Asian floodplain
What farming method has historically been MOST widely used in Central and South America?
slash-and-burn agriculture
In intercropping, corn is MOST effectively paired with
peas
In what country did Norman Borlaug do his work on “miracle wheat”?
Mexico
What was NOT a defining characteristic of the Green Revolution?
a. increased use of machinery
b. development of better crop varieties
c. use of synthetic fertilizers
d. intensification of monoculture
e. harnessing naturally found nitrogen
harnessing naturally found nitrogen
How many different crop species provide ninety-five percent of the calories for human diets?
thirty
80% of the calories consumed by humans comes from what plants?
Wheat, rice, maize, potatoes, sweet potatoes, and manioc
What two varieties of wheat did Norman Borlaug cross to form the strain of “miracle wheat”?
Japanese and Mexican
How many kilocalories does an average diet require daily?
2,200 kilocalories
What prediction did the United Nations make about the future of food production?
Production will need to increase to feed a growing population.
What two crops in the United States are mainly fed to livestock?
corn and soybeans
How much of the modern global population is considered obese or overnourished?
one-eighth
How many pounds of grain must be fed to livestock to obtain the equivalent of one pound of beef?
7 pounds
What is a major cause of modern-day global starvation?
inaccessible food prices
All of the following beneficial effects are attributable to tilling
increased root penetration, soil aeration, faster seed germination, burying weeds
What agricultural activity contributes MOST to erosion?
tilling
Approximately what percent of global soil has been lost to erosion?
16 percent
Land that is left absent of crops during the growing season is called
fallow land
All of the following irrigation types are widely deployed
flood irrigation, drip irrigation, spray irrigation, and furrow irrigation
In what state is the Imperial Valley located?
California
What negative effects is MOST associated with irrigation in dry regions?
aquifer depletion
What crop makes up the bulk of Kenyan agriculture?
tea
What economic concept is MOST related to monoculture?
economies of scale
Info: The practice of monoculture is a result of economies of scale. By growing a large amount of one crop, the price per unit decreases.
What consequences is associated with monoculture?
increased pest risk
What element is captured from natural gas combustion for use in fertilizer?
nitrogen
Why do chemical fertilizers result in more nutrient runoff than compost?
Chemical fertilizers release nutrients faster.
What chemical compound is MOST common in pesticides?
petroleum
What herbicides is sold commercially as Roundup?
glyphosate
Approximately how many pesticide poisonings are treated each year in the United States?
20,000
Info: Roughly 20,000 cases of pesticide poisoning are treated each year in the U.S., comprising 0.5% of all agricultural workers. While this number may seem small, it means that if an agricultural worker works for 10 years, they have as high as a 5% chance of being poisoned
What evidence did the May 2003 article from the journal Nature use to prove that many fish species are facing extinction due to overfishing?
an analysis of the amount of large predatory ocean fish that major fisheries caught over time
What fish species is a large predatory ocean fish?
tuna and swordfish
One direct cause of overfishing is
fishing quotas that are set too high
Fifty years ago, dory fishing could be described in all of the following ways
hands-on, sustainable, dangerous, and low-yield
What fishing method targets schools of single-species fish and involves a vertical net that surrounds a school of fish?
Purse seine
Info: A vertical net is cast into the water, surrounding a school. The bottom of the net is then drawn together, like a drawstring purse.
What fishing method is deployed on the seabed and is used to catch crustaceans?
Pots and traps
What term describes species of fish whose decline would cause a cascade effect, resulting in the decline of other species?
keystone species
How long did the Alaska salmon fishing season last in 1970?
5 days
What fish species’ ecological concerns led to the implementation of individual transferable quotas (ITQs) in Alaska?
salmon
Where is the ITQ system being used successfully to prevent overfishing from large fishing companies?
New Zealand
What organization managed the two-hundred-mile exclusive fishery zone around the United States established in 1976?
National Marine Fisheries Service
Why did the United States’ Northwest Atlantic fisheries experience a huge depletion of fish stock in the early 1990s?
overfishing by international factory ships
When was the United States Sustainable Fisheries Act passed?
1996
From which fishing area did Michael Fogarty and Steven Murawski analyze decades of data?
Georges Bank
What activity is never allowed in a marine protected area?
drilling for oil
What term describes the management of forest ecosystems for human benefit?
silviculture
The cycles of replanting and harvesting trees are known in renewability as
rotations
The age, species composition, and physical environment in the stand of a forest can be described as
uniform
Clearcutting is the ideal harvesting method for trees that are
fast growing and require lots of sunlight
What method of harvesting trees is MOST complicated?
shelterwood cutting
Info: cutting specific sections while allowing for regrowth in the understory.
Intensive forestry and intensive agriculture both primarily aim to
maximize short-term profits
A single stand of trees can represent most of the genetic diversity for
commercial tree species
What tree species is the major commercial species of the southern United States?
loblolly pine, spanning 1.5 million acres in 1992
Foresters include “natural” tree species in selective breeding programs to
maintain genetic variation
What person was a key creator of ecologically sustainable forestry?
Aldo Leopold
The industry for fine tropical woods is valued per year at
8 billion dollars
What two techniques does sustainable commercial forestry involve?
selective logging in natural forests; monocultures in plantations
About how many acres of tropical forests were destroyed between 1985 and 1990?
200 million acres
What scientist studied butterfly population changes in response to deforestation in Borneo?
John Willott
What aspect of butterfly populations in Borneo was logging found to affect MOST?
community-level biodiversity
The amount of Earth’s population that lives in developing countries is approximately
four-fifths
All of the following population parameters measure current or future patterns EXCEPT
a. population mean
b. mortality rate
c. fertility rate
d. doubling time
e. population size
population means
Which of the following growth types occurs when a population is not limited by any means?
a. arithmetic
b. linear
c. geometric
d. exponential
e. logistic
exponential
Which of the following processes is NOT part of the carbon cycle?
a. photosynthesis
b. combustion
c. respiration
d. decomposition
e. transpiration
transpiration
The process in which atmospheric nitrogen is formed into compounds used for plants is called
nitrogen fixation
Which of the following events occurs when excess nutrients enter a body of water?
a. eutrophication
b. biomagnification
c. photosynthesis
d. sedimentation
e. evaporation
eutrophication
What is the name of the federal law that governs water pollution in the United States?
Clean Water Act
Which of the following periods refers to the shift from small to large-scale agricultural businesses?
a. Green Revolution
b. Environmental Movement
c. Industrial Revolution
d. Organic Farming Movement
e. Agricultural Adjustment Act
Green Revolution
Which term among the following has sparked controversy due to its detrimental effects on natural crop varieties?
a. polyculture
b. no-till farming
c. monoculture
d. clear-cutting
e. GMOs
GMOs
Which of the following terms describe the overuse of shared resources?
a. species extinction
b. ecological footprint
c. habitat fragmentation
d. tragedy of the commons
e. ecosystem services
tragedy of the commons
This ecosystem covers about 35 percent of Earth’s surface
forests
